2009-03-23 15:05:40

by Daniel Glöckner

[permalink] [raw]
Subject: [patch 1/5] i2c: xtensa s6000 i2c driver

From: Oskar Schirmer <[email protected]>

Support for the s6000 on-chip i2c controller.

Signed-off-by: Oskar Schirmer <[email protected]>
Signed-off-by: Daniel Glöckner <[email protected]>
---
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-s6000.c | 380 ++++++++++++++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-s6000.h | 79 +++++++++
include/linux/i2c/s6000.h | 10 +
5 files changed, 480 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-s6000.c
create mode 100644 drivers/i2c/busses/i2c-s6000.h
create mode 100644 include/linux/i2c/s6000.h

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7f95905..904def4 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -461,6 +461,16 @@ config I2C_S3C2410
Say Y here to include support for I2C controller in the
Samsung S3C2410 based System-on-Chip devices.

+config I2C_S6000
+ tristate "S6000 I2C support"
+ depends on XTENSA_VARIANT_S6000
+ help
+ This driver supports the on chip I2C device on the
+ S6000 xtensa processor family.
+
+ To compile this driver as a module, choose M here. The module
+ will be called i2c-s6000.
+
config I2C_SH7760
tristate "Renesas SH7760 I2C Controller"
depends on CPU_SUBTYPE_SH7760
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 0c2c4b2..f7989d1 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
+obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
diff --git a/drivers/i2c/busses/i2c-s6000.c b/drivers/i2c/busses/i2c-s6000.c
new file mode 100644
index 0000000..88e3fdc
--- /dev/null
+++ b/drivers/i2c/busses/i2c-s6000.c
@@ -0,0 +1,380 @@
+/*
+ * drivers/i2c/busses/i2c-s6000.c
+ *
+ * Description: Driver for S6000 Family I2C Interface
+ * (c) 2008 emlix GmbH <[email protected]>
+ * Author: Oskar Schirmer <[email protected]>
+ *
+ * Partially based on i2c-bfin-twi.c driver by <[email protected]>
+ * Copyright (c) 2005-2007 Analog Devices, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/i2c/s6000.h>
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <asm/io.h>
+#include "i2c-s6000.h"
+
+#define POLL_TIMEOUT (2 * HZ)
+
+struct s6i2c_if {
+ u8 __iomem *reg;
+ int irq;
+ spinlock_t lock;
+ struct i2c_msg *msgs;
+ int msgs_num, msgs_push, msgs_done;
+ unsigned push, done;
+ int timeout_count;
+ struct timer_list timeout_timer;
+ struct i2c_adapter adap;
+ struct completion complete;
+ struct clk *clk;
+ struct resource *res;
+};
+
+#define I2C_RD16(iface, n) readw(iface->reg + (n))
+#define I2C_WR16(iface, n, v) writew(v, iface->reg + (n))
+#define I2C_RD32(iface, n) readl(iface->reg + (n))
+#define I2C_WR32(iface, n, v) writel(v, iface->reg + (n))
+
+static struct s6i2c_if s6i2c_if;
+
+static void s6i2c_handle_interrupt(struct s6i2c_if *iface)
+{
+ if (I2C_RD16(iface, S6_I2C_INTRSTAT) & (1 << S6_I2C_INTR_TXABRT)) {
+ I2C_RD16(iface, S6_I2C_CLRTXABRT);
+ I2C_WR16(iface, S6_I2C_INTRMASK, 0);
+ complete(&iface->complete);
+ return;
+ }
+ if (iface->msgs_done >= iface->msgs_num) {
+ printk(KERN_DEBUG "spurious I2C irq: %x\n",
+ I2C_RD16(iface, S6_I2C_INTRSTAT));
+ I2C_WR16(iface, S6_I2C_INTRMASK, 0);
+ return;
+ }
+ while ((iface->msgs_push < iface->msgs_num)
+ && (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_TFNF))) {
+ struct i2c_msg *m = &iface->msgs[iface->msgs_push];
+ if (!(m->flags & I2C_M_RD))
+ I2C_WR16(iface, S6_I2C_DATACMD, m->buf[iface->push]);
+ else
+ I2C_WR16(iface, S6_I2C_DATACMD,
+ 1 << S6_I2C_DATACMD_READ);
+ if (++iface->push >= m->len) {
+ iface->push = 0;
+ iface->msgs_push += 1;
+ }
+ }
+ do {
+ struct i2c_msg *m = &iface->msgs[iface->msgs_done];
+ if (!(m->flags & I2C_M_RD)) {
+ if (iface->msgs_done < iface->msgs_push)
+ iface->msgs_done += 1;
+ else
+ break;
+ } else if (I2C_RD16(iface, S6_I2C_STATUS)
+ & (1 << S6_I2C_STATUS_RFNE)) {
+ m->buf[iface->done] = I2C_RD16(iface, S6_I2C_DATACMD);
+ if (++iface->done >= m->len) {
+ iface->done = 0;
+ iface->msgs_done += 1;
+ }
+ } else{
+ break;
+ }
+ } while (iface->msgs_done < iface->msgs_num);
+ if (iface->msgs_done >= iface->msgs_num) {
+ I2C_WR16(iface, S6_I2C_INTRMASK, 1 << S6_I2C_INTR_TXABRT);
+ complete(&iface->complete);
+ } else if (iface->msgs_push >= iface->msgs_num) {
+ I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
+ (1 << S6_I2C_INTR_RXFULL));
+ } else {
+ I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
+ (1 << S6_I2C_INTR_TXEMPTY) |
+ (1 << S6_I2C_INTR_RXFULL));
+ }
+}
+
+static irqreturn_t s6i2c_interrupt_entry(int irq, void *dev_id)
+{
+ struct s6i2c_if *iface = dev_id;
+ if (!(I2C_RD16(iface, S6_I2C_STATUS) & ((1 << S6_I2C_INTR_RXUNDER)
+ | (1 << S6_I2C_INTR_RXOVER)
+ | (1 << S6_I2C_INTR_RXFULL)
+ | (1 << S6_I2C_INTR_TXOVER)
+ | (1 << S6_I2C_INTR_TXEMPTY)
+ | (1 << S6_I2C_INTR_RDREQ)
+ | (1 << S6_I2C_INTR_TXABRT)
+ | (1 << S6_I2C_INTR_RXDONE)
+ | (1 << S6_I2C_INTR_ACTIVITY)
+ | (1 << S6_I2C_INTR_STOPDET)
+ | (1 << S6_I2C_INTR_STARTDET)
+ | (1 << S6_I2C_INTR_GENCALL))))
+ return IRQ_NONE;
+
+ spin_lock(&iface->lock);
+ del_timer(&iface->timeout_timer);
+ s6i2c_handle_interrupt(iface);
+ spin_unlock(&iface->lock);
+ return IRQ_HANDLED;
+}
+
+static void s6i2c_timeout(unsigned long data)
+{
+ struct s6i2c_if *iface = (struct s6i2c_if *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&iface->lock, flags);
+ s6i2c_handle_interrupt(iface);
+ if (--iface->timeout_count > 0) {
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ } else {
+ complete(&iface->complete);
+ I2C_WR16(iface, S6_I2C_INTRMASK, 0);
+ }
+ spin_unlock_irqrestore(&iface->lock, flags);
+}
+
+static int s6i2c_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct s6i2c_if *iface = adap->algo_data;
+ int i;
+ if (num == 0)
+ return 0;
+ if (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
+ yield();
+ I2C_WR16(iface, S6_I2C_INTRMASK, 0);
+ I2C_RD16(iface, S6_I2C_CLRINTR);
+ for (i = 0; i < num; i++) {
+ if (msgs[i].flags & I2C_M_TEN) {
+ dev_err(&(adap->dev),
+ "s6i2c: 10 bits addr not supported\n");
+ return -EINVAL;
+ }
+ if (msgs[i].len == 0) {
+ dev_err(&(adap->dev),
+ "s6i2c: zero length message not supported\n");
+ return -EINVAL;
+ }
+ if (msgs[i].addr != msgs[0].addr) {
+ dev_err(&(adap->dev),
+ "s6i2c: multiple xfer cannot change target\n");
+ return -EINVAL;
+ }
+ }
+ iface->msgs = msgs;
+ iface->msgs_num = num;
+ iface->msgs_push = 0;
+ iface->msgs_done = 0;
+ iface->push = 0;
+ iface->done = 0;
+ iface->timeout_count = 10;
+ I2C_WR16(iface, S6_I2C_TAR, msgs[0].addr);
+ I2C_WR16(iface, S6_I2C_ENABLE, 1);
+ I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXEMPTY) |
+ (1 << S6_I2C_INTR_TXABRT));
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ wait_for_completion(&iface->complete);
+ del_timer_sync(&iface->timeout_timer);
+ while (I2C_RD32(iface, S6_I2C_TXFLR) > 0)
+ schedule();
+ while (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
+ schedule();
+ I2C_WR16(iface, S6_I2C_INTRMASK, 0);
+ I2C_WR16(iface, S6_I2C_ENABLE, 0);
+ return iface->msgs_done;
+}
+
+static u32 s6i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm s6i2c_algorithm = {
+ .master_xfer = s6i2c_master_xfer,
+ .functionality = s6i2c_functionality,
+};
+
+static u16 __devinit nanoseconds_on_clk(struct s6i2c_if *iface, u32 ns)
+{
+ u64 dividend = (u64)ns * clk_get_rate(iface->clk);
+ do_div(dividend, 1000000000);
+ if (dividend > 0xffff)
+ return 0xffff;
+ return dividend;
+}
+
+static int __devinit s6i2c_probe(struct platform_device *dev)
+{
+ struct s6i2c_if *iface = &s6i2c_if;
+ struct i2c_adapter *p_adap;
+ const char *clock;
+ int bus_num, rc;
+ spin_lock_init(&(iface->lock));
+ init_completion(&(iface->complete));
+ iface->irq = platform_get_irq(dev, 0);
+ if (iface->irq < 0) {
+ rc = iface->irq;
+ goto err_out;
+ }
+ iface->res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!iface->res) {
+ rc = -ENXIO;
+ goto err_out;
+ }
+ iface->res = request_mem_region(iface->res->start,
+ iface->res->end - iface->res->start + 1,
+ dev->dev.bus_id);
+ if (!iface->res) {
+ rc = -EBUSY;
+ goto err_out;
+ }
+ iface->reg = ioremap_nocache(iface->res->start,
+ iface->res->end - iface->res->start + 1);
+ if (!iface->reg) {
+ rc = -ENOMEM;
+ goto err_reg;
+ }
+ clock = 0;
+ bus_num = -1;
+ if (dev->dev.platform_data) {
+ struct s6_i2c_platform_data *pdata = dev->dev.platform_data;
+ bus_num = pdata->bus_num;
+ clock = pdata->clock;
+ }
+ iface->clk = clk_get(&dev->dev, clock);
+ if (IS_ERR(iface->clk)) {
+ rc = PTR_ERR(iface->clk);
+ goto err_map;
+ }
+ rc = clk_enable(iface->clk);
+ if (rc < 0)
+ goto err_clk_put;
+ init_timer(&(iface->timeout_timer));
+ iface->timeout_timer.function = s6i2c_timeout;
+ iface->timeout_timer.data = (unsigned long)iface;
+ p_adap = &iface->adap;
+ strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
+ p_adap->algo = &s6i2c_algorithm;
+ p_adap->algo_data = iface;
+ p_adap->nr = bus_num;
+ p_adap->class = 0;
+ p_adap->dev.parent = &dev->dev;
+ I2C_WR16(iface, S6_I2C_INTRMASK, 0);
+ rc = request_irq(iface->irq, s6i2c_interrupt_entry,
+ IRQF_SHARED, dev->name, iface);
+ if (rc) {
+ dev_err(&(p_adap->dev), "s6i2c: cant get IRQ %d\n", iface->irq);
+ goto err_clk_dis;
+ }
+ I2C_WR16(iface, S6_I2C_ENABLE, 0);
+ udelay(1);
+ I2C_WR32(iface, S6_I2C_SRESET, 1 << S6_I2C_SRESET_IC_SRST);
+ I2C_WR16(iface, S6_I2C_CLRTXABRT, 1);
+ I2C_WR16(iface, S6_I2C_CON,
+ (1 << S6_I2C_CON_MASTER) |
+ (S6_I2C_CON_SPEED_NORMAL << S6_I2C_CON_SPEED) |
+ (0 << S6_I2C_CON_10BITSLAVE) |
+ (0 << S6_I2C_CON_10BITMASTER) |
+ (1 << S6_I2C_CON_RESTARTENA) |
+ (1 << S6_I2C_CON_SLAVEDISABLE));
+ I2C_WR16(iface, S6_I2C_SSHCNT, nanoseconds_on_clk(iface, 4000));
+ I2C_WR16(iface, S6_I2C_SSLCNT, nanoseconds_on_clk(iface, 4700));
+ I2C_WR16(iface, S6_I2C_FSHCNT, nanoseconds_on_clk(iface, 600));
+ I2C_WR16(iface, S6_I2C_FSLCNT, nanoseconds_on_clk(iface, 1300));
+ I2C_WR16(iface, S6_I2C_RXTL, 0);
+ I2C_WR16(iface, S6_I2C_TXTL, 0);
+ platform_set_drvdata(dev, iface);
+ if (bus_num < 0)
+ rc = i2c_add_adapter(p_adap);
+ else
+ rc = i2c_add_numbered_adapter(p_adap);
+ if (rc)
+ goto err_irq_free;
+ return 0;
+
+err_irq_free:
+ free_irq(iface->irq, iface);
+err_clk_dis:
+ clk_disable(iface->clk);
+err_clk_put:
+ clk_put(iface->clk);
+err_map:
+ iounmap(iface->reg);
+err_reg:
+ release_mem_region(iface->res->start,
+ iface->res->end - iface->res->start + 1);
+err_out:
+ return rc;
+}
+
+static int __devexit s6i2c_remove(struct platform_device *pdev)
+{
+ struct s6i2c_if *iface = platform_get_drvdata(pdev);
+ I2C_WR16(iface, S6_I2C_ENABLE, 0);
+ platform_set_drvdata(pdev, NULL);
+ i2c_del_adapter(&(iface->adap));
+ free_irq(iface->irq, iface);
+ clk_disable(iface->clk);
+ clk_put(iface->clk);
+ iounmap(iface->reg);
+ release_mem_region(iface->res->start,
+ iface->res->end - iface->res->start + 1);
+ return 0;
+}
+
+static struct platform_driver s6i2c_driver = {
+ .probe = s6i2c_probe,
+ .remove = __devexit_p(s6i2c_remove),
+ .driver = {
+ .name = "i2c-s6000",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init s6i2c_init(void)
+{
+ pr_info("I2C: S6000 I2C driver\n");
+ return platform_driver_register(&s6i2c_driver);
+}
+
+static void __exit s6i2c_exit(void)
+{
+ platform_driver_unregister(&s6i2c_driver);
+}
+
+MODULE_DESCRIPTION("I2C-Bus adapter routines for S6000 I2C");
+MODULE_LICENSE("GPL");
+
+subsys_initcall(s6i2c_init);
+module_exit(s6i2c_exit);
diff --git a/drivers/i2c/busses/i2c-s6000.h b/drivers/i2c/busses/i2c-s6000.h
new file mode 100644
index 0000000..ff23b81
--- /dev/null
+++ b/drivers/i2c/busses/i2c-s6000.h
@@ -0,0 +1,79 @@
+/*
+ * drivers/i2c/busses/i2c-s6000.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Emlix GmbH <[email protected]>
+ * Author: Oskar Schirmer <[email protected]>
+ */
+
+#ifndef __DRIVERS_I2C_BUSSES_I2C_S6000_H
+#define __DRIVERS_I2C_BUSSES_I2C_S6000_H
+
+#define S6_I2C_CON 0x000
+#define S6_I2C_CON_MASTER 0
+#define S6_I2C_CON_SPEED 1
+#define S6_I2C_CON_SPEED_NORMAL 1
+#define S6_I2C_CON_SPEED_FAST 2
+#define S6_I2C_CON_SPEED_MASK 3
+#define S6_I2C_CON_10BITSLAVE 3
+#define S6_I2C_CON_10BITMASTER 4
+#define S6_I2C_CON_RESTARTENA 5
+#define S6_I2C_CON_SLAVEDISABLE 6
+#define S6_I2C_TAR 0x004
+#define S6_I2C_TAR_GCORSTART 10
+#define S6_I2C_TAR_SPECIAL 11
+#define S6_I2C_SAR 0x008
+#define S6_I2C_HSMADDR 0x00C
+#define S6_I2C_DATACMD 0x010
+#define S6_I2C_DATACMD_READ 8
+#define S6_I2C_SSHCNT 0x014
+#define S6_I2C_SSLCNT 0x018
+#define S6_I2C_FSHCNT 0x01C
+#define S6_I2C_FSLCNT 0x020
+#define S6_I2C_INTRSTAT 0x02C
+#define S6_I2C_INTRMASK 0x030
+#define S6_I2C_RAWINTR 0x034
+#define S6_I2C_INTR_RXUNDER 0
+#define S6_I2C_INTR_RXOVER 1
+#define S6_I2C_INTR_RXFULL 2
+#define S6_I2C_INTR_TXOVER 3
+#define S6_I2C_INTR_TXEMPTY 4
+#define S6_I2C_INTR_RDREQ 5
+#define S6_I2C_INTR_TXABRT 6
+#define S6_I2C_INTR_RXDONE 7
+#define S6_I2C_INTR_ACTIVITY 8
+#define S6_I2C_INTR_STOPDET 9
+#define S6_I2C_INTR_STARTDET 10
+#define S6_I2C_INTR_GENCALL 11
+#define S6_I2C_RXTL 0x038
+#define S6_I2C_TXTL 0x03C
+#define S6_I2C_CLRINTR 0x040
+#define S6_I2C_CLRRXUNDER 0x044
+#define S6_I2C_CLRRXOVER 0x048
+#define S6_I2C_CLRTXOVER 0x04C
+#define S6_I2C_CLRRDREQ 0x050
+#define S6_I2C_CLRTXABRT 0x054
+#define S6_I2C_CLRRXDONE 0x058
+#define S6_I2C_CLRACTIVITY 0x05C
+#define S6_I2C_CLRSTOPDET 0x060
+#define S6_I2C_CLRSTARTDET 0x064
+#define S6_I2C_CLRGENCALL 0x068
+#define S6_I2C_ENABLE 0x06C
+#define S6_I2C_STATUS 0x070
+#define S6_I2C_STATUS_ACTIVITY 0
+#define S6_I2C_STATUS_TFNF 1
+#define S6_I2C_STATUS_TFE 2
+#define S6_I2C_STATUS_RFNE 3
+#define S6_I2C_STATUS_RFF 4
+#define S6_I2C_TXFLR 0x074
+#define S6_I2C_RXFLR 0x078
+#define S6_I2C_SRESET 0x07C
+#define S6_I2C_SRESET_IC_SRST 0
+#define S6_I2C_SRESET_IC_MASTER_SRST 1
+#define S6_I2C_SRESET_IC_SLAVE_SRST 2
+#define S6_I2C_TXABRTSOURCE 0x080
+
+#endif
diff --git a/include/linux/i2c/s6000.h b/include/linux/i2c/s6000.h
new file mode 100644
index 0000000..0b6b0c6
--- /dev/null
+++ b/include/linux/i2c/s6000.h
@@ -0,0 +1,10 @@
+#ifndef __LINUX_I2C_S6000_H
+#define __LINUX_I2C_S6000_H
+
+struct s6_i2c_platform_data {
+ const char *clock;
+ int bus_num;
+};
+
+#endif
+
--
1.6.2.107.ge47ee


2009-03-23 15:04:35

by Daniel Glöckner

[permalink] [raw]
Subject: [patch 3/5] xtensa: add at24hc02b to s6105 platform

This is particularly used to read the MAC address of the ethernet
controller from an EEPROM.

Signed-off-by: Daniel Glöckner <[email protected]>
---
arch/xtensa/platforms/s6105/device.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/arch/xtensa/platforms/s6105/device.c b/arch/xtensa/platforms/s6105/device.c
index 00f52ee..9394e6f 100644
--- a/arch/xtensa/platforms/s6105/device.c
+++ b/arch/xtensa/platforms/s6105/device.c
@@ -168,6 +168,9 @@ static struct resource s6_i2c_resource[] = {
#define S6I2C_ADDR_PCA9543 0x73

static struct i2c_board_info __initdata s6_i2c_devices[] = {
+ {
+ I2C_BOARD_INFO("24c02", S6I2C_ADDR_AT24HC02B),
+ },
};

static struct platform_device platform_devices[] = {
--
1.6.2.107.ge47ee

2009-03-23 15:04:51

by Daniel Glöckner

[permalink] [raw]
Subject: [patch 2/5] xtensa: s6105 specific configuration for the s6000 i2c host

Signed-off-by: Daniel Glöckner <[email protected]>
Signed-off-by: Oskar Schirmer <[email protected]>
---
arch/xtensa/platforms/s6105/device.c | 51 ++++++++++++++++++++++++++++++++++
1 files changed, 51 insertions(+), 0 deletions(-)

diff --git a/arch/xtensa/platforms/s6105/device.c b/arch/xtensa/platforms/s6105/device.c
index 963634a..00f52ee 100644
--- a/arch/xtensa/platforms/s6105/device.c
+++ b/arch/xtensa/platforms/s6105/device.c
@@ -6,6 +6,8 @@

#include <linux/kernel.h>
#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/i2c/s6000.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/phy.h>
@@ -21,6 +23,7 @@
#define GPIO3_INTNUM 3
#define UART_INTNUM 4
#define GMAC_INTNUM 5
+#define I2C_INTNUM 6

static const signed char gpio3_irq_mappings[] = {
S6_INTC_GPIO(3),
@@ -41,10 +44,16 @@ static const signed char gmac_irq_mappings[] = {
-1
};

+static const signed char i2c_irq_mappings[] = {
+ S6_INTC_I2C,
+ -1
+};
+
const signed char *platform_irq_mappings[NR_IRQS] = {
[GPIO3_INTNUM] = gpio3_irq_mappings,
[UART_INTNUM] = uart_irq_mappings,
[GMAC_INTNUM] = gmac_irq_mappings,
+ [I2C_INTNUM] = i2c_irq_mappings,
};

static struct plat_serial8250_port serial_platform_data[] = {
@@ -129,6 +138,38 @@ fail:
return PHY_POLL;
}

+#define S6_I2C_BUS_NUM 0
+
+static __devinitdata struct s6_i2c_platform_data s6_i2c_pdata = {
+ .bus_num = S6_I2C_BUS_NUM,
+ .clock = "PCLK",
+};
+
+static struct resource s6_i2c_resource[] = {
+ {
+ .name = "mem",
+ .start = (resource_size_t)S6_REG_I2C,
+ .end = (resource_size_t)S6_REG_I2C + 0x1000 - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ {
+ .name = "irq",
+ .start = (resource_size_t)I2C_INTNUM,
+ .flags = IORESOURCE_IRQ,
+ },
+};
+
+#define S6I2C_ADDR_TLV320AIC31 0x18
+#define S6I2C_ADDR_SAA7121 0x44
+#define S6I2C_ADDR_MT9D131 0x48
+#define S6I2C_ADDR_AT24HC02B 0x57
+#define S6I2C_ADDR_M41T62 0x68
+#define S6I2C_ADDR_CDCE906 0x69
+#define S6I2C_ADDR_PCA9543 0x73
+
+static struct i2c_board_info __initdata s6_i2c_devices[] = {
+};
+
static struct platform_device platform_devices[] = {
{
.name = "serial8250",
@@ -143,12 +184,22 @@ static struct platform_device platform_devices[] = {
.resource = s6_gmac_resource,
.num_resources = ARRAY_SIZE(s6_gmac_resource),
},
+ {
+ .name = "i2c-s6000",
+ .resource = s6_i2c_resource,
+ .num_resources = ARRAY_SIZE(s6_i2c_resource),
+ .dev = {
+ .platform_data = &s6_i2c_pdata,
+ },
+ },
};

static int __init device_init(void)
{
int i;

+ i2c_register_board_info(S6_I2C_BUS_NUM, s6_i2c_devices,
+ ARRAY_SIZE(s6_i2c_devices));
s6_gmac_resource[5].start = prepare_phy_irq(GPIO_PHY_IRQ);

for (i = 0; i < ARRAY_SIZE(platform_devices); i++)
--
1.6.2.107.ge47ee

2009-03-23 15:05:12

by Daniel Glöckner

[permalink] [raw]
Subject: [patch 4/5] xtensa: enable s6000 i2c host driver in s6105_defconfig

Signed-off-by: Daniel Glöckner <[email protected]>
---
arch/xtensa/configs/s6105_defconfig | 54 +++++++++++++++++++++++++++++++++-
1 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/configs/s6105_defconfig b/arch/xtensa/configs/s6105_defconfig
index a130c8d..a9a0de9 100644
--- a/arch/xtensa/configs/s6105_defconfig
+++ b/arch/xtensa/configs/s6105_defconfig
@@ -1,7 +1,7 @@
#
# Automatically generated make config: don't edit
# Linux kernel version: 2.6.29-rc7-s6
-# Tue Mar 10 11:09:26 2009
+# Wed Mar 11 13:38:31 2009
#
# CONFIG_FRAME_POINTER is not set
CONFIG_ZONE_DMA=y
@@ -357,7 +357,48 @@ CONFIG_UNIX98_PTYS=y
# CONFIG_R3964 is not set
# CONFIG_RAW_DRIVER is not set
# CONFIG_TCG_TPM is not set
-# CONFIG_I2C is not set
+CONFIG_I2C=y
+CONFIG_I2C_BOARDINFO=y
+# CONFIG_I2C_CHARDEV is not set
+CONFIG_I2C_HELPER_AUTO=y
+
+#
+# I2C Hardware Bus support
+#
+
+#
+# I2C system bus drivers (mostly embedded / system-on-chip)
+#
+# CONFIG_I2C_GPIO is not set
+# CONFIG_I2C_OCORES is not set
+CONFIG_I2C_S6000=y
+# CONFIG_I2C_SIMTEC is not set
+
+#
+# External I2C/SMBus adapter drivers
+#
+# CONFIG_I2C_PARPORT_LIGHT is not set
+# CONFIG_I2C_TAOS_EVM is not set
+
+#
+# Other I2C/SMBus bus drivers
+#
+# CONFIG_I2C_PCA_PLATFORM is not set
+
+#
+# Miscellaneous I2C Chip support
+#
+# CONFIG_DS1682 is not set
+# CONFIG_SENSORS_PCF8574 is not set
+# CONFIG_PCF8575 is not set
+# CONFIG_SENSORS_PCA9539 is not set
+# CONFIG_SENSORS_PCF8591 is not set
+# CONFIG_SENSORS_MAX6875 is not set
+# CONFIG_SENSORS_TSL2550 is not set
+# CONFIG_I2C_DEBUG_CORE is not set
+# CONFIG_I2C_DEBUG_ALGO is not set
+# CONFIG_I2C_DEBUG_BUS is not set
+# CONFIG_I2C_DEBUG_CHIP is not set
# CONFIG_SPI is not set
CONFIG_ARCH_REQUIRE_GPIOLIB=y
CONFIG_GPIOLIB=y
@@ -371,6 +412,9 @@ CONFIG_GPIOLIB=y
#
# I2C GPIO expanders:
#
+# CONFIG_GPIO_MAX732X is not set
+# CONFIG_GPIO_PCA953X is not set
+# CONFIG_GPIO_PCF857X is not set

#
# PCI GPIO expanders:
@@ -398,7 +442,13 @@ CONFIG_SSB_POSSIBLE=y
# CONFIG_MFD_CORE is not set
# CONFIG_MFD_SM501 is not set
# CONFIG_HTC_PASIC3 is not set
+# CONFIG_TPS65010 is not set
+# CONFIG_TWL4030_CORE is not set
# CONFIG_MFD_TMIO is not set
+# CONFIG_PMIC_DA903X is not set
+# CONFIG_MFD_WM8400 is not set
+# CONFIG_MFD_WM8350_I2C is not set
+# CONFIG_MFD_PCF50633 is not set
# CONFIG_REGULATOR is not set

#
--
1.6.2.107.ge47ee

2009-03-23 15:05:54

by Daniel Glöckner

[permalink] [raw]
Subject: [patch 5/5] xtensa: enable at24 driver in s6105_defconfig

Signed-off-by: Daniel Glöckner <[email protected]>
---
arch/xtensa/configs/s6105_defconfig | 12 +++++++++++-
1 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/arch/xtensa/configs/s6105_defconfig b/arch/xtensa/configs/s6105_defconfig
index a9a0de9..e398710 100644
--- a/arch/xtensa/configs/s6105_defconfig
+++ b/arch/xtensa/configs/s6105_defconfig
@@ -251,7 +251,17 @@ CONFIG_BLK_DEV_RAM_SIZE=4096
# CONFIG_CDROM_PKTCDVD is not set
# CONFIG_ATA_OVER_ETH is not set
# CONFIG_BLK_DEV_HD is not set
-# CONFIG_MISC_DEVICES is not set
+CONFIG_MISC_DEVICES=y
+# CONFIG_ICS932S401 is not set
+# CONFIG_ENCLOSURE_SERVICES is not set
+# CONFIG_C2PORT is not set
+
+#
+# EEPROM support
+#
+CONFIG_EEPROM_AT24=y
+# CONFIG_EEPROM_LEGACY is not set
+# CONFIG_EEPROM_93CX6 is not set
CONFIG_HAVE_IDE=y
# CONFIG_IDE is not set

--
1.6.2.107.ge47ee

2009-03-31 22:57:18

by Ben Dooks

[permalink] [raw]
Subject: Re: [patch 1/5] i2c: xtensa s6000 i2c driver

On Mon, Mar 23, 2009 at 04:05:14PM +0100, Daniel Gl??ckner wrote:
> From: Oskar Schirmer <[email protected]>
>
> Support for the s6000 on-chip i2c controller.
>
> Signed-off-by: Oskar Schirmer <[email protected]>
> Signed-off-by: Daniel Gl??ckner <[email protected]>

Not going to merge this on my first pull request to linus, there's
a few things that I'd like to get answered before.

> ---
> drivers/i2c/busses/Kconfig | 10 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-s6000.c | 380 ++++++++++++++++++++++++++++++++++++++++
> drivers/i2c/busses/i2c-s6000.h | 79 +++++++++
> include/linux/i2c/s6000.h | 10 +
> 5 files changed, 480 insertions(+), 0 deletions(-)
> create mode 100644 drivers/i2c/busses/i2c-s6000.c
> create mode 100644 drivers/i2c/busses/i2c-s6000.h
> create mode 100644 include/linux/i2c/s6000.h
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 7f95905..904def4 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -461,6 +461,16 @@ config I2C_S3C2410
> Say Y here to include support for I2C controller in the
> Samsung S3C2410 based System-on-Chip devices.
>
> +config I2C_S6000
> + tristate "S6000 I2C support"
> + depends on XTENSA_VARIANT_S6000
> + help
> + This driver supports the on chip I2C device on the
> + S6000 xtensa processor family.
> +
> + To compile this driver as a module, choose M here. The module
> + will be called i2c-s6000.
> +
> config I2C_SH7760
> tristate "Renesas SH7760 I2C Controller"
> depends on CPU_SUBTYPE_SH7760
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 0c2c4b2..f7989d1 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
> obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
> obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
> obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
> +obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
> obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
> obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
> obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
> diff --git a/drivers/i2c/busses/i2c-s6000.c b/drivers/i2c/busses/i2c-s6000.c
> new file mode 100644
> index 0000000..88e3fdc
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-s6000.c
> @@ -0,0 +1,380 @@
> +/*
> + * drivers/i2c/busses/i2c-s6000.c
> + *
> + * Description: Driver for S6000 Family I2C Interface
> + * (c) 2008 emlix GmbH <[email protected]>

Note, I think you need Copyright here as well, (c) needs to be a
proper c in circle i've been informed.

> + * Author: Oskar Schirmer <[email protected]>
> + *
> + * Partially based on i2c-bfin-twi.c driver by <[email protected]>
> + * Copyright (c) 2005-2007 Analog Devices, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c/s6000.h>
> +#include <linux/timer.h>
> +#include <linux/spinlock.h>
> +#include <linux/completion.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +
> +#include <asm/io.h>
> +#include "i2c-s6000.h"
> +
> +#define POLL_TIMEOUT (2 * HZ)
> +

would be nice to have some documentation for each of the members
of this.

> +struct s6i2c_if {
> + u8 __iomem *reg;
> + int irq;
> + spinlock_t lock;
> + struct i2c_msg *msgs;
> + int msgs_num, msgs_push, msgs_done;
> + unsigned push, done;
> + int timeout_count;
> + struct timer_list timeout_timer;
> + struct i2c_adapter adap;
> + struct completion complete;
> + struct clk *clk;
> + struct resource *res;
> +};
> +
> +#define I2C_RD16(iface, n) readw(iface->reg + (n))
> +#define I2C_WR16(iface, n, v) writew(v, iface->reg + (n))
> +#define I2C_RD32(iface, n) readl(iface->reg + (n))
> +#define I2C_WR32(iface, n, v) writel(v, iface->reg + (n))

tried inline functions for these?

> +
> +static struct s6i2c_if s6i2c_if;
> +
> +static void s6i2c_handle_interrupt(struct s6i2c_if *iface)
> +{
> + if (I2C_RD16(iface, S6_I2C_INTRSTAT) & (1 << S6_I2C_INTR_TXABRT)) {
> + I2C_RD16(iface, S6_I2C_CLRTXABRT);
> + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> + complete(&iface->complete);
> + return;
> + }
> + if (iface->msgs_done >= iface->msgs_num) {
> + printk(KERN_DEBUG "spurious I2C irq: %x\n",
> + I2C_RD16(iface, S6_I2C_INTRSTAT));
> + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> + return;
> + }
> + while ((iface->msgs_push < iface->msgs_num)
> + && (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_TFNF))) {
> + struct i2c_msg *m = &iface->msgs[iface->msgs_push];
> + if (!(m->flags & I2C_M_RD))
> + I2C_WR16(iface, S6_I2C_DATACMD, m->buf[iface->push]);
> + else
> + I2C_WR16(iface, S6_I2C_DATACMD,
> + 1 << S6_I2C_DATACMD_READ);
> + if (++iface->push >= m->len) {
> + iface->push = 0;
> + iface->msgs_push += 1;
> + }
> + }
> + do {
> + struct i2c_msg *m = &iface->msgs[iface->msgs_done];
> + if (!(m->flags & I2C_M_RD)) {
> + if (iface->msgs_done < iface->msgs_push)
> + iface->msgs_done += 1;
> + else
> + break;
> + } else if (I2C_RD16(iface, S6_I2C_STATUS)
> + & (1 << S6_I2C_STATUS_RFNE)) {
> + m->buf[iface->done] = I2C_RD16(iface, S6_I2C_DATACMD);
> + if (++iface->done >= m->len) {
> + iface->done = 0;
> + iface->msgs_done += 1;
> + }
> + } else{
> + break;
> + }
> + } while (iface->msgs_done < iface->msgs_num);
> + if (iface->msgs_done >= iface->msgs_num) {
> + I2C_WR16(iface, S6_I2C_INTRMASK, 1 << S6_I2C_INTR_TXABRT);
> + complete(&iface->complete);
> + } else if (iface->msgs_push >= iface->msgs_num) {
> + I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
> + (1 << S6_I2C_INTR_RXFULL));
> + } else {
> + I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
> + (1 << S6_I2C_INTR_TXEMPTY) |
> + (1 << S6_I2C_INTR_RXFULL));
> + }
> +}
> +
> +static irqreturn_t s6i2c_interrupt_entry(int irq, void *dev_id)
> +{
> + struct s6i2c_if *iface = dev_id;
> + if (!(I2C_RD16(iface, S6_I2C_STATUS) & ((1 << S6_I2C_INTR_RXUNDER)
> + | (1 << S6_I2C_INTR_RXOVER)
> + | (1 << S6_I2C_INTR_RXFULL)
> + | (1 << S6_I2C_INTR_TXOVER)
> + | (1 << S6_I2C_INTR_TXEMPTY)
> + | (1 << S6_I2C_INTR_RDREQ)
> + | (1 << S6_I2C_INTR_TXABRT)
> + | (1 << S6_I2C_INTR_RXDONE)
> + | (1 << S6_I2C_INTR_ACTIVITY)
> + | (1 << S6_I2C_INTR_STOPDET)
> + | (1 << S6_I2C_INTR_STARTDET)
> + | (1 << S6_I2C_INTR_GENCALL))))
> + return IRQ_NONE;
> +
> + spin_lock(&iface->lock);
> + del_timer(&iface->timeout_timer);
> + s6i2c_handle_interrupt(iface);
> + spin_unlock(&iface->lock);
> + return IRQ_HANDLED;
> +}
> +
> +static void s6i2c_timeout(unsigned long data)
> +{
> + struct s6i2c_if *iface = (struct s6i2c_if *)data;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&iface->lock, flags);
> + s6i2c_handle_interrupt(iface);
> + if (--iface->timeout_count > 0) {
> + iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
> + add_timer(&iface->timeout_timer);
> + } else {
> + complete(&iface->complete);
> + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> + }
> + spin_unlock_irqrestore(&iface->lock, flags);
> +}
> +
> +static int s6i2c_master_xfer(struct i2c_adapter *adap,
> + struct i2c_msg *msgs, int num)
> +{
> + struct s6i2c_if *iface = adap->algo_data;
> + int i;
> + if (num == 0)
> + return 0;
> + if (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
> + yield();
> + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> + I2C_RD16(iface, S6_I2C_CLRINTR);
> + for (i = 0; i < num; i++) {
> + if (msgs[i].flags & I2C_M_TEN) {
> + dev_err(&(adap->dev),
> + "s6i2c: 10 bits addr not supported\n");
> + return -EINVAL;
> + }
> + if (msgs[i].len == 0) {
> + dev_err(&(adap->dev),
> + "s6i2c: zero length message not supported\n");
> + return -EINVAL;
> + }
> + if (msgs[i].addr != msgs[0].addr) {
> + dev_err(&(adap->dev),
> + "s6i2c: multiple xfer cannot change target\n");
> + return -EINVAL;
> + }
> + }
> + iface->msgs = msgs;
> + iface->msgs_num = num;
> + iface->msgs_push = 0;
> + iface->msgs_done = 0;
> + iface->push = 0;
> + iface->done = 0;
> + iface->timeout_count = 10;
> + I2C_WR16(iface, S6_I2C_TAR, msgs[0].addr);
> + I2C_WR16(iface, S6_I2C_ENABLE, 1);
> + I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXEMPTY) |
> + (1 << S6_I2C_INTR_TXABRT));
> + iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
> + add_timer(&iface->timeout_timer);
> + wait_for_completion(&iface->complete);
> + del_timer_sync(&iface->timeout_timer);
> + while (I2C_RD32(iface, S6_I2C_TXFLR) > 0)
> + schedule();
> + while (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
> + schedule();
> + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> + I2C_WR16(iface, S6_I2C_ENABLE, 0);
> + return iface->msgs_done;
> +}
> +
> +static u32 s6i2c_functionality(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> +}
> +
> +static struct i2c_algorithm s6i2c_algorithm = {
> + .master_xfer = s6i2c_master_xfer,
> + .functionality = s6i2c_functionality,
> +};
> +
> +static u16 __devinit nanoseconds_on_clk(struct s6i2c_if *iface, u32 ns)
> +{
> + u64 dividend = (u64)ns * clk_get_rate(iface->clk);
> + do_div(dividend, 1000000000);
> + if (dividend > 0xffff)
> + return 0xffff;
> + return dividend;
> +}

do you desperately need to be _that_ accurate?

> +static int __devinit s6i2c_probe(struct platform_device *dev)
> +{
> + struct s6i2c_if *iface = &s6i2c_if;
> + struct i2c_adapter *p_adap;
> + const char *clock;
> + int bus_num, rc;
> + spin_lock_init(&(iface->lock));
> + init_completion(&(iface->complete));

please don't do &(variable) it is fugly.

> + iface->irq = platform_get_irq(dev, 0);
> + if (iface->irq < 0) {
> + rc = iface->irq;
> + goto err_out;
> + }
> + iface->res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> + if (!iface->res) {
> + rc = -ENXIO;
> + goto err_out;
> + }
> + iface->res = request_mem_region(iface->res->start,
> + iface->res->end - iface->res->start + 1,
> + dev->dev.bus_id);
> + if (!iface->res) {
> + rc = -EBUSY;
> + goto err_out;
> + }
> + iface->reg = ioremap_nocache(iface->res->start,
> + iface->res->end - iface->res->start + 1);
> + if (!iface->reg) {
> + rc = -ENOMEM;
> + goto err_reg;
> + }
> + clock = 0;
> + bus_num = -1;
> + if (dev->dev.platform_data) {
> + struct s6_i2c_platform_data *pdata = dev->dev.platform_data;
> + bus_num = pdata->bus_num;
> + clock = pdata->clock;
> + }
> + iface->clk = clk_get(&dev->dev, clock);
> + if (IS_ERR(iface->clk)) {
> + rc = PTR_ERR(iface->clk);
> + goto err_map;
> + }

passing the name in the platform device is a bit nasty, if there's
only one clock for the device then it should have been dealt with
at the arch level and doing clk_get(&dev->dev, NULL) should be
acceptable.

> + rc = clk_enable(iface->clk);
> + if (rc < 0)
> + goto err_clk_put;
> + init_timer(&(iface->timeout_timer));
> + iface->timeout_timer.function = s6i2c_timeout;
> + iface->timeout_timer.data = (unsigned long)iface;
> + p_adap = &iface->adap;
> + strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
> + p_adap->algo = &s6i2c_algorithm;
> + p_adap->algo_data = iface;
> + p_adap->nr = bus_num;
> + p_adap->class = 0;
> + p_adap->dev.parent = &dev->dev;

some spacing for readability would be nice.

> + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> + rc = request_irq(iface->irq, s6i2c_interrupt_entry,
> + IRQF_SHARED, dev->name, iface);
> + if (rc) {
> + dev_err(&(p_adap->dev), "s6i2c: cant get IRQ %d\n", iface->irq);
> + goto err_clk_dis;
> + }
> + I2C_WR16(iface, S6_I2C_ENABLE, 0);
> + udelay(1);
> + I2C_WR32(iface, S6_I2C_SRESET, 1 << S6_I2C_SRESET_IC_SRST);
> + I2C_WR16(iface, S6_I2C_CLRTXABRT, 1);
> + I2C_WR16(iface, S6_I2C_CON,
> + (1 << S6_I2C_CON_MASTER) |
> + (S6_I2C_CON_SPEED_NORMAL << S6_I2C_CON_SPEED) |
> + (0 << S6_I2C_CON_10BITSLAVE) |
> + (0 << S6_I2C_CON_10BITMASTER) |
> + (1 << S6_I2C_CON_RESTARTENA) |
> + (1 << S6_I2C_CON_SLAVEDISABLE));
> + I2C_WR16(iface, S6_I2C_SSHCNT, nanoseconds_on_clk(iface, 4000));
> + I2C_WR16(iface, S6_I2C_SSLCNT, nanoseconds_on_clk(iface, 4700));
> + I2C_WR16(iface, S6_I2C_FSHCNT, nanoseconds_on_clk(iface, 600));
> + I2C_WR16(iface, S6_I2C_FSLCNT, nanoseconds_on_clk(iface, 1300));
> + I2C_WR16(iface, S6_I2C_RXTL, 0);
> + I2C_WR16(iface, S6_I2C_TXTL, 0);
> + platform_set_drvdata(dev, iface);
> + if (bus_num < 0)
> + rc = i2c_add_adapter(p_adap);
> + else
> + rc = i2c_add_numbered_adapter(p_adap);
> + if (rc)
> + goto err_irq_free;
> + return 0;
> +
> +err_irq_free:
> + free_irq(iface->irq, iface);
> +err_clk_dis:
> + clk_disable(iface->clk);
> +err_clk_put:
> + clk_put(iface->clk);
> +err_map:
> + iounmap(iface->reg);
> +err_reg:
> + release_mem_region(iface->res->start,
> + iface->res->end - iface->res->start + 1);
> +err_out:
> + return rc;
> +}
> +
> +static int __devexit s6i2c_remove(struct platform_device *pdev)
> +{
> + struct s6i2c_if *iface = platform_get_drvdata(pdev);
> + I2C_WR16(iface, S6_I2C_ENABLE, 0);
> + platform_set_drvdata(pdev, NULL);
> + i2c_del_adapter(&(iface->adap));
> + free_irq(iface->irq, iface);
> + clk_disable(iface->clk);
> + clk_put(iface->clk);
> + iounmap(iface->reg);
> + release_mem_region(iface->res->start,
> + iface->res->end - iface->res->start + 1);

resource_size() would be good here, and elsewhere in the driver.

> + return 0;
> +}
> +
> +static struct platform_driver s6i2c_driver = {
> + .probe = s6i2c_probe,
> + .remove = __devexit_p(s6i2c_remove),
> + .driver = {
> + .name = "i2c-s6000",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +static int __init s6i2c_init(void)
> +{
> + pr_info("I2C: S6000 I2C driver\n");
> + return platform_driver_register(&s6i2c_driver);
> +}
> +
> +static void __exit s6i2c_exit(void)
> +{
> + platform_driver_unregister(&s6i2c_driver);
> +}
> +
> +MODULE_DESCRIPTION("I2C-Bus adapter routines for S6000 I2C");
> +MODULE_LICENSE("GPL");
> +
> +subsys_initcall(s6i2c_init);
> +module_exit(s6i2c_exit);


as a note, the code is quite dense, a few blank lines would be
nice.

> diff --git a/drivers/i2c/busses/i2c-s6000.h b/drivers/i2c/busses/i2c-s6000.h
> new file mode 100644
> index 0000000..ff23b81
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-s6000.h
> @@ -0,0 +1,79 @@
> +/*
> + * drivers/i2c/busses/i2c-s6000.h
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License. See the file "COPYING" in the main directory of this archive
> + * for more details.
> + *
> + * Copyright (C) 2008 Emlix GmbH <[email protected]>
> + * Author: Oskar Schirmer <[email protected]>
> + */
> +
> +#ifndef __DRIVERS_I2C_BUSSES_I2C_S6000_H
> +#define __DRIVERS_I2C_BUSSES_I2C_S6000_H
> +
> +#define S6_I2C_CON 0x000
> +#define S6_I2C_CON_MASTER 0
> +#define S6_I2C_CON_SPEED 1
> +#define S6_I2C_CON_SPEED_NORMAL 1
> +#define S6_I2C_CON_SPEED_FAST 2
> +#define S6_I2C_CON_SPEED_MASK 3
> +#define S6_I2C_CON_10BITSLAVE 3
> +#define S6_I2C_CON_10BITMASTER 4
> +#define S6_I2C_CON_RESTARTENA 5
> +#define S6_I2C_CON_SLAVEDISABLE 6
> +#define S6_I2C_TAR 0x004
> +#define S6_I2C_TAR_GCORSTART 10
> +#define S6_I2C_TAR_SPECIAL 11
> +#define S6_I2C_SAR 0x008
> +#define S6_I2C_HSMADDR 0x00C
> +#define S6_I2C_DATACMD 0x010
> +#define S6_I2C_DATACMD_READ 8
> +#define S6_I2C_SSHCNT 0x014
> +#define S6_I2C_SSLCNT 0x018
> +#define S6_I2C_FSHCNT 0x01C
> +#define S6_I2C_FSLCNT 0x020
> +#define S6_I2C_INTRSTAT 0x02C
> +#define S6_I2C_INTRMASK 0x030
> +#define S6_I2C_RAWINTR 0x034
> +#define S6_I2C_INTR_RXUNDER 0
> +#define S6_I2C_INTR_RXOVER 1
> +#define S6_I2C_INTR_RXFULL 2
> +#define S6_I2C_INTR_TXOVER 3
> +#define S6_I2C_INTR_TXEMPTY 4
> +#define S6_I2C_INTR_RDREQ 5
> +#define S6_I2C_INTR_TXABRT 6
> +#define S6_I2C_INTR_RXDONE 7
> +#define S6_I2C_INTR_ACTIVITY 8
> +#define S6_I2C_INTR_STOPDET 9
> +#define S6_I2C_INTR_STARTDET 10
> +#define S6_I2C_INTR_GENCALL 11
> +#define S6_I2C_RXTL 0x038
> +#define S6_I2C_TXTL 0x03C
> +#define S6_I2C_CLRINTR 0x040
> +#define S6_I2C_CLRRXUNDER 0x044
> +#define S6_I2C_CLRRXOVER 0x048
> +#define S6_I2C_CLRTXOVER 0x04C
> +#define S6_I2C_CLRRDREQ 0x050
> +#define S6_I2C_CLRTXABRT 0x054
> +#define S6_I2C_CLRRXDONE 0x058
> +#define S6_I2C_CLRACTIVITY 0x05C
> +#define S6_I2C_CLRSTOPDET 0x060
> +#define S6_I2C_CLRSTARTDET 0x064
> +#define S6_I2C_CLRGENCALL 0x068
> +#define S6_I2C_ENABLE 0x06C
> +#define S6_I2C_STATUS 0x070
> +#define S6_I2C_STATUS_ACTIVITY 0
> +#define S6_I2C_STATUS_TFNF 1
> +#define S6_I2C_STATUS_TFE 2
> +#define S6_I2C_STATUS_RFNE 3
> +#define S6_I2C_STATUS_RFF 4
> +#define S6_I2C_TXFLR 0x074
> +#define S6_I2C_RXFLR 0x078
> +#define S6_I2C_SRESET 0x07C
> +#define S6_I2C_SRESET_IC_SRST 0
> +#define S6_I2C_SRESET_IC_MASTER_SRST 1
> +#define S6_I2C_SRESET_IC_SLAVE_SRST 2
> +#define S6_I2C_TXABRTSOURCE 0x080
> +
> +#endif
> diff --git a/include/linux/i2c/s6000.h b/include/linux/i2c/s6000.h

and again.

> new file mode 100644
> index 0000000..0b6b0c6
> --- /dev/null
> +++ b/include/linux/i2c/s6000.h
> @@ -0,0 +1,10 @@
> +#ifndef __LINUX_I2C_S6000_H
> +#define __LINUX_I2C_S6000_H
> +

documentation comments would be nice here too.

> +struct s6_i2c_platform_data {
> + const char *clock;
> + int bus_num;
> +};
> +
> +#endif
> +
> --
> 1.6.2.107.ge47ee
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Ben ([email protected], http://www.fluff.org/)

'a smiley only costs 4 bytes'

2009-03-31 23:01:55

by Ben Dooks

[permalink] [raw]
Subject: Re: [patch 1/5] i2c: xtensa s6000 i2c driver

On Tue, Mar 31, 2009 at 11:52:58PM +0100, Ben Dooks wrote:
> On Mon, Mar 23, 2009 at 04:05:14PM +0100, Daniel Gl??ckner wrote:
> > From: Oskar Schirmer <[email protected]>
> >
> > Support for the s6000 on-chip i2c controller.
> >
> > Signed-off-by: Oskar Schirmer <[email protected]>
> > Signed-off-by: Daniel Gl??ckner <[email protected]>
>
> Not going to merge this on my first pull request to linus, there's
> a few things that I'd like to get answered before.

and a few other things i've just noticed:

> > ---
> > drivers/i2c/busses/Kconfig | 10 +
> > drivers/i2c/busses/Makefile | 1 +
> > drivers/i2c/busses/i2c-s6000.c | 380 ++++++++++++++++++++++++++++++++++++++++
> > drivers/i2c/busses/i2c-s6000.h | 79 +++++++++
> > include/linux/i2c/s6000.h | 10 +
> > 5 files changed, 480 insertions(+), 0 deletions(-)
> > create mode 100644 drivers/i2c/busses/i2c-s6000.c
> > create mode 100644 drivers/i2c/busses/i2c-s6000.h
> > create mode 100644 include/linux/i2c/s6000.h
> >
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index 7f95905..904def4 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -461,6 +461,16 @@ config I2C_S3C2410
> > Say Y here to include support for I2C controller in the
> > Samsung S3C2410 based System-on-Chip devices.
> >
> > +config I2C_S6000
> > + tristate "S6000 I2C support"
> > + depends on XTENSA_VARIANT_S6000
> > + help
> > + This driver supports the on chip I2C device on the
> > + S6000 xtensa processor family.
> > +
> > + To compile this driver as a module, choose M here. The module
> > + will be called i2c-s6000.
> > +
> > config I2C_SH7760
> > tristate "Renesas SH7760 I2C Controller"
> > depends on CPU_SUBTYPE_SH7760
> > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> > index 0c2c4b2..f7989d1 100644
> > --- a/drivers/i2c/busses/Makefile
> > +++ b/drivers/i2c/busses/Makefile
> > @@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
> > obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
> > obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
> > obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
> > +obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
> > obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
> > obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
> > obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
> > diff --git a/drivers/i2c/busses/i2c-s6000.c b/drivers/i2c/busses/i2c-s6000.c
> > new file mode 100644
> > index 0000000..88e3fdc
> > --- /dev/null
> > +++ b/drivers/i2c/busses/i2c-s6000.c
> > @@ -0,0 +1,380 @@
> > +/*
> > + * drivers/i2c/busses/i2c-s6000.c
> > + *
> > + * Description: Driver for S6000 Family I2C Interface
> > + * (c) 2008 emlix GmbH <[email protected]>
>
> Note, I think you need Copyright here as well, (c) needs to be a
> proper c in circle i've been informed.
>
> > + * Author: Oskar Schirmer <[email protected]>
> > + *
> > + * Partially based on i2c-bfin-twi.c driver by <[email protected]>
> > + * Copyright (c) 2005-2007 Analog Devices, Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program; if not, write to the Free Software
> > + * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/err.h>
> > +#include <linux/module.h>
> > +#include <linux/kernel.h>
> > +#include <linux/init.h>
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/i2c/s6000.h>
> > +#include <linux/timer.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/completion.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +
> > +#include <asm/io.h>
> > +#include "i2c-s6000.h"
> > +
> > +#define POLL_TIMEOUT (2 * HZ)
> > +
>
> would be nice to have some documentation for each of the members
> of this.
>
> > +struct s6i2c_if {
> > + u8 __iomem *reg;
> > + int irq;
> > + spinlock_t lock;
> > + struct i2c_msg *msgs;
> > + int msgs_num, msgs_push, msgs_done;
> > + unsigned push, done;
> > + int timeout_count;
> > + struct timer_list timeout_timer;
> > + struct i2c_adapter adap;
> > + struct completion complete;
> > + struct clk *clk;
> > + struct resource *res;
> > +};
> > +
> > +#define I2C_RD16(iface, n) readw(iface->reg + (n))
> > +#define I2C_WR16(iface, n, v) writew(v, iface->reg + (n))
> > +#define I2C_RD32(iface, n) readl(iface->reg + (n))
> > +#define I2C_WR32(iface, n, v) writel(v, iface->reg + (n))
>
> tried inline functions for these?
>
> > +
> > +static struct s6i2c_if s6i2c_if;
> > +
> > +static void s6i2c_handle_interrupt(struct s6i2c_if *iface)
> > +{
> > + if (I2C_RD16(iface, S6_I2C_INTRSTAT) & (1 << S6_I2C_INTR_TXABRT)) {
> > + I2C_RD16(iface, S6_I2C_CLRTXABRT);
> > + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> > + complete(&iface->complete);
> > + return;
> > + }
> > + if (iface->msgs_done >= iface->msgs_num) {
> > + printk(KERN_DEBUG "spurious I2C irq: %x\n",
> > + I2C_RD16(iface, S6_I2C_INTRSTAT));

storing the device and using dev_ functions would be much better.

> > + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> > + return;
> > + }
> > + while ((iface->msgs_push < iface->msgs_num)
> > + && (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_TFNF))) {
> > + struct i2c_msg *m = &iface->msgs[iface->msgs_push];
> > + if (!(m->flags & I2C_M_RD))
> > + I2C_WR16(iface, S6_I2C_DATACMD, m->buf[iface->push]);
> > + else
> > + I2C_WR16(iface, S6_I2C_DATACMD,
> > + 1 << S6_I2C_DATACMD_READ);
> > + if (++iface->push >= m->len) {
> > + iface->push = 0;
> > + iface->msgs_push += 1;
> > + }
> > + }
> > + do {
> > + struct i2c_msg *m = &iface->msgs[iface->msgs_done];
> > + if (!(m->flags & I2C_M_RD)) {
> > + if (iface->msgs_done < iface->msgs_push)
> > + iface->msgs_done += 1;
> > + else
> > + break;
> > + } else if (I2C_RD16(iface, S6_I2C_STATUS)
> > + & (1 << S6_I2C_STATUS_RFNE)) {
> > + m->buf[iface->done] = I2C_RD16(iface, S6_I2C_DATACMD);
> > + if (++iface->done >= m->len) {
> > + iface->done = 0;
> > + iface->msgs_done += 1;
> > + }
> > + } else{
> > + break;
> > + }
> > + } while (iface->msgs_done < iface->msgs_num);
> > + if (iface->msgs_done >= iface->msgs_num) {
> > + I2C_WR16(iface, S6_I2C_INTRMASK, 1 << S6_I2C_INTR_TXABRT);
> > + complete(&iface->complete);
> > + } else if (iface->msgs_push >= iface->msgs_num) {
> > + I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
> > + (1 << S6_I2C_INTR_RXFULL));
> > + } else {
> > + I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
> > + (1 << S6_I2C_INTR_TXEMPTY) |
> > + (1 << S6_I2C_INTR_RXFULL));
> > + }
> > +}
> > +
> > +static irqreturn_t s6i2c_interrupt_entry(int irq, void *dev_id)
> > +{
> > + struct s6i2c_if *iface = dev_id;
> > + if (!(I2C_RD16(iface, S6_I2C_STATUS) & ((1 << S6_I2C_INTR_RXUNDER)
> > + | (1 << S6_I2C_INTR_RXOVER)
> > + | (1 << S6_I2C_INTR_RXFULL)
> > + | (1 << S6_I2C_INTR_TXOVER)
> > + | (1 << S6_I2C_INTR_TXEMPTY)
> > + | (1 << S6_I2C_INTR_RDREQ)
> > + | (1 << S6_I2C_INTR_TXABRT)
> > + | (1 << S6_I2C_INTR_RXDONE)
> > + | (1 << S6_I2C_INTR_ACTIVITY)
> > + | (1 << S6_I2C_INTR_STOPDET)
> > + | (1 << S6_I2C_INTR_STARTDET)
> > + | (1 << S6_I2C_INTR_GENCALL))))
> > + return IRQ_NONE;
> > +
> > + spin_lock(&iface->lock);
> > + del_timer(&iface->timeout_timer);
> > + s6i2c_handle_interrupt(iface);
> > + spin_unlock(&iface->lock);
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static void s6i2c_timeout(unsigned long data)
> > +{
> > + struct s6i2c_if *iface = (struct s6i2c_if *)data;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&iface->lock, flags);
> > + s6i2c_handle_interrupt(iface);
> > + if (--iface->timeout_count > 0) {
> > + iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
> > + add_timer(&iface->timeout_timer);
> > + } else {
> > + complete(&iface->complete);
> > + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> > + }
> > + spin_unlock_irqrestore(&iface->lock, flags);
> > +}
> > +
> > +static int s6i2c_master_xfer(struct i2c_adapter *adap,
> > + struct i2c_msg *msgs, int num)
> > +{
> > + struct s6i2c_if *iface = adap->algo_data;
> > + int i;
> > + if (num == 0)
> > + return 0;
> > + if (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
> > + yield();
> > + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> > + I2C_RD16(iface, S6_I2C_CLRINTR);
> > + for (i = 0; i < num; i++) {
> > + if (msgs[i].flags & I2C_M_TEN) {
> > + dev_err(&(adap->dev),
> > + "s6i2c: 10 bits addr not supported\n");
> > + return -EINVAL;
> > + }
> > + if (msgs[i].len == 0) {
> > + dev_err(&(adap->dev),
> > + "s6i2c: zero length message not supported\n");
> > + return -EINVAL;
> > + }
> > + if (msgs[i].addr != msgs[0].addr) {
> > + dev_err(&(adap->dev),
> > + "s6i2c: multiple xfer cannot change target\n");
> > + return -EINVAL;
> > + }
> > + }
> > + iface->msgs = msgs;
> > + iface->msgs_num = num;
> > + iface->msgs_push = 0;
> > + iface->msgs_done = 0;
> > + iface->push = 0;
> > + iface->done = 0;
> > + iface->timeout_count = 10;
> > + I2C_WR16(iface, S6_I2C_TAR, msgs[0].addr);
> > + I2C_WR16(iface, S6_I2C_ENABLE, 1);
> > + I2C_WR16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXEMPTY) |
> > + (1 << S6_I2C_INTR_TXABRT));
> > + iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
> > + add_timer(&iface->timeout_timer);
> > + wait_for_completion(&iface->complete);
> > + del_timer_sync(&iface->timeout_timer);
> > + while (I2C_RD32(iface, S6_I2C_TXFLR) > 0)
> > + schedule();
> > + while (I2C_RD16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
> > + schedule();
> > + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> > + I2C_WR16(iface, S6_I2C_ENABLE, 0);
> > + return iface->msgs_done;
> > +}
> > +
> > +static u32 s6i2c_functionality(struct i2c_adapter *adap)
> > +{
> > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> > +}
> > +
> > +static struct i2c_algorithm s6i2c_algorithm = {
> > + .master_xfer = s6i2c_master_xfer,
> > + .functionality = s6i2c_functionality,
> > +};
> > +
> > +static u16 __devinit nanoseconds_on_clk(struct s6i2c_if *iface, u32 ns)
> > +{
> > + u64 dividend = (u64)ns * clk_get_rate(iface->clk);
> > + do_div(dividend, 1000000000);
> > + if (dividend > 0xffff)
> > + return 0xffff;
> > + return dividend;
> > +}
>
> do you desperately need to be _that_ accurate?
>
> > +static int __devinit s6i2c_probe(struct platform_device *dev)
> > +{
> > + struct s6i2c_if *iface = &s6i2c_if;
> > + struct i2c_adapter *p_adap;
> > + const char *clock;
> > + int bus_num, rc;
> > + spin_lock_init(&(iface->lock));
> > + init_completion(&(iface->complete));
>
> please don't do &(variable) it is fugly.
>
> > + iface->irq = platform_get_irq(dev, 0);
> > + if (iface->irq < 0) {
> > + rc = iface->irq;
> > + goto err_out;
> > + }
> > + iface->res = platform_get_resource(dev, IORESOURCE_MEM, 0);
> > + if (!iface->res) {
> > + rc = -ENXIO;
> > + goto err_out;
> > + }
> > + iface->res = request_mem_region(iface->res->start,
> > + iface->res->end - iface->res->start + 1,
> > + dev->dev.bus_id);

resource_size() is your friend here too, and in various others bits
of the code.

> > + if (!iface->res) {
> > + rc = -EBUSY;
> > + goto err_out;
> > + }
> > + iface->reg = ioremap_nocache(iface->res->start,
> > + iface->res->end - iface->res->start + 1);
> > + if (!iface->reg) {
> > + rc = -ENOMEM;
> > + goto err_reg;
> > + }
> > + clock = 0;
> > + bus_num = -1;
> > + if (dev->dev.platform_data) {
> > + struct s6_i2c_platform_data *pdata = dev->dev.platform_data;
> > + bus_num = pdata->bus_num;
> > + clock = pdata->clock;
> > + }
> > + iface->clk = clk_get(&dev->dev, clock);
> > + if (IS_ERR(iface->clk)) {
> > + rc = PTR_ERR(iface->clk);
> > + goto err_map;
> > + }
>
> passing the name in the platform device is a bit nasty, if there's
> only one clock for the device then it should have been dealt with
> at the arch level and doing clk_get(&dev->dev, NULL) should be
> acceptable.
>
> > + rc = clk_enable(iface->clk);
> > + if (rc < 0)
> > + goto err_clk_put;
> > + init_timer(&(iface->timeout_timer));
> > + iface->timeout_timer.function = s6i2c_timeout;
> > + iface->timeout_timer.data = (unsigned long)iface;
> > + p_adap = &iface->adap;
> > + strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
> > + p_adap->algo = &s6i2c_algorithm;
> > + p_adap->algo_data = iface;
> > + p_adap->nr = bus_num;
> > + p_adap->class = 0;
> > + p_adap->dev.parent = &dev->dev;
>
> some spacing for readability would be nice.
>
> > + I2C_WR16(iface, S6_I2C_INTRMASK, 0);
> > + rc = request_irq(iface->irq, s6i2c_interrupt_entry,
> > + IRQF_SHARED, dev->name, iface);
> > + if (rc) {
> > + dev_err(&(p_adap->dev), "s6i2c: cant get IRQ %d\n", iface->irq);
> > + goto err_clk_dis;
> > + }
> > + I2C_WR16(iface, S6_I2C_ENABLE, 0);
> > + udelay(1);
> > + I2C_WR32(iface, S6_I2C_SRESET, 1 << S6_I2C_SRESET_IC_SRST);
> > + I2C_WR16(iface, S6_I2C_CLRTXABRT, 1);
> > + I2C_WR16(iface, S6_I2C_CON,
> > + (1 << S6_I2C_CON_MASTER) |
> > + (S6_I2C_CON_SPEED_NORMAL << S6_I2C_CON_SPEED) |
> > + (0 << S6_I2C_CON_10BITSLAVE) |
> > + (0 << S6_I2C_CON_10BITMASTER) |
> > + (1 << S6_I2C_CON_RESTARTENA) |
> > + (1 << S6_I2C_CON_SLAVEDISABLE));
> > + I2C_WR16(iface, S6_I2C_SSHCNT, nanoseconds_on_clk(iface, 4000));
> > + I2C_WR16(iface, S6_I2C_SSLCNT, nanoseconds_on_clk(iface, 4700));
> > + I2C_WR16(iface, S6_I2C_FSHCNT, nanoseconds_on_clk(iface, 600));
> > + I2C_WR16(iface, S6_I2C_FSLCNT, nanoseconds_on_clk(iface, 1300));
> > + I2C_WR16(iface, S6_I2C_RXTL, 0);
> > + I2C_WR16(iface, S6_I2C_TXTL, 0);
> > + platform_set_drvdata(dev, iface);
> > + if (bus_num < 0)
> > + rc = i2c_add_adapter(p_adap);
> > + else
> > + rc = i2c_add_numbered_adapter(p_adap);
> > + if (rc)
> > + goto err_irq_free;
> > + return 0;
> > +
> > +err_irq_free:
> > + free_irq(iface->irq, iface);
> > +err_clk_dis:
> > + clk_disable(iface->clk);
> > +err_clk_put:
> > + clk_put(iface->clk);
> > +err_map:
> > + iounmap(iface->reg);
> > +err_reg:
> > + release_mem_region(iface->res->start,
> > + iface->res->end - iface->res->start + 1);
> > +err_out:
> > + return rc;
> > +}
> > +
> > +static int __devexit s6i2c_remove(struct platform_device *pdev)
> > +{
> > + struct s6i2c_if *iface = platform_get_drvdata(pdev);
> > + I2C_WR16(iface, S6_I2C_ENABLE, 0);
> > + platform_set_drvdata(pdev, NULL);
> > + i2c_del_adapter(&(iface->adap));
> > + free_irq(iface->irq, iface);
> > + clk_disable(iface->clk);
> > + clk_put(iface->clk);
> > + iounmap(iface->reg);
> > + release_mem_region(iface->res->start,
> > + iface->res->end - iface->res->start + 1);
>
> resource_size() would be good here, and elsewhere in the driver.
>
> > + return 0;
> > +}
> > +
> > +static struct platform_driver s6i2c_driver = {
> > + .probe = s6i2c_probe,
> > + .remove = __devexit_p(s6i2c_remove),
> > + .driver = {
> > + .name = "i2c-s6000",
> > + .owner = THIS_MODULE,
> > + },
> > +};
> > +
> > +static int __init s6i2c_init(void)
> > +{
> > + pr_info("I2C: S6000 I2C driver\n");
> > + return platform_driver_register(&s6i2c_driver);
> > +}
> > +
> > +static void __exit s6i2c_exit(void)
> > +{
> > + platform_driver_unregister(&s6i2c_driver);
> > +}
> > +
> > +MODULE_DESCRIPTION("I2C-Bus adapter routines for S6000 I2C");
> > +MODULE_LICENSE("GPL");

alias for module loading would also be useful.

> > +
> > +subsys_initcall(s6i2c_init);
> > +module_exit(s6i2c_exit);


> as a note, the code is quite dense, a few blank lines would be
> nice.
>
> > diff --git a/drivers/i2c/busses/i2c-s6000.h b/drivers/i2c/busses/i2c-s6000.h
> > new file mode 100644
> > index 0000000..ff23b81
> > --- /dev/null
> > +++ b/drivers/i2c/busses/i2c-s6000.h
> > @@ -0,0 +1,79 @@
> > +/*
> > + * drivers/i2c/busses/i2c-s6000.h
> > + *
> > + * This file is subject to the terms and conditions of the GNU General Public
> > + * License. See the file "COPYING" in the main directory of this archive
> > + * for more details.
> > + *
> > + * Copyright (C) 2008 Emlix GmbH <[email protected]>
> > + * Author: Oskar Schirmer <[email protected]>
> > + */
> > +
> > +#ifndef __DRIVERS_I2C_BUSSES_I2C_S6000_H
> > +#define __DRIVERS_I2C_BUSSES_I2C_S6000_H
> > +
> > +#define S6_I2C_CON 0x000
> > +#define S6_I2C_CON_MASTER 0
> > +#define S6_I2C_CON_SPEED 1
> > +#define S6_I2C_CON_SPEED_NORMAL 1
> > +#define S6_I2C_CON_SPEED_FAST 2
> > +#define S6_I2C_CON_SPEED_MASK 3
> > +#define S6_I2C_CON_10BITSLAVE 3
> > +#define S6_I2C_CON_10BITMASTER 4
> > +#define S6_I2C_CON_RESTARTENA 5
> > +#define S6_I2C_CON_SLAVEDISABLE 6
> > +#define S6_I2C_TAR 0x004
> > +#define S6_I2C_TAR_GCORSTART 10
> > +#define S6_I2C_TAR_SPECIAL 11
> > +#define S6_I2C_SAR 0x008
> > +#define S6_I2C_HSMADDR 0x00C
> > +#define S6_I2C_DATACMD 0x010
> > +#define S6_I2C_DATACMD_READ 8
> > +#define S6_I2C_SSHCNT 0x014
> > +#define S6_I2C_SSLCNT 0x018
> > +#define S6_I2C_FSHCNT 0x01C
> > +#define S6_I2C_FSLCNT 0x020
> > +#define S6_I2C_INTRSTAT 0x02C
> > +#define S6_I2C_INTRMASK 0x030
> > +#define S6_I2C_RAWINTR 0x034
> > +#define S6_I2C_INTR_RXUNDER 0
> > +#define S6_I2C_INTR_RXOVER 1
> > +#define S6_I2C_INTR_RXFULL 2
> > +#define S6_I2C_INTR_TXOVER 3
> > +#define S6_I2C_INTR_TXEMPTY 4
> > +#define S6_I2C_INTR_RDREQ 5
> > +#define S6_I2C_INTR_TXABRT 6
> > +#define S6_I2C_INTR_RXDONE 7
> > +#define S6_I2C_INTR_ACTIVITY 8
> > +#define S6_I2C_INTR_STOPDET 9
> > +#define S6_I2C_INTR_STARTDET 10
> > +#define S6_I2C_INTR_GENCALL 11
> > +#define S6_I2C_RXTL 0x038
> > +#define S6_I2C_TXTL 0x03C
> > +#define S6_I2C_CLRINTR 0x040
> > +#define S6_I2C_CLRRXUNDER 0x044
> > +#define S6_I2C_CLRRXOVER 0x048
> > +#define S6_I2C_CLRTXOVER 0x04C
> > +#define S6_I2C_CLRRDREQ 0x050
> > +#define S6_I2C_CLRTXABRT 0x054
> > +#define S6_I2C_CLRRXDONE 0x058
> > +#define S6_I2C_CLRACTIVITY 0x05C
> > +#define S6_I2C_CLRSTOPDET 0x060
> > +#define S6_I2C_CLRSTARTDET 0x064
> > +#define S6_I2C_CLRGENCALL 0x068
> > +#define S6_I2C_ENABLE 0x06C
> > +#define S6_I2C_STATUS 0x070
> > +#define S6_I2C_STATUS_ACTIVITY 0
> > +#define S6_I2C_STATUS_TFNF 1
> > +#define S6_I2C_STATUS_TFE 2
> > +#define S6_I2C_STATUS_RFNE 3
> > +#define S6_I2C_STATUS_RFF 4
> > +#define S6_I2C_TXFLR 0x074
> > +#define S6_I2C_RXFLR 0x078
> > +#define S6_I2C_SRESET 0x07C
> > +#define S6_I2C_SRESET_IC_SRST 0
> > +#define S6_I2C_SRESET_IC_MASTER_SRST 1
> > +#define S6_I2C_SRESET_IC_SLAVE_SRST 2
> > +#define S6_I2C_TXABRTSOURCE 0x080
> > +
> > +#endif
> > diff --git a/include/linux/i2c/s6000.h b/include/linux/i2c/s6000.h
>
> and again.
>
> > new file mode 100644
> > index 0000000..0b6b0c6
> > --- /dev/null
> > +++ b/include/linux/i2c/s6000.h
> > @@ -0,0 +1,10 @@
> > +#ifndef __LINUX_I2C_S6000_H
> > +#define __LINUX_I2C_S6000_H
> > +
>
> documentation comments would be nice here too.
>
> > +struct s6_i2c_platform_data {
> > + const char *clock;
> > + int bus_num;
> > +};
> > +
> > +#endif
> > +
> > --
> > 1.6.2.107.ge47ee
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
>
> --
> Ben ([email protected], http://www.fluff.org/)
>
> 'a smiley only costs 4 bytes'
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Ben ([email protected], http://www.fluff.org/)

'a smiley only costs 4 bytes'

2009-04-02 11:18:00

by Oskar Schirmer

[permalink] [raw]
Subject: [patch v2] i2c: xtensa s6000 i2c driver

Support for the s6000 on-chip i2c controller.

Signed-off-by: Oskar Schirmer <[email protected]>
Signed-off-by: Daniel Glöckner <[email protected]>
---
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-s6000.c | 407 ++++++++++++++++++++++++++++++++++++++++
drivers/i2c/busses/i2c-s6000.h | 79 ++++++++
include/linux/i2c/s6000.h | 10 +
5 files changed, 507 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-s6000.c
create mode 100644 drivers/i2c/busses/i2c-s6000.h
create mode 100644 include/linux/i2c/s6000.h

Version 2:
o fix copyright notice
o document interface state structure
o translate io helpers from cpp to c
o use dev_printk()
o dropped parens in '&(expression)'
o use resource_size()
o added common i2c module alias
o newlines between logically separate blocks
o clock-to-ns calculation: less accurate, much less object code

Ben, we left the clk-by-name thing in there. The clk API is an
abstraction of the platform and some implementations don't even
support passing NULL as a name (sh, some arms, avr32, mips, ...).
Passing in a string works everywhere so we are on the safe side.

Any objections?

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7f95905..904def4 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -461,6 +461,16 @@ config I2C_S3C2410
Say Y here to include support for I2C controller in the
Samsung S3C2410 based System-on-Chip devices.

+config I2C_S6000
+ tristate "S6000 I2C support"
+ depends on XTENSA_VARIANT_S6000
+ help
+ This driver supports the on chip I2C device on the
+ S6000 xtensa processor family.
+
+ To compile this driver as a module, choose M here. The module
+ will be called i2c-s6000.
+
config I2C_SH7760
tristate "Renesas SH7760 I2C Controller"
depends on CPU_SUBTYPE_SH7760
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 0c2c4b2..f7989d1 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
+obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
diff --git a/drivers/i2c/busses/i2c-s6000.c b/drivers/i2c/busses/i2c-s6000.c
new file mode 100644
index 0000000..c91359f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-s6000.c
@@ -0,0 +1,407 @@
+/*
+ * drivers/i2c/busses/i2c-s6000.c
+ *
+ * Description: Driver for S6000 Family I2C Interface
+ * Copyright (c) 2008 emlix GmbH
+ * Author: Oskar Schirmer <[email protected]>
+ *
+ * Partially based on i2c-bfin-twi.c driver by <[email protected]>
+ * Copyright (c) 2005-2007 Analog Devices, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/i2c/s6000.h>
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <asm/io.h>
+#include "i2c-s6000.h"
+
+#define DRV_NAME "i2c-s6000"
+
+#define POLL_TIMEOUT (2 * HZ)
+
+struct s6i2c_if {
+ u8 __iomem *reg; /* memory mapped registers */
+ int irq;
+ spinlock_t lock;
+ struct i2c_msg *msgs; /* messages currently handled */
+ int msgs_num; /* nb of msgs to do */
+ int msgs_push; /* nb of msgs read/written */
+ int msgs_done; /* nb of msgs finally handled */
+ unsigned push; /* nb of bytes read/written in msg */
+ unsigned done; /* nb of bytes finally handled */
+ int timeout_count; /* timeout retries left */
+ struct timer_list timeout_timer;
+ struct i2c_adapter adap;
+ struct completion complete;
+ struct clk *clk;
+ struct resource *res;
+};
+
+static inline u16 i2c_rd16(struct s6i2c_if *iface, unsigned n)
+{
+ return readw(iface->reg + (n));
+}
+
+static inline void i2c_wr16(struct s6i2c_if *iface, unsigned n, u16 v)
+{
+ writew(v, iface->reg + (n));
+}
+
+static inline u32 i2c_rd32(struct s6i2c_if *iface, unsigned n)
+{
+ return readl(iface->reg + (n));
+}
+
+static inline void i2c_wr32(struct s6i2c_if *iface, unsigned n, u32 v)
+{
+ writel(v, iface->reg + (n));
+}
+
+static struct s6i2c_if s6i2c_if;
+
+static void s6i2c_handle_interrupt(struct s6i2c_if *iface)
+{
+ if (i2c_rd16(iface, S6_I2C_INTRSTAT) & (1 << S6_I2C_INTR_TXABRT)) {
+ i2c_rd16(iface, S6_I2C_CLRTXABRT);
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ complete(&iface->complete);
+ return;
+ }
+ if (iface->msgs_done >= iface->msgs_num) {
+ dev_err(&iface->adap.dev, "s6i2c: spurious I2C irq: %04x\n",
+ i2c_rd16(iface, S6_I2C_INTRSTAT));
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ return;
+ }
+ while ((iface->msgs_push < iface->msgs_num)
+ && (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_TFNF))) {
+ struct i2c_msg *m = &iface->msgs[iface->msgs_push];
+ if (!(m->flags & I2C_M_RD))
+ i2c_wr16(iface, S6_I2C_DATACMD, m->buf[iface->push]);
+ else
+ i2c_wr16(iface, S6_I2C_DATACMD,
+ 1 << S6_I2C_DATACMD_READ);
+ if (++iface->push >= m->len) {
+ iface->push = 0;
+ iface->msgs_push += 1;
+ }
+ }
+ do {
+ struct i2c_msg *m = &iface->msgs[iface->msgs_done];
+ if (!(m->flags & I2C_M_RD)) {
+ if (iface->msgs_done < iface->msgs_push)
+ iface->msgs_done += 1;
+ else
+ break;
+ } else if (i2c_rd16(iface, S6_I2C_STATUS)
+ & (1 << S6_I2C_STATUS_RFNE)) {
+ m->buf[iface->done] = i2c_rd16(iface, S6_I2C_DATACMD);
+ if (++iface->done >= m->len) {
+ iface->done = 0;
+ iface->msgs_done += 1;
+ }
+ } else{
+ break;
+ }
+ } while (iface->msgs_done < iface->msgs_num);
+ if (iface->msgs_done >= iface->msgs_num) {
+ i2c_wr16(iface, S6_I2C_INTRMASK, 1 << S6_I2C_INTR_TXABRT);
+ complete(&iface->complete);
+ } else if (iface->msgs_push >= iface->msgs_num) {
+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
+ (1 << S6_I2C_INTR_RXFULL));
+ } else {
+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
+ (1 << S6_I2C_INTR_TXEMPTY) |
+ (1 << S6_I2C_INTR_RXFULL));
+ }
+}
+
+static irqreturn_t s6i2c_interrupt_entry(int irq, void *dev_id)
+{
+ struct s6i2c_if *iface = dev_id;
+ if (!(i2c_rd16(iface, S6_I2C_STATUS) & ((1 << S6_I2C_INTR_RXUNDER)
+ | (1 << S6_I2C_INTR_RXOVER)
+ | (1 << S6_I2C_INTR_RXFULL)
+ | (1 << S6_I2C_INTR_TXOVER)
+ | (1 << S6_I2C_INTR_TXEMPTY)
+ | (1 << S6_I2C_INTR_RDREQ)
+ | (1 << S6_I2C_INTR_TXABRT)
+ | (1 << S6_I2C_INTR_RXDONE)
+ | (1 << S6_I2C_INTR_ACTIVITY)
+ | (1 << S6_I2C_INTR_STOPDET)
+ | (1 << S6_I2C_INTR_STARTDET)
+ | (1 << S6_I2C_INTR_GENCALL))))
+ return IRQ_NONE;
+
+ spin_lock(&iface->lock);
+ del_timer(&iface->timeout_timer);
+ s6i2c_handle_interrupt(iface);
+ spin_unlock(&iface->lock);
+ return IRQ_HANDLED;
+}
+
+static void s6i2c_timeout(unsigned long data)
+{
+ struct s6i2c_if *iface = (struct s6i2c_if *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&iface->lock, flags);
+ s6i2c_handle_interrupt(iface);
+ if (--iface->timeout_count > 0) {
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ } else {
+ complete(&iface->complete);
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ }
+ spin_unlock_irqrestore(&iface->lock, flags);
+}
+
+static int s6i2c_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct s6i2c_if *iface = adap->algo_data;
+ int i;
+ if (num == 0)
+ return 0;
+ if (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
+ yield();
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ i2c_rd16(iface, S6_I2C_CLRINTR);
+ for (i = 0; i < num; i++) {
+ if (msgs[i].flags & I2C_M_TEN) {
+ dev_err(&adap->dev,
+ "s6i2c: 10 bits addr not supported\n");
+ return -EINVAL;
+ }
+ if (msgs[i].len == 0) {
+ dev_err(&adap->dev,
+ "s6i2c: zero length message not supported\n");
+ return -EINVAL;
+ }
+ if (msgs[i].addr != msgs[0].addr) {
+ dev_err(&adap->dev,
+ "s6i2c: multiple xfer cannot change target\n");
+ return -EINVAL;
+ }
+ }
+
+ iface->msgs = msgs;
+ iface->msgs_num = num;
+ iface->msgs_push = 0;
+ iface->msgs_done = 0;
+ iface->push = 0;
+ iface->done = 0;
+ iface->timeout_count = 10;
+ i2c_wr16(iface, S6_I2C_TAR, msgs[0].addr);
+ i2c_wr16(iface, S6_I2C_ENABLE, 1);
+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXEMPTY) |
+ (1 << S6_I2C_INTR_TXABRT));
+
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ wait_for_completion(&iface->complete);
+ del_timer_sync(&iface->timeout_timer);
+ while (i2c_rd32(iface, S6_I2C_TXFLR) > 0)
+ schedule();
+ while (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
+ schedule();
+
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
+ return iface->msgs_done;
+}
+
+static u32 s6i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm s6i2c_algorithm = {
+ .master_xfer = s6i2c_master_xfer,
+ .functionality = s6i2c_functionality,
+};
+
+static u16 __devinit nanoseconds_on_clk(struct s6i2c_if *iface, u32 ns)
+{
+ u32 dividend = ((clk_get_rate(iface->clk) / 1000) * ns) / 1000000;
+ if (dividend > 0xffff)
+ return 0xffff;
+ return dividend;
+}
+
+static int __devinit s6i2c_probe(struct platform_device *dev)
+{
+ struct s6i2c_if *iface = &s6i2c_if;
+ struct i2c_adapter *p_adap;
+ const char *clock;
+ int bus_num, rc;
+ spin_lock_init(&iface->lock);
+ init_completion(&iface->complete);
+ iface->irq = platform_get_irq(dev, 0);
+ if (iface->irq < 0) {
+ rc = iface->irq;
+ goto err_out;
+ }
+ iface->res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!iface->res) {
+ rc = -ENXIO;
+ goto err_out;
+ }
+ iface->res = request_mem_region(iface->res->start,
+ resource_size(iface->res),
+ dev->dev.bus_id);
+ if (!iface->res) {
+ rc = -EBUSY;
+ goto err_out;
+ }
+ iface->reg = ioremap_nocache(iface->res->start,
+ resource_size(iface->res));
+ if (!iface->reg) {
+ rc = -ENOMEM;
+ goto err_reg;
+ }
+
+ clock = 0;
+ bus_num = -1;
+ if (dev->dev.platform_data) {
+ struct s6_i2c_platform_data *pdata = dev->dev.platform_data;
+ bus_num = pdata->bus_num;
+ clock = pdata->clock;
+ }
+ iface->clk = clk_get(&dev->dev, clock);
+ if (IS_ERR(iface->clk)) {
+ rc = PTR_ERR(iface->clk);
+ goto err_map;
+ }
+ rc = clk_enable(iface->clk);
+ if (rc < 0)
+ goto err_clk_put;
+ init_timer(&iface->timeout_timer);
+ iface->timeout_timer.function = s6i2c_timeout;
+ iface->timeout_timer.data = (unsigned long)iface;
+
+ p_adap = &iface->adap;
+ strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
+ p_adap->algo = &s6i2c_algorithm;
+ p_adap->algo_data = iface;
+ p_adap->nr = bus_num;
+ p_adap->class = 0;
+ p_adap->dev.parent = &dev->dev;
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ rc = request_irq(iface->irq, s6i2c_interrupt_entry,
+ IRQF_SHARED, dev->name, iface);
+ if (rc) {
+ dev_err(&p_adap->dev, "s6i2c: cant get IRQ %d\n", iface->irq);
+ goto err_clk_dis;
+ }
+
+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
+ udelay(1);
+ i2c_wr32(iface, S6_I2C_SRESET, 1 << S6_I2C_SRESET_IC_SRST);
+ i2c_wr16(iface, S6_I2C_CLRTXABRT, 1);
+ i2c_wr16(iface, S6_I2C_CON,
+ (1 << S6_I2C_CON_MASTER) |
+ (S6_I2C_CON_SPEED_NORMAL << S6_I2C_CON_SPEED) |
+ (0 << S6_I2C_CON_10BITSLAVE) |
+ (0 << S6_I2C_CON_10BITMASTER) |
+ (1 << S6_I2C_CON_RESTARTENA) |
+ (1 << S6_I2C_CON_SLAVEDISABLE));
+ i2c_wr16(iface, S6_I2C_SSHCNT, nanoseconds_on_clk(iface, 4000));
+ i2c_wr16(iface, S6_I2C_SSLCNT, nanoseconds_on_clk(iface, 4700));
+ i2c_wr16(iface, S6_I2C_FSHCNT, nanoseconds_on_clk(iface, 600));
+ i2c_wr16(iface, S6_I2C_FSLCNT, nanoseconds_on_clk(iface, 1300));
+ i2c_wr16(iface, S6_I2C_RXTL, 0);
+ i2c_wr16(iface, S6_I2C_TXTL, 0);
+
+ platform_set_drvdata(dev, iface);
+ if (bus_num < 0)
+ rc = i2c_add_adapter(p_adap);
+ else
+ rc = i2c_add_numbered_adapter(p_adap);
+ if (rc)
+ goto err_irq_free;
+ return 0;
+
+err_irq_free:
+ free_irq(iface->irq, iface);
+err_clk_dis:
+ clk_disable(iface->clk);
+err_clk_put:
+ clk_put(iface->clk);
+err_map:
+ iounmap(iface->reg);
+err_reg:
+ release_mem_region(iface->res->start,
+ resource_size(iface->res));
+err_out:
+ return rc;
+}
+
+static int __devexit s6i2c_remove(struct platform_device *pdev)
+{
+ struct s6i2c_if *iface = platform_get_drvdata(pdev);
+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
+ platform_set_drvdata(pdev, NULL);
+ i2c_del_adapter(&iface->adap);
+ free_irq(iface->irq, iface);
+ clk_disable(iface->clk);
+ clk_put(iface->clk);
+ iounmap(iface->reg);
+ release_mem_region(iface->res->start,
+ resource_size(iface->res));
+ return 0;
+}
+
+static struct platform_driver s6i2c_driver = {
+ .probe = s6i2c_probe,
+ .remove = __devexit_p(s6i2c_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init s6i2c_init(void)
+{
+ pr_info("I2C: S6000 I2C driver\n");
+ return platform_driver_register(&s6i2c_driver);
+}
+
+static void __exit s6i2c_exit(void)
+{
+ platform_driver_unregister(&s6i2c_driver);
+}
+
+MODULE_DESCRIPTION("I2C-Bus adapter routines for S6000 I2C");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
+
+subsys_initcall(s6i2c_init);
+module_exit(s6i2c_exit);
diff --git a/drivers/i2c/busses/i2c-s6000.h b/drivers/i2c/busses/i2c-s6000.h
new file mode 100644
index 0000000..ff23b81
--- /dev/null
+++ b/drivers/i2c/busses/i2c-s6000.h
@@ -0,0 +1,79 @@
+/*
+ * drivers/i2c/busses/i2c-s6000.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Emlix GmbH <[email protected]>
+ * Author: Oskar Schirmer <[email protected]>
+ */
+
+#ifndef __DRIVERS_I2C_BUSSES_I2C_S6000_H
+#define __DRIVERS_I2C_BUSSES_I2C_S6000_H
+
+#define S6_I2C_CON 0x000
+#define S6_I2C_CON_MASTER 0
+#define S6_I2C_CON_SPEED 1
+#define S6_I2C_CON_SPEED_NORMAL 1
+#define S6_I2C_CON_SPEED_FAST 2
+#define S6_I2C_CON_SPEED_MASK 3
+#define S6_I2C_CON_10BITSLAVE 3
+#define S6_I2C_CON_10BITMASTER 4
+#define S6_I2C_CON_RESTARTENA 5
+#define S6_I2C_CON_SLAVEDISABLE 6
+#define S6_I2C_TAR 0x004
+#define S6_I2C_TAR_GCORSTART 10
+#define S6_I2C_TAR_SPECIAL 11
+#define S6_I2C_SAR 0x008
+#define S6_I2C_HSMADDR 0x00C
+#define S6_I2C_DATACMD 0x010
+#define S6_I2C_DATACMD_READ 8
+#define S6_I2C_SSHCNT 0x014
+#define S6_I2C_SSLCNT 0x018
+#define S6_I2C_FSHCNT 0x01C
+#define S6_I2C_FSLCNT 0x020
+#define S6_I2C_INTRSTAT 0x02C
+#define S6_I2C_INTRMASK 0x030
+#define S6_I2C_RAWINTR 0x034
+#define S6_I2C_INTR_RXUNDER 0
+#define S6_I2C_INTR_RXOVER 1
+#define S6_I2C_INTR_RXFULL 2
+#define S6_I2C_INTR_TXOVER 3
+#define S6_I2C_INTR_TXEMPTY 4
+#define S6_I2C_INTR_RDREQ 5
+#define S6_I2C_INTR_TXABRT 6
+#define S6_I2C_INTR_RXDONE 7
+#define S6_I2C_INTR_ACTIVITY 8
+#define S6_I2C_INTR_STOPDET 9
+#define S6_I2C_INTR_STARTDET 10
+#define S6_I2C_INTR_GENCALL 11
+#define S6_I2C_RXTL 0x038
+#define S6_I2C_TXTL 0x03C
+#define S6_I2C_CLRINTR 0x040
+#define S6_I2C_CLRRXUNDER 0x044
+#define S6_I2C_CLRRXOVER 0x048
+#define S6_I2C_CLRTXOVER 0x04C
+#define S6_I2C_CLRRDREQ 0x050
+#define S6_I2C_CLRTXABRT 0x054
+#define S6_I2C_CLRRXDONE 0x058
+#define S6_I2C_CLRACTIVITY 0x05C
+#define S6_I2C_CLRSTOPDET 0x060
+#define S6_I2C_CLRSTARTDET 0x064
+#define S6_I2C_CLRGENCALL 0x068
+#define S6_I2C_ENABLE 0x06C
+#define S6_I2C_STATUS 0x070
+#define S6_I2C_STATUS_ACTIVITY 0
+#define S6_I2C_STATUS_TFNF 1
+#define S6_I2C_STATUS_TFE 2
+#define S6_I2C_STATUS_RFNE 3
+#define S6_I2C_STATUS_RFF 4
+#define S6_I2C_TXFLR 0x074
+#define S6_I2C_RXFLR 0x078
+#define S6_I2C_SRESET 0x07C
+#define S6_I2C_SRESET_IC_SRST 0
+#define S6_I2C_SRESET_IC_MASTER_SRST 1
+#define S6_I2C_SRESET_IC_SLAVE_SRST 2
+#define S6_I2C_TXABRTSOURCE 0x080
+
+#endif
diff --git a/include/linux/i2c/s6000.h b/include/linux/i2c/s6000.h
new file mode 100644
index 0000000..d9b34bf
--- /dev/null
+++ b/include/linux/i2c/s6000.h
@@ -0,0 +1,10 @@
+#ifndef __LINUX_I2C_S6000_H
+#define __LINUX_I2C_S6000_H
+
+struct s6_i2c_platform_data {
+ const char *clock; /* the clock to use */
+ int bus_num; /* the bus number to register */
+};
+
+#endif
+
--
1.6.2.107.ge47ee