From: Viet Nga Dao <[email protected]>
Altera EPCQ Controller is a soft IP which enables access to Altera EPCQ and
EPCS flash chips. This patch adds driver for these devices.
Signed-off-by: Viet Nga Dao <[email protected]>
---
.../devicetree/bindings/mtd/altera_epcq.txt | 45 ++
drivers/mtd/devices/Kconfig | 12 +
drivers/mtd/devices/Makefile | 2 +-
drivers/mtd/devices/altera_epcq.c | 804 ++++++++++++++++++++
drivers/mtd/devices/altera_epcq.h | 130 ++++
5 files changed, 992 insertions(+), 1 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mtd/altera_epcq.txt
create mode 100644 drivers/mtd/devices/altera_epcq.c
create mode 100644 drivers/mtd/devices/altera_epcq.h
diff --git a/Documentation/devicetree/bindings/mtd/altera_epcq.txt b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
new file mode 100644
index 0000000..d14f50e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
@@ -0,0 +1,45 @@
+* MTD Altera EPCQ driver
+
+Required properties:
+- compatible: Should be "altr,epcq-1.0"
+- reg: Address and length of the register set for the device. It contains
+ the information of registers in the same order as described by reg-names
+- reg-names: Should contain the reg names
+ "csr_base": Should contain the register configuration base address
+ "data_base": Should contain the data base address
+- is-epcs: boolean type.
+ If present, the device contains EPCS flashes.
+ Otherwise, it contains EPCQ flashes.
+- #address-cells: Must be <1>.
+- #size-cells: Must be <0>.
+- flash device tree subnode, there must be a node with the following fields:
+ - reg: Should contain the flash id
+ - #address-cells: please refer to /mtd/partition.txt
+ - #size-cells: please refer to /mtd/partition.txt
+ For partitions inside each flash, please refer to /mtd/partition.txt
+
+Example:
+
+ epcq_controller_0: epcq@0x000000000 {
+ compatible = "altr,epcq-1.0";
+ reg = <0x00000001 0x00000000 0x00000020>,
+ <0x00000000 0x00000000 0x02000000>;
+ reg-names = "csr_base", "data_base";
+ #address-cells = <1>;
+ #size-cells = <0>;
+ flash0: epcq256@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ partition@0 {
+ /* 16 MB for raw data. */
+ label = "EPCQ Flash 0 raw data";
+ reg = <0x0 0x1000000>;
+ };
+ partition@1000000 {
+ /* 16 MB for jffs2 data. */
+ label = "EPCQ Flash 0 JFFS 2";
+ reg = <0x1000000 0x1000000>;
+ };
+ };
+ }; //end epcq@0x000000000 (epcq_controller_0)
diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index c49d0b1..020b864 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -218,6 +218,18 @@ config MTD_ST_SPI_FSM
SPI Fast Sequence Mode (FSM) Serial Flash Controller and support
for a subset of connected Serial Flash devices.
+config MTD_ALTERA_EPCQ
+ tristate "Support Altera EPCQ/EPCS Flash chips"
+ depends on OF
+ help
+ This enables access to Altera EPCQ/EPCS flash chips, used for data
+ storage. See the driver source for the current list,
+ or to add other chips.
+
+ If you want to compile this driver as a module ( = code which can be
+ inserted in and removed from the running kernel whenever you want),
+ say M here and read <file:Documentation/kbuild/modules.txt>.
+
if MTD_DOCG3
config BCH_CONST_M
default 14
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index f0b0e61..b429c4d 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -16,6 +16,6 @@ obj-$(CONFIG_MTD_SPEAR_SMI) += spear_smi.o
obj-$(CONFIG_MTD_SST25L) += sst25l.o
obj-$(CONFIG_MTD_BCM47XXSFLASH) += bcm47xxsflash.o
obj-$(CONFIG_MTD_ST_SPI_FSM) += st_spi_fsm.o
-
+obj-$(CONFIG_MTD_ALTERA_EPCQ) += altera_epcq.o
CFLAGS_docg3.o += -I$(src)
diff --git a/drivers/mtd/devices/altera_epcq.c b/drivers/mtd/devices/altera_epcq.c
new file mode 100644
index 0000000..09213d5
--- /dev/null
+++ b/drivers/mtd/devices/altera_epcq.c
@@ -0,0 +1,804 @@
+/*
+ * Copyright (C) 2014 Altera Corporation. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/param.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/wait.h>
+
+#include "altera_epcq.h"
+
+/* data structure to maintain flash ids from different vendors */
+struct flash_device {
+ char *name;
+ bool is_epcs;
+ u32 device_id;
+ uint32_t sectorsize_inbytes;
+ uint64_t size_inbytes;
+ u32 pagesize;
+};
+
+#define FLASH_ID(_n, _is_epcs, _id, _ssize, _size, _psize) \
+{ \
+ .name = (_n), \
+ .is_epcs = (_is_epcs), \
+ .device_id = (_id), \
+ .sectorsize_inbytes = (_ssize), \
+ .size_inbytes = (_size), \
+ .pagesize = (_psize), \
+}
+
+static struct flash_device flash_devices[] = {
+ FLASH_ID("epcq16" , 0, 0x15, 0x10000, 0x200000, 0x100),
+ FLASH_ID("epcq32" , 0, 0x16, 0x10000, 0x400000, 0x100),
+ FLASH_ID("epcq64" , 0, 0x17, 0x10000, 0x800000, 0x100),
+ FLASH_ID("epcq128" , 0, 0x18, 0x10000, 0x1000000, 0x100),
+ FLASH_ID("epcq256" , 0, 0x19, 0x10000, 0x2000000, 0x100),
+ FLASH_ID("epcq512" , 0, 0x20, 0x10000, 0x4000000, 0x100),
+
+ FLASH_ID("epcs16" , 1, 0x14, 0x10000, 0x200000, 0x100),
+ FLASH_ID("epcs64" , 1, 0x16, 0x10000, 0x800000, 0x100),
+ FLASH_ID("epcs128" , 1, 0x18, 0x40000, 0x1000000, 0x100),
+};
+
+static inline struct altera_epcq_flash *get_flash_data(struct mtd_info *mtd)
+{
+ return container_of(mtd, struct altera_epcq_flash, mtd);
+}
+
+static u32 altera_epcq_read_sr(struct altera_epcq *dev)
+{
+ return readl(dev->csr_base + EPCQ_SR_REG);
+}
+
+static int altera_epcq_wait_till_ready(struct altera_epcq *dev)
+{
+ unsigned long finish;
+ int status;
+
+ finish = jiffies + EPCQ_MAX_TIME_OUT;
+ do {
+ status = altera_epcq_read_sr(dev);
+ if (status < 0)
+ return status;
+ else if (!(status & EPCQ_SR_WIP))
+ return 0;
+
+ cond_resched();
+ } while (!time_after_eq(jiffies, finish));
+
+ dev_err(&dev->pdev->dev, "epcq controller is busy, timeout\n");
+ return -EBUSY;
+}
+
+static int get_flash_index(u32 flash_id, bool is_epcs)
+{
+ int index;
+
+ for (index = 0; index < ARRAY_SIZE(flash_devices); index++) {
+ if (flash_devices[index].device_id == flash_id &&
+ flash_devices[index].is_epcs == is_epcs)
+ return index;
+ }
+
+ /* Memory chip is not listed and not supported */
+ return -ENODEV;
+}
+
+static int altera_epcq_write_erase_check(struct altera_epcq *dev,
+ bool write_erase)
+{
+ u32 val;
+ u32 mask;
+
+ if (write_erase)
+ mask = EPCQ_ISR_ILLEGAL_WRITE_MASK;
+ else
+ mask = EPCQ_ISR_ILLEGAL_ERASE_MASK;
+
+ val = readl(dev->csr_base + EPCQ_ISR_REG);
+ if (val & mask) {
+ dev_err(&dev->pdev->dev,
+ "write/erase failed, sector might be protected\n");
+ /*clear this status for next use*/
+ writel(val, dev->csr_base + EPCQ_ISR_REG);
+ return -EIO;
+ }
+ return 0;
+}
+
+static int altera_epcq_erase_chip(struct mtd_info *mtd)
+{
+ int ret;
+ u32 val;
+ struct altera_epcq *dev = mtd->priv;
+
+ /* Wait until finished previous write command. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ return ret;
+
+ /* erase chip. */
+ val = EPCQ_MEM_OP_BULK_ERASE_CMD;
+ writel(val, dev->csr_base + EPCQ_MEM_OP_REG);
+
+ /* Wait until finished previous write command. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ return ret;
+
+ /* check whether write triggered a illegal write interrupt */
+ ret = altera_epcq_write_erase_check(dev, 0);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int altera_epcq_addr_to_sector(struct altera_epcq_flash *flash,
+ int addr_offset)
+{
+ int sector = 0;
+ int i;
+
+ for (i = 0; i < flash->num_sectors; i++) {
+ if (addr_offset >= i * flash->mtd.erasesize && addr_offset <
+ (i * flash->mtd.erasesize + flash->mtd.erasesize)) {
+ sector = i;
+ return sector;
+ }
+ }
+ return -1;
+}
+
+static int altera_epcq_erase_sector(struct mtd_info *mtd,
+ int addr_offset)
+{
+ struct altera_epcq_flash *flash = get_flash_data(mtd);
+ struct altera_epcq *dev = mtd->priv;
+ u32 val;
+ int ret;
+ int sector_value;
+
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ return ret;
+
+ sector_value = altera_epcq_addr_to_sector(flash, addr_offset);
+
+ /* sanity check that block_offset is a valid sector number */
+ if (sector_value < 0)
+ return -EINVAL;
+
+ /* sector value should occupy bits 17:8 */
+ val = (sector_value << 8) & EPCQ_MEM_OP_SECTOR_VALUE_MASK;
+
+ /* sector erase commands occupies lower 2 bits */
+ val |= EPCQ_MEM_OP_SECTOR_ERASE_CMD;
+
+ /* write sector erase command to EPCQ_MEM_OP register*/
+ writel(val, dev->csr_base + EPCQ_MEM_OP_REG);
+
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ return ret;
+
+ /* check whether write triggered a illegal write interrupt */
+ ret = altera_epcq_write_erase_check(dev, 0);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int altera_epcq_erase(struct mtd_info *mtd, struct erase_info *e_info)
+{
+ u32 addr;
+ int ret;
+ u32 len;
+ struct altera_epcq_flash *flash = get_flash_data(mtd);
+ struct altera_epcq *dev = mtd->priv;
+
+ addr = e_info->addr;
+ len = e_info->len;
+
+ if (flash->bank > dev->num_flashes - 1) {
+ dev_err(&dev->pdev->dev, "Invalid chip id\n");
+ return -EINVAL;
+ }
+ mutex_lock(&flash->lock);
+
+ /*erase whole chip*/
+ if (len == mtd->size) {
+ if (altera_epcq_erase_chip(mtd)) {
+ e_info->state = MTD_ERASE_FAILED;
+ mutex_unlock(&flash->lock);
+ return -EIO;
+ }
+ /*"sector"-at-a-time erase*/
+ } else {
+ while (len) {
+ ret = altera_epcq_erase_sector(mtd, addr);
+ if (ret) {
+ e_info->state = MTD_ERASE_FAILED;
+ mutex_unlock(&flash->lock);
+ return -EIO;
+ }
+ addr += mtd->erasesize;
+ if (len < mtd->erasesize)
+ len = 0;
+ else
+ len -= mtd->erasesize;
+ }
+ }
+ mutex_unlock(&flash->lock);
+ e_info->state = MTD_ERASE_DONE;
+ mtd_erase_callback(e_info);
+
+ return 0;
+}
+
+static int altera_epcq_read(struct mtd_info *mtd, loff_t from, size_t len,
+ size_t *retlen, u8 *buf)
+{
+ struct altera_epcq_flash *flash = get_flash_data(mtd);
+ struct altera_epcq *dev = mtd->priv;
+ void *src;
+ int ret = 0;
+
+ if (!flash || !dev)
+ return -ENODEV;
+
+ if (flash->bank > dev->num_flashes - 1) {
+ dev_err(&dev->pdev->dev, "Invalid chip id\n");
+ return -EINVAL;
+ }
+
+ src = dev->data_base + from;
+
+ mutex_lock(&flash->lock);
+ /* wait till previous write/erase is done. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ goto err;
+
+ memcpy_fromio(buf, (u8 *)src, len);
+ *retlen = len;
+
+err:
+ mutex_unlock(&flash->lock);
+ return ret;
+}
+
+static int altera_epcq_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u8 *buf)
+{
+ struct altera_epcq_flash *flash = get_flash_data(mtd);
+ struct altera_epcq *dev = mtd->priv;
+ void *dest;
+ int ret = 0;
+
+ if (!flash || !dev)
+ return -ENODEV;
+
+ if (flash->bank > dev->num_flashes - 1) {
+ dev_err(&dev->pdev->dev, "Invalid chip id\n");
+ return -EINVAL;
+ }
+ dest = dev->data_base + to;
+
+ mutex_lock(&flash->lock);
+
+ /* wait until finished previous write command. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ goto err;
+
+ memcpy_toio(dest, buf, len);
+ *retlen += len;
+
+ /* wait until finished previous write command. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ goto err;
+
+ /* check whether write triggered a illegal write interrupt */
+ ret = altera_epcq_write_erase_check(dev, 1);
+ if (ret < 0)
+ goto err;
+
+err:
+ mutex_unlock(&flash->lock);
+ return ret;
+}
+
+static int altera_epcq_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ struct altera_epcq_flash *flash = get_flash_data(mtd);
+ struct altera_epcq *dev = mtd->priv;
+ uint32_t offset = ofs;
+ int ret = 0;
+ u32 sector_start, sector_end;
+ u32 num_sectors;
+ u32 mem_op;
+ unsigned sr_bp = 0;
+ unsigned sr_tb = 0;
+
+ sector_start = altera_epcq_addr_to_sector(flash, offset);
+ sector_end = altera_epcq_addr_to_sector(flash, offset + len);
+ num_sectors = flash->num_sectors;
+ dev_dbg(&dev->pdev->dev,
+ "%s: num_setor is %u,sector start is %u,sector end is %u\n",
+ __func__, num_sectors, sector_start, sector_end);
+
+ mutex_lock(&flash->lock);
+ /* wait until finished previous write command. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ goto err;
+
+ if (sector_start >= num_sectors/2) {
+ if (sector_start < num_sectors-(num_sectors / 4))
+ sr_bp = __ilog2_u32(num_sectors);
+ else if (sector_start < num_sectors-(num_sectors / 8))
+ sr_bp = __ilog2_u32(num_sectors) - 1;
+ else if (sector_start < num_sectors-(num_sectors / 16))
+ sr_bp = __ilog2_u32(num_sectors) - 2;
+ else if (sector_start < num_sectors-(num_sectors / 32))
+ sr_bp = __ilog2_u32(num_sectors) - 3;
+ else if (sector_start < num_sectors-(num_sectors / 64))
+ sr_bp = __ilog2_u32(num_sectors) - 4;
+ else if (sector_start < num_sectors-(num_sectors / 128))
+ sr_bp = __ilog2_u32(num_sectors) - 5;
+ else if (sector_start < num_sectors-(num_sectors / 256))
+ sr_bp = __ilog2_u32(num_sectors) - 6;
+ else if (sector_start < num_sectors-(num_sectors / 512))
+ sr_bp = __ilog2_u32(num_sectors) - 7;
+ else if (sector_start < num_sectors-(num_sectors / 1024))
+ sr_bp = __ilog2_u32(num_sectors) - 8;
+ else
+ sr_bp = 0; /* non area protected */
+
+ if (sr_bp < 0) {
+ dev_err(&dev->pdev->dev, "%s: address is out of range\n"
+ , __func__);
+ ret = -EINVAL;
+ goto err;
+ }
+ /*set TB = 0*/
+ sr_tb = 0;
+
+ } else {
+ if (sector_end < 1)
+ sr_bp = 1;
+ else if (sector_end < 2)
+ sr_bp = 2;
+ else if (sector_end < 4)
+ sr_bp = 3;
+ else if (sector_end < 8)
+ sr_bp = 4;
+ else if (sector_end < 16)
+ sr_bp = 5;
+ else if (sector_end < 32)
+ sr_bp = 6;
+ else if (sector_end < 64)
+ sr_bp = 7;
+ else if (sector_end < 128)
+ sr_bp = 8;
+ else if (sector_end < 256)
+ sr_bp = 9;
+ else if (sector_end < 512)
+ sr_bp = 10;
+ else
+ sr_bp = 16; /*protect all areas*/
+
+ sr_tb = 1;
+ }
+
+ mem_op = (sr_tb << 12) | (sr_bp << 8);
+ mem_op &= EPCQ_MEM_OP_SECTOR_PROTECT_VALUE_MASK;
+ mem_op |= EPCQ_MEM_OP_SECTOR_PROTECT_CMD;
+ writel(mem_op, dev->csr_base + EPCQ_MEM_OP_REG);
+
+err:
+ mutex_unlock(&flash->lock);
+ return ret;
+}
+
+static int altera_epcq_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ struct altera_epcq_flash *flash = get_flash_data(mtd);
+ struct altera_epcq *dev = mtd->priv;
+
+ int ret = 0;
+ u32 mem_op;
+
+ mutex_lock(&flash->lock);
+ /* wait until finished previous write command. */
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ goto err;
+ dev_info(&dev->pdev->dev, "Unlock all protected area\n");
+ mem_op = 0;
+ mem_op &= EPCQ_MEM_OP_SECTOR_PROTECT_VALUE_MASK;
+ mem_op |= EPCQ_MEM_OP_SECTOR_PROTECT_CMD;
+ writel(mem_op, dev->csr_base + EPCQ_MEM_OP_REG);
+
+err:
+ mutex_unlock(&flash->lock);
+ return ret;
+}
+
+static void altera_epcq_chip_select(struct altera_epcq *dev, u32 bank)
+{
+ u32 val = 0;
+
+ switch (bank) {
+ case 0:
+ val = EPCQ_CHIP_SELECT_0;
+ break;
+ case 1:
+ val = EPCQ_CHIP_SELECT_1;
+ break;
+ case 2:
+ val = EPCQ_CHIP_SELECT_2;
+ break;
+ default:
+ return;
+ }
+
+ writel(val, dev->csr_base + EPCQ_CHIP_SELECT_REG);
+}
+
+static int altera_epcq_probe_flash(struct altera_epcq *dev, u32 bank)
+{
+ int ret = 0;
+ u32 val = 0;
+
+ mutex_lock(&dev->lock);
+
+ /*select bank*/
+ altera_epcq_chip_select(dev, bank);
+
+ ret = altera_epcq_wait_till_ready(dev);
+ if (ret)
+ goto err;
+
+ /* get device sillicon id */
+ if (dev->is_epcs)
+ val = readl(dev->csr_base + EPCQ_SID_REG);
+ else
+ val = readl(dev->csr_base + EPCQ_RDID_REG);
+
+ /* get flash index based on the device list*/
+ ret = get_flash_index(val, dev->is_epcs);
+ return 0;
+err:
+ mutex_unlock(&dev->lock);
+ return ret;
+}
+
+static int altera_epcq_probe_config_dt(struct platform_device *pdev,
+ struct device_node *np,
+ struct altera_epcq_plat_data *pdata)
+{
+ struct device_node *pp = NULL;
+ struct resource *epcq_res;
+ int i = 0;
+ u32 id;
+
+ pdata->is_epcs = of_property_read_bool(np, "is-epcs");
+
+ epcq_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ "csr_base");
+ if (!epcq_res) {
+ dev_err(&pdev->dev, "resource csr base is not defined\n");
+ return -ENODEV;
+ }
+
+ pdata->csr_base = devm_ioremap_resource(&pdev->dev, epcq_res);
+ if (IS_ERR(pdata->csr_base)) {
+ dev_err(&pdev->dev, "%s: ERROR: failed to map csr base\n",
+ __func__);
+ return PTR_ERR(pdata->csr_base);
+ }
+
+ epcq_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+ "data_base");
+ if (!epcq_res) {
+ dev_err(&pdev->dev, "resource data base is not defined\n");
+ return -ENODEV;
+ }
+
+ pdata->data_base = devm_ioremap_resource(&pdev->dev, epcq_res);
+ if (IS_ERR(pdata->data_base)) {
+ dev_err(&pdev->dev, "%s: ERROR: failed to map data base\n",
+ __func__);
+ return PTR_ERR(pdata->data_base);
+ }
+
+ pdata->board_flash_info = devm_kzalloc(&pdev->dev,
+ sizeof(*pdata->board_flash_info),
+ GFP_KERNEL);
+
+ /* Fill structs for each subnode (flash device) */
+ while ((pp = of_get_next_child(np, pp))) {
+ struct altera_epcq_flash_info *flash_info;
+
+ flash_info = &pdata->board_flash_info[i];
+ pdata->np[i] = pp;
+
+ /* Read bank id from DT */
+ if (of_get_property(pp, "reg", &id))
+ pdata->board_flash_info[i].bank = id;
+ i++;
+ }
+ pdata->num_flashes = i;
+ return 0;
+}
+
+static int altera_epcq_setup_banks(struct platform_device *pdev,
+ u32 bank, struct device_node *np,
+ struct altera_epcq_plat_data *pdata)
+{
+ struct altera_epcq *dev = platform_get_drvdata(pdev);
+ struct mtd_part_parser_data ppdata = {};
+ struct altera_epcq_flash_info *flash_info;
+ struct altera_epcq_flash *flash;
+ struct mtd_partition *parts = NULL;
+ int count = 0;
+ int flash_index;
+ int ret = 0;
+ uint64_t size;
+ uint32_t sector_size;
+
+ flash_info = &pdata->board_flash_info[bank];
+ if (!flash_info)
+ return -ENODEV;
+
+ if (bank > pdata->num_flashes - 1)
+ return -EINVAL;
+
+ flash = devm_kzalloc(&pdev->dev, sizeof(*flash), GFP_KERNEL);
+ if (!flash)
+ return -ENOMEM;
+ flash->bank = bank;
+
+ mutex_init(&flash->lock);
+
+ /* verify whether flash is really present on board */
+ flash_index = altera_epcq_probe_flash(dev, bank);
+ if (flash_index < 0) {
+ dev_info(&dev->pdev->dev, "epcq:flash%d not found\n",
+ flash->bank);
+ return flash_index;
+ }
+
+ dev->flash[bank] = flash;
+
+ size = flash_devices[flash_index].size_inbytes;
+ sector_size = flash_devices[flash_index].sectorsize_inbytes;
+ /*use do_div instead of plain div to avoid linker err*/
+ do_div(size, sector_size);
+ flash->num_sectors = size;
+
+ /*mtd framework */
+ flash->mtd.priv = dev;
+ flash->mtd.name = flash_devices[flash_index].name;
+ flash->mtd.type = MTD_NORFLASH;
+ flash->mtd.writesize = 1;
+ flash->mtd.flags = MTD_CAP_NORFLASH;
+ flash->mtd.size = flash_devices[flash_index].size_inbytes;
+ flash->mtd.erasesize = flash_devices[flash_index].sectorsize_inbytes;
+ flash->mtd._erase = altera_epcq_erase;
+ flash->mtd._read = altera_epcq_read;
+ flash->mtd._write = altera_epcq_write;
+ flash->mtd._lock = altera_epcq_lock;
+ flash->mtd._unlock = altera_epcq_unlock;
+
+ dev_info(&pdev->dev, "mtd .name=%s .size=0x%llx (%lluM)\n",
+ flash->mtd.name, (long long)flash->mtd.size,
+ (long long)(flash->mtd.size >> 20));
+
+ dev_info(&pdev->dev, ".erasesize = 0x%x(%uK)\n",
+ flash->mtd.erasesize, flash->mtd.erasesize >> 10);
+
+ ppdata.of_node = np;
+
+ ret = mtd_device_parse_register(&flash->mtd, NULL, &ppdata, parts,
+ count);
+ if (ret) {
+ dev_err(&pdev->dev, "Err MTD partition=%d\n", ret);
+ goto err;
+ }
+
+ return 0;
+
+err:
+ mtd_device_unregister(&flash->mtd);
+ return ret;
+}
+
+static int altera_epcq_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct altera_epcq_plat_data *pdata = NULL;
+ struct altera_epcq *dev;
+ int ret = 0;
+ int i;
+
+ if (!np) {
+ ret = -ENODEV;
+ dev_err(&pdev->dev, "no device found\n");
+ goto err;
+ }
+
+ pdata = devm_kzalloc(&pdev->dev,
+ sizeof(struct altera_epcq_plat_data),
+ GFP_KERNEL);
+
+ if (!pdata) {
+ ret = -ENOMEM;
+ dev_err(&pdev->dev, "%s: ERROR: no memory\n", __func__);
+ goto err;
+ }
+ ret = altera_epcq_probe_config_dt(pdev, np, pdata);
+ if (ret) {
+ ret = -ENODEV;
+ dev_err(&pdev->dev, "probe fail\n");
+ goto err;
+ }
+
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_ATOMIC);
+ if (!dev) {
+ ret = -ENOMEM;
+ dev_err(&pdev->dev, "mem alloc fail\n");
+ goto err;
+ }
+ mutex_init(&dev->lock);
+ dev->pdev = pdev;
+ dev->is_epcs = pdata->is_epcs;
+ dev->csr_base = pdata->csr_base;
+ dev->data_base = pdata->data_base;
+
+ /*check number of flashes*/
+ dev->num_flashes = pdata->num_flashes;
+ if (dev->num_flashes > MAX_NUM_FLASH_CHIP) {
+ dev_err(&pdev->dev, "exceeding max number of flashes\n");
+ dev->num_flashes = MAX_NUM_FLASH_CHIP;
+ }
+
+ /* check clock*/
+ dev->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(dev->clk)) {
+ ret = PTR_ERR(dev->clk);
+ goto err;
+ }
+ ret = clk_prepare_enable(dev->clk);
+ if (ret)
+ goto err;
+
+ platform_set_drvdata(pdev, dev);
+
+ /* loop for each serial flash which is connected to epcq */
+ for (i = 0; i < dev->num_flashes; i++) {
+ ret = altera_epcq_setup_banks(pdev, i, pdata->np[i], pdata);
+ if (ret) {
+ dev_err(&pdev->dev, "bank setup failed\n");
+ goto err_bank_setup;
+ }
+ }
+
+ return 0;
+
+err_bank_setup:
+ clk_disable_unprepare(dev->clk);
+err:
+ return ret;
+}
+
+static int altera_epcq_remove(struct platform_device *pdev)
+{
+ struct altera_epcq *dev;
+ struct altera_epcq_flash *flash;
+ int ret, i;
+
+ dev = platform_get_drvdata(pdev);
+
+ /* clean up for all nor flash */
+ for (i = 0; i < dev->num_flashes; i++) {
+ flash = dev->flash[i];
+ if (!flash)
+ continue;
+
+ /* clean up mtd stuff */
+ ret = mtd_device_unregister(&flash->mtd);
+ if (ret)
+ dev_err(&pdev->dev, "error removing mtd\n");
+ }
+
+ clk_disable_unprepare(dev->clk);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int altera_epcq_suspend(struct device *dev)
+{
+ struct altera_epcq *sdev = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(sdev->clk);
+
+ return 0;
+}
+
+static int altera_epcq_resume(struct device *dev)
+{
+ struct altera_epcq *sdev = dev_get_drvdata(dev);
+ int ret = -EPERM;
+
+ ret = clk_prepare_enable(sdev->clk);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(altera_epcq_pm_ops, altera_epcq_suspend,
+ altera_epcq_resume);
+#endif
+
+static const struct of_device_id altera_epcq_id_table[] = {
+ { .compatible = "altr,epcq-1.0" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, altera_epcq_id_table);
+
+static struct platform_driver altera_epcq_driver = {
+ .driver = {
+ .name = ALTERA_EPCQ_RESOURCE_NAME,
+ .bus = &platform_bus_type,
+ .owner = THIS_MODULE,
+ .of_match_table = altera_epcq_id_table,
+#ifdef CONFIG_PM
+ .pm = &altera_epcq_pm_ops,
+#endif
+ },
+ .probe = altera_epcq_probe,
+ .remove = altera_epcq_remove,
+};
+module_platform_driver(altera_epcq_driver);
+
+MODULE_AUTHOR("Viet Nga Dao <[email protected]>");
+MODULE_DESCRIPTION("MTD Altera EPCQ Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mtd/devices/altera_epcq.h b/drivers/mtd/devices/altera_epcq.h
new file mode 100644
index 0000000..c3d15e5
--- /dev/null
+++ b/drivers/mtd/devices/altera_epcq.h
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2014 Altera Corporation. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ALTERA_ECPQ_H
+#define __ALTERA_ECPQ_H
+
+#define ALTERA_EPCQ_RESOURCE_NAME "altera_epcq"
+/* max possible slots for serial flash chip in the EPCQ controller */
+#define MAX_NUM_FLASH_CHIP 3
+
+/* macro to define partitions for flash devices */
+#define DEFINE_PARTS(n, of, s) \
+{ \
+ .name = n, \
+ .offset = of, \
+ .size = s, \
+}
+
+struct altera_epcq_flash_info {
+ u32 bank;
+ struct mtd_partition *partitions;
+ int nr_partitions;
+};
+
+struct altera_epcq_plat_data {
+ void __iomem *csr_base;
+ void __iomem *data_base;
+ bool is_epcs;
+ u32 num_flashes;
+ struct altera_epcq_flash_info *board_flash_info;
+ struct device_node *np[MAX_NUM_FLASH_CHIP];
+};
+
+struct altera_epcq {
+ struct clk *clk;
+ bool is_epcs;
+ struct mutex lock; /*device lock*/
+ void __iomem *csr_base;
+ void __iomem *data_base;
+ struct platform_device *pdev;
+ u32 num_flashes;
+ struct altera_epcq_flash *flash[MAX_NUM_FLASH_CHIP];
+};
+
+struct altera_epcq_flash {
+ u32 bank;
+ u32 num_sectors;
+ u32 num_parts;
+ struct mtd_partition *parts;
+ struct mutex lock; /*flash lock*/
+ struct mtd_info mtd;
+};
+
+/* Define max times to check status register before we give up. */
+#define EPCQ_MAX_TIME_OUT (40 * HZ)
+
+/* defines for status register */
+#define EPCQ_SR_REG 0x0
+#define EPCQ_SR_WIP_MASK 0x00000001
+#define EPCQ_SR_WIP 0x1
+#define EPCQ_SR_WEL 0x2
+#define EPCQ_SR_BP0 0x4
+#define EPCQ_SR_BP1 0x8
+#define EPCQ_SR_BP2 0x10
+#define EPCQ_SR_BP3 0x40
+#define EPCQ_SR_TB 0x20
+
+/* defines for device id register */
+#define EPCQ_SID_REG 0x4
+#define EPCQ_RDID_REG 0x8
+#define EPCQ_RDID_MASK 0x000000FF
+/*
+ * EPCQ_MEM_OP register offset
+ *
+ * The EPCQ_MEM_OP register is used to do memory protect and erase operations
+ *
+ */
+#define EPCQ_MEM_OP_REG 0xC
+
+#define EPCQ_MEM_OP_CMD_MASK 0x00000003
+#define EPCQ_MEM_OP_BULK_ERASE_CMD 0x00000001
+#define EPCQ_MEM_OP_SECTOR_ERASE_CMD 0x00000002
+#define EPCQ_MEM_OP_SECTOR_PROTECT_CMD 0x00000003
+#define EPCQ_MEM_OP_SECTOR_VALUE_MASK 0x0003FF00
+#define EPCQ_MEM_OP_SECTOR_PROTECT_VALUE_MASK 0x00001F00
+#define EPCQ_MEM_OP_SECTOR_PROTECT_SHIFT 8
+/*
+ * EPCQ_ISR register offset
+ *
+ * The EPCQ_ISR register is used to determine whether an invalid write or erase
+ * operation trigerred an interrupt
+ *
+ */
+#define EPCQ_ISR_REG 0x10
+
+#define EPCQ_ISR_ILLEGAL_ERASE_MASK 0x00000001
+#define EPCQ_ISR_ILLEGAL_WRITE_MASK 0x00000002
+
+/*
+ * EPCQ_IMR register offset
+ *
+ * The EPCQ_IMR register is used to mask the invalid erase or the invalid write
+ * interrupts.
+ *
+ */
+#define EPCQ_IMR_REG 0x14
+#define EPCQ_IMR_ILLEGAL_ERASE_MASK 0x00000001
+
+#define EPCQ_IMR_ILLEGAL_WRITE_MASK 0x00000002
+
+#define EPCQ_CHIP_SELECT_REG 0x18
+#define EPCQ_CHIP_SELECT_MASK 0x00000007
+#define EPCQ_CHIP_SELECT_0 0x00000001
+#define EPCQ_CHIP_SELECT_1 0x00000002
+#define EPCQ_CHIP_SELECT_2 0x00000004
+
+#endif /* __ALTERA_ECPQ_H */
--
1.7.7.4
On Tue, Jan 27, 2015 at 02:53:59PM +0800, Viet Nga Dao wrote:
> On Tue, Jan 20, 2015 at 10:05 AM, Viet Nga Dao <[email protected]> wrote:
> > On Thu, Jan 15, 2015 at 5:27 PM, Viet Nga Dao <[email protected]> wrote:
> >> On Tue, Jan 13, 2015 at 11:33 AM, Brian Norris
> >> <[email protected]> wrote:
> >>> On Thu, Dec 18, 2014 at 12:23:16AM -0800, [email protected] wrote:
> >>>> From: Viet Nga Dao <[email protected]>
> >> That is why if rewrite the drivers to follow spi-nor structure, it
> >> will require extra decoding works for the only few used opcodes.
> >>
> >I think you'd only have some very trivial work here.
> >
> >There would be some small work to reintroduce a properly-replaceable ID
> >table, and callbacks like ->lock() and ->unlock(), but those should be
> >implemented in spi-nor.c sooner or later anyway.
> >
>
> I am trying to modify the code to follow your recommendation. However,
> for lock and unlock functions, i have to implement it in spi_nor.c ,
> am i right? If yes, currently we already have existing spi_nor_lock
> and spi_nor_unlock functions but they could not apply for my driver.
> Should i create a new functions named altera_epcq_lock and unlock and
> then map it to callback functions or i should the put those code
> sunder existing spi_nor_lock/unlock?
We probably want a replaceable spi_nor callback that does the
flash-specific unlock. spi_nor_lock/unlock would then call the
nor->unlock() / nor->lock() functions for you, when present.
Some of the existing code should move into their own spi_nor_st_lock() /
spi_nor_st_unlock() functions.
> >>>> diff --git a/Documentation/devicetree/bindings/mtd/altera_epcq.txt b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
> >>>> new file mode 100644
> >>>> index 0000000..d14f50e
> >>>> --- /dev/null
> >>>> +++ b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
> >>>> @@ -0,0 +1,45 @@
> >>>> +* MTD Altera EPCQ driver
> >>>> +
> >>>> +Required properties:
> >>>> +- compatible: Should be "altr,epcq-1.0"
> >>>> +- reg: Address and length of the register set for the device. It contains
> >>>> + the information of registers in the same order as described by reg-names
> >>>> +- reg-names: Should contain the reg names
> >>>> + "csr_base": Should contain the register configuration base address
> >>>> + "data_base": Should contain the data base address
> >>>> +- is-epcs: boolean type.
> >>>> + If present, the device contains EPCS flashes.
> >>>> + Otherwise, it contains EPCQ flashes.
> >>>> +- #address-cells: Must be <1>.
> >>>> +- #size-cells: Must be <0>.
> >>>> +- flash device tree subnode, there must be a node with the following fields:
> >>>
> >>> These subnodes definitely require a 'compatible' string. Perhaps they
> >>> should be used to differentiate EPCS vs. EPCQ. Does "is-epcs" really
> >>> need to be in the top-level controller node?
> >>>
> >>>> + - reg: Should contain the flash id
> >>>
> >>> Should, or must? (This question is relevant, because you seem to make it
> >>> optional in your code.) And what does the "flash ID" mean? It seems like
> >>> you're using as a chip-select or bank index.
> >>>
> Yes, this is used for chip select. It is required, not optional. This
> to ID for each flash in the device
OK, so correct the language here and enforce this in your driver. Right
now, you don't fail gracefully if this is missing.
> >>>> + if (sector_start < num_sectors-(num_sectors / 4))
> >>>> + sr_bp = __ilog2_u32(num_sectors);
> >>>> + else if (sector_start < num_sectors-(num_sectors / 8))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 1;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 16))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 2;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 32))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 3;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 64))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 4;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 128))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 5;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 256))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 6;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 512))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 7;
> >>>> + else if (sector_start < num_sectors-(num_sectors / 1024))
> >>>> + sr_bp = __ilog2_u32(num_sectors) - 8;
> >>>> + else
> >>>> + sr_bp = 0; /* non area protected */
> >>>
> >>> Yikes, that's ugly! And I'm not sure it matches the EPCQ doc I found.
> >>> I'm pretty sure you can rewrite this if/else-if/else block in about 1
> >>> line though.
> >>>
> Yes, i understand that it looks ugly. But it is the best i can do
> since this function has to satisfy for all the supported devices
> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf, start
> from page 19)
Did you even try? It was possible to simplify the other case, and I'm
pretty sure this case can be simplified too. How about this? I hacked
this together and it seems to match:
if (sector_start <= num_sectors / 2)
sr_bp = __ilog2_u32(num_sectors);
else
sr_bp = fls(num_sectors - 1 - sector_start) + 1;
> >>>> +
> >>>> + if (sr_bp < 0) {
> >>>
> >>> sr_bp is unsigned, so this is never true.
> >>>
> Ok. I will change to int type.
Are there ever negative values?
> >>>> +static int altera_epcq_probe_config_dt(struct platform_device *pdev,
> >>>> + struct device_node *np,
> >>>> + struct altera_epcq_plat_data *pdata)
> >>>> +{
> >>>> + struct device_node *pp = NULL;
> >>>> + struct resource *epcq_res;
> >>>> + int i = 0;
> >>>> + u32 id;
...
> >>>> + pdata->np[i] = pp;
> >>>> +
> >>>> + /* Read bank id from DT */
> >>>> + if (of_get_property(pp, "reg", &id))
I just realized; you're not using this correctly. of_get_property()
returns the *length* in the third parameter, so you're not actually
saving the bank ID here. You probably want of_property_read_u32()
instead.
> >>>
> >>> Is this property optional? Your DT binding doc doesn't make it clear,
> >>> but it seems like a property which would be wise to require (i.e., not
> >>> optional).
^^^ so there should be a failure case, where you return failure if the
property is missing.
> >>>> + pdata->board_flash_info[i].bank = id;
> >>>> + i++;
> >>>> + }
> >>>> + pdata->num_flashes = i;
> >>>> + return 0;
> >>>> +}
Brian
On Thu, Feb 5, 2015 at 4:37 AM, Brian Norris
<[email protected]> wrote:
> On Tue, Jan 27, 2015 at 02:53:59PM +0800, Viet Nga Dao wrote:
>> On Tue, Jan 20, 2015 at 10:05 AM, Viet Nga Dao <[email protected]> wrote:
>> > On Thu, Jan 15, 2015 at 5:27 PM, Viet Nga Dao <[email protected]> wrote:
>> >> On Tue, Jan 13, 2015 at 11:33 AM, Brian Norris
>> >> <[email protected]> wrote:
>> >>> On Thu, Dec 18, 2014 at 12:23:16AM -0800, [email protected] wrote:
>> >>>> From: Viet Nga Dao <[email protected]>
>
>> >> That is why if rewrite the drivers to follow spi-nor structure, it
>> >> will require extra decoding works for the only few used opcodes.
>> >>
>> >I think you'd only have some very trivial work here.
>> >
>> >There would be some small work to reintroduce a properly-replaceable ID
>> >table, and callbacks like ->lock() and ->unlock(), but those should be
>> >implemented in spi-nor.c sooner or later anyway.
>> >
>>
>> I am trying to modify the code to follow your recommendation. However,
>> for lock and unlock functions, i have to implement it in spi_nor.c ,
>> am i right? If yes, currently we already have existing spi_nor_lock
>> and spi_nor_unlock functions but they could not apply for my driver.
>> Should i create a new functions named altera_epcq_lock and unlock and
>> then map it to callback functions or i should the put those code
>> sunder existing spi_nor_lock/unlock?
>
> We probably want a replaceable spi_nor callback that does the
> flash-specific unlock. spi_nor_lock/unlock would then call the
> nor->unlock() / nor->lock() functions for you, when present.
> Some of the existing code should move into their own spi_nor_st_lock() /
> spi_nor_st_unlock() functions.
>
When this will be implemented? For this time being, what i should do then?
>> >>>> diff --git a/Documentation/devicetree/bindings/mtd/altera_epcq.txt b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>> >>>> new file mode 100644
>> >>>> index 0000000..d14f50e
>> >>>> --- /dev/null
>> >>>> +++ b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>> >>>> @@ -0,0 +1,45 @@
>> >>>> +* MTD Altera EPCQ driver
>> >>>> +
>> >>>> +Required properties:
>> >>>> +- compatible: Should be "altr,epcq-1.0"
>> >>>> +- reg: Address and length of the register set for the device. It contains
>> >>>> + the information of registers in the same order as described by reg-names
>> >>>> +- reg-names: Should contain the reg names
>> >>>> + "csr_base": Should contain the register configuration base address
>> >>>> + "data_base": Should contain the data base address
>> >>>> +- is-epcs: boolean type.
>> >>>> + If present, the device contains EPCS flashes.
>> >>>> + Otherwise, it contains EPCQ flashes.
>> >>>> +- #address-cells: Must be <1>.
>> >>>> +- #size-cells: Must be <0>.
>> >>>> +- flash device tree subnode, there must be a node with the following fields:
>> >>>
>> >>> These subnodes definitely require a 'compatible' string. Perhaps they
>> >>> should be used to differentiate EPCS vs. EPCQ. Does "is-epcs" really
>> >>> need to be in the top-level controller node?
>> >>>
>> >>>> + - reg: Should contain the flash id
>> >>>
>> >>> Should, or must? (This question is relevant, because you seem to make it
>> >>> optional in your code.) And what does the "flash ID" mean? It seems like
>> >>> you're using as a chip-select or bank index.
>> >>>
>> Yes, this is used for chip select. It is required, not optional. This
>> to ID for each flash in the device
>
> OK, so correct the language here and enforce this in your driver. Right
> now, you don't fail gracefully if this is missing.
>
>> >>>> + if (sector_start < num_sectors-(num_sectors / 4))
>> >>>> + sr_bp = __ilog2_u32(num_sectors);
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 8))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 1;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 16))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 2;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 32))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 3;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 64))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 4;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 128))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 5;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 256))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 6;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 512))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 7;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 1024))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 8;
>> >>>> + else
>> >>>> + sr_bp = 0; /* non area protected */
>> >>>
>> >>> Yikes, that's ugly! And I'm not sure it matches the EPCQ doc I found.
>> >>> I'm pretty sure you can rewrite this if/else-if/else block in about 1
>> >>> line though.
>> >>>
>> Yes, i understand that it looks ugly. But it is the best i can do
>> since this function has to satisfy for all the supported devices
>> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf, start
>> from page 19)
>
> Did you even try? It was possible to simplify the other case, and I'm
> pretty sure this case can be simplified too. How about this? I hacked
> this together and it seems to match:
>
> if (sector_start <= num_sectors / 2)
> sr_bp = __ilog2_u32(num_sectors);
> else
> sr_bp = fls(num_sectors - 1 - sector_start) + 1;
>
>> >>>> +
>> >>>> + if (sr_bp < 0) {
>> >>>
>> >>> sr_bp is unsigned, so this is never true.
>> >>>
>> Ok. I will change to int type.
>
> Are there ever negative values?
>
>> >>>> +static int altera_epcq_probe_config_dt(struct platform_device *pdev,
>> >>>> + struct device_node *np,
>> >>>> + struct altera_epcq_plat_data *pdata)
>> >>>> +{
>> >>>> + struct device_node *pp = NULL;
>> >>>> + struct resource *epcq_res;
>> >>>> + int i = 0;
>> >>>> + u32 id;
> ...
>> >>>> + pdata->np[i] = pp;
>> >>>> +
>> >>>> + /* Read bank id from DT */
>> >>>> + if (of_get_property(pp, "reg", &id))
>
> I just realized; you're not using this correctly. of_get_property()
> returns the *length* in the third parameter, so you're not actually
> saving the bank ID here. You probably want of_property_read_u32()
> instead.
>
>> >>>
>> >>> Is this property optional? Your DT binding doc doesn't make it clear,
>> >>> but it seems like a property which would be wise to require (i.e., not
>> >>> optional).
>
> ^^^ so there should be a failure case, where you return failure if the
> property is missing.
>
>> >>>> + pdata->board_flash_info[i].bank = id;
>> >>>> + i++;
>> >>>> + }
>> >>>> + pdata->num_flashes = i;
>> >>>> + return 0;
>> >>>> +}
>
> Brian
--
Nga
On Thu, Feb 5, 2015 at 4:37 AM, Brian Norris
<[email protected]> wrote:
> On Tue, Jan 27, 2015 at 02:53:59PM +0800, Viet Nga Dao wrote:
>> On Tue, Jan 20, 2015 at 10:05 AM, Viet Nga Dao <[email protected]> wrote:
>> > On Thu, Jan 15, 2015 at 5:27 PM, Viet Nga Dao <[email protected]> wrote:
>> >> On Tue, Jan 13, 2015 at 11:33 AM, Brian Norris
>> >> <[email protected]> wrote:
>> >>> On Thu, Dec 18, 2014 at 12:23:16AM -0800, [email protected] wrote:
>> >>>> From: Viet Nga Dao <[email protected]>
>
>> >> That is why if rewrite the drivers to follow spi-nor structure, it
>> >> will require extra decoding works for the only few used opcodes.
>> >>
>> >I think you'd only have some very trivial work here.
>> >
>> >There would be some small work to reintroduce a properly-replaceable ID
>> >table, and callbacks like ->lock() and ->unlock(), but those should be
>> >implemented in spi-nor.c sooner or later anyway.
>> >
>>
>> I am trying to modify the code to follow your recommendation. However,
>> for lock and unlock functions, i have to implement it in spi_nor.c ,
>> am i right? If yes, currently we already have existing spi_nor_lock
>> and spi_nor_unlock functions but they could not apply for my driver.
>> Should i create a new functions named altera_epcq_lock and unlock and
>> then map it to callback functions or i should the put those code
>> sunder existing spi_nor_lock/unlock?
>
> We probably want a replaceable spi_nor callback that does the
> flash-specific unlock. spi_nor_lock/unlock would then call the
> nor->unlock() / nor->lock() functions for you, when present.
> Some of the existing code should move into their own spi_nor_st_lock() /
> spi_nor_st_unlock() functions.
>
When this will be implemented? As for time being, what should i do for
these 2 functions?
>> >>>> diff --git a/Documentation/devicetree/bindings/mtd/altera_epcq.txt b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>> >>>> new file mode 100644
>> >>>> index 0000000..d14f50e
>> >>>> --- /dev/null
>> >>>> +++ b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>> >>>> @@ -0,0 +1,45 @@
>> >>>> +* MTD Altera EPCQ driver
>> >>>> +
>> >>>> +Required properties:
>> >>>> +- compatible: Should be "altr,epcq-1.0"
>> >>>> +- reg: Address and length of the register set for the device. It contains
>> >>>> + the information of registers in the same order as described by reg-names
>> >>>> +- reg-names: Should contain the reg names
>> >>>> + "csr_base": Should contain the register configuration base address
>> >>>> + "data_base": Should contain the data base address
>> >>>> +- is-epcs: boolean type.
>> >>>> + If present, the device contains EPCS flashes.
>> >>>> + Otherwise, it contains EPCQ flashes.
>> >>>> +- #address-cells: Must be <1>.
>> >>>> +- #size-cells: Must be <0>.
>> >>>> +- flash device tree subnode, there must be a node with the following fields:
>> >>>
>> >>> These subnodes definitely require a 'compatible' string. Perhaps they
>> >>> should be used to differentiate EPCS vs. EPCQ. Does "is-epcs" really
>> >>> need to be in the top-level controller node?
>> >>>
>> >>>> + - reg: Should contain the flash id
>> >>>
>> >>> Should, or must? (This question is relevant, because you seem to make it
>> >>> optional in your code.) And what does the "flash ID" mean? It seems like
>> >>> you're using as a chip-select or bank index.
>> >>>
>> Yes, this is used for chip select. It is required, not optional. This
>> to ID for each flash in the device
>
> OK, so correct the language here and enforce this in your driver. Right
> now, you don't fail gracefully if this is missing.
>
>> >>>> + if (sector_start < num_sectors-(num_sectors / 4))
>> >>>> + sr_bp = __ilog2_u32(num_sectors);
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 8))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 1;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 16))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 2;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 32))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 3;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 64))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 4;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 128))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 5;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 256))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 6;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 512))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 7;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 1024))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 8;
>> >>>> + else
>> >>>> + sr_bp = 0; /* non area protected */
>> >>>
>> >>> Yikes, that's ugly! And I'm not sure it matches the EPCQ doc I found.
>> >>> I'm pretty sure you can rewrite this if/else-if/else block in about 1
>> >>> line though.
>> >>>
>> Yes, i understand that it looks ugly. But it is the best i can do
>> since this function has to satisfy for all the supported devices
>> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf, start
>> from page 19)
>
> Did you even try? It was possible to simplify the other case, and I'm
> pretty sure this case can be simplified too. How about this? I hacked
> this together and it seems to match:
>
> if (sector_start <= num_sectors / 2)
> sr_bp = __ilog2_u32(num_sectors);
> else
> sr_bp = fls(num_sectors - 1 - sector_start) + 1;
>
>> >>>> +
>> >>>> + if (sr_bp < 0) {
>> >>>
>> >>> sr_bp is unsigned, so this is never true.
>> >>>
>> Ok. I will change to int type.
>
> Are there ever negative values?
>
>> >>>> +static int altera_epcq_probe_config_dt(struct platform_device *pdev,
>> >>>> + struct device_node *np,
>> >>>> + struct altera_epcq_plat_data *pdata)
>> >>>> +{
>> >>>> + struct device_node *pp = NULL;
>> >>>> + struct resource *epcq_res;
>> >>>> + int i = 0;
>> >>>> + u32 id;
> ...
>> >>>> + pdata->np[i] = pp;
>> >>>> +
>> >>>> + /* Read bank id from DT */
>> >>>> + if (of_get_property(pp, "reg", &id))
>
> I just realized; you're not using this correctly. of_get_property()
> returns the *length* in the third parameter, so you're not actually
> saving the bank ID here. You probably want of_property_read_u32()
> instead.
>
>> >>>
>> >>> Is this property optional? Your DT binding doc doesn't make it clear,
>> >>> but it seems like a property which would be wise to require (i.e., not
>> >>> optional).
>
> ^^^ so there should be a failure case, where you return failure if the
> property is missing.
>
>> >>>> + pdata->board_flash_info[i].bank = id;
>> >>>> + i++;
>> >>>> + }
>> >>>> + pdata->num_flashes = i;
>> >>>> + return 0;
>> >>>> +}
>
> Brian
Please ignore previous 2 emails of mine ^^
On Thu, Feb 5, 2015 at 4:37 AM, Brian Norris
<[email protected]> wrote:
> On Tue, Jan 27, 2015 at 02:53:59PM +0800, Viet Nga Dao wrote:
>> On Tue, Jan 20, 2015 at 10:05 AM, Viet Nga Dao <[email protected]> wrote:
>> > On Thu, Jan 15, 2015 at 5:27 PM, Viet Nga Dao <[email protected]> wrote:
>> >> On Tue, Jan 13, 2015 at 11:33 AM, Brian Norris
>> >> <[email protected]> wrote:
>> >>> On Thu, Dec 18, 2014 at 12:23:16AM -0800, [email protected] wrote:
>> >>>> From: Viet Nga Dao <[email protected]>
>
>> >> That is why if rewrite the drivers to follow spi-nor structure, it
>> >> will require extra decoding works for the only few used opcodes.
>> >>
>> >I think you'd only have some very trivial work here.
>> >
>> >There would be some small work to reintroduce a properly-replaceable ID
>> >table, and callbacks like ->lock() and ->unlock(), but those should be
>> >implemented in spi-nor.c sooner or later anyway.
>> >
>>
>> I am trying to modify the code to follow your recommendation. However,
>> for lock and unlock functions, i have to implement it in spi_nor.c ,
>> am i right? If yes, currently we already have existing spi_nor_lock
>> and spi_nor_unlock functions but they could not apply for my driver.
>> Should i create a new functions named altera_epcq_lock and unlock and
>> then map it to callback functions or i should the put those code
>> sunder existing spi_nor_lock/unlock?
>
> We probably want a replaceable spi_nor callback that does the
> flash-specific unlock. spi_nor_lock/unlock would then call the
> nor->unlock() / nor->lock() functions for you, when present.
> Some of the existing code should move into their own spi_nor_st_lock() /
> spi_nor_st_unlock() functions.
>
This changes will be made by me or maintainers? If current this
functions are not supported, i decide not to implement my lock, unlock
function as well.
>> >>>> diff --git a/Documentation/devicetree/bindings/mtd/altera_epcq.txt b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>> >>>> new file mode 100644
>> >>>> index 0000000..d14f50e
>> >>>> --- /dev/null
>> >>>> +++ b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>> >>>> @@ -0,0 +1,45 @@
>> >>>> +* MTD Altera EPCQ driver
>> >>>> +
>> >>>> +Required properties:
>> >>>> +- compatible: Should be "altr,epcq-1.0"
>> >>>> +- reg: Address and length of the register set for the device. It contains
>> >>>> + the information of registers in the same order as described by reg-names
>> >>>> +- reg-names: Should contain the reg names
>> >>>> + "csr_base": Should contain the register configuration base address
>> >>>> + "data_base": Should contain the data base address
>> >>>> +- is-epcs: boolean type.
>> >>>> + If present, the device contains EPCS flashes.
>> >>>> + Otherwise, it contains EPCQ flashes.
>> >>>> +- #address-cells: Must be <1>.
>> >>>> +- #size-cells: Must be <0>.
>> >>>> +- flash device tree subnode, there must be a node with the following fields:
>> >>>
>> >>> These subnodes definitely require a 'compatible' string. Perhaps they
>> >>> should be used to differentiate EPCS vs. EPCQ. Does "is-epcs" really
>> >>> need to be in the top-level controller node?
>> >>>
>> >>>> + - reg: Should contain the flash id
>> >>>
>> >>> Should, or must? (This question is relevant, because you seem to make it
>> >>> optional in your code.) And what does the "flash ID" mean? It seems like
>> >>> you're using as a chip-select or bank index.
>> >>>
>> Yes, this is used for chip select. It is required, not optional. This
>> to ID for each flash in the device
>
> OK, so correct the language here and enforce this in your driver. Right
> now, you don't fail gracefully if this is missing.
>
Sorry, you are right. This field is unnecessary for my driver.
Instead, compatible is replaced. I will update it with 2nd version.
>> >>>> + if (sector_start < num_sectors-(num_sectors / 4))
>> >>>> + sr_bp = __ilog2_u32(num_sectors);
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 8))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 1;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 16))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 2;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 32))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 3;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 64))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 4;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 128))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 5;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 256))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 6;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 512))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 7;
>> >>>> + else if (sector_start < num_sectors-(num_sectors / 1024))
>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 8;
>> >>>> + else
>> >>>> + sr_bp = 0; /* non area protected */
>> >>>
>> >>> Yikes, that's ugly! And I'm not sure it matches the EPCQ doc I found.
>> >>> I'm pretty sure you can rewrite this if/else-if/else block in about 1
>> >>> line though.
>> >>>
>> Yes, i understand that it looks ugly. But it is the best i can do
>> since this function has to satisfy for all the supported devices
>> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf, start
>> from page 19)
>
> Did you even try? It was possible to simplify the other case, and I'm
> pretty sure this case can be simplified too. How about this? I hacked
> this together and it seems to match:
>
> if (sector_start <= num_sectors / 2)
> sr_bp = __ilog2_u32(num_sectors);
> else
> sr_bp = fls(num_sectors - 1 - sector_start) + 1;
>
Umm. This does not seem right to me. Just look at sector_start <
number_sector / 2. From the altera EPCQ datasheet
(http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf), such as
EPCQ16 (page 19,20). Sector start <number_sector/2 is the case where
TB = 1 (table 17). In this table we have few options and sr_bp =
__ilog2_u32(num_sectors) is only cover for the sector from 0 to 15 to
be protected.
>> >>>> +
>> >>>> + if (sr_bp < 0) {
>> >>>
>> >>> sr_bp is unsigned, so this is never true.
>> >>>
>> Ok. I will change to int type.
>
> Are there ever negative values?
>
>> >>>> +static int altera_epcq_probe_config_dt(struct platform_device *pdev,
>> >>>> + struct device_node *np,
>> >>>> + struct altera_epcq_plat_data *pdata)
>> >>>> +{
>> >>>> + struct device_node *pp = NULL;
>> >>>> + struct resource *epcq_res;
>> >>>> + int i = 0;
>> >>>> + u32 id;
> ...
>> >>>> + pdata->np[i] = pp;
>> >>>> +
>> >>>> + /* Read bank id from DT */
>> >>>> + if (of_get_property(pp, "reg", &id))
>
> I just realized; you're not using this correctly. of_get_property()
> returns the *length* in the third parameter, so you're not actually
> saving the bank ID here. You probably want of_property_read_u32()
> instead.
>
I will remove this since it is unnecessary.
>> >>>
>> >>> Is this property optional? Your DT binding doc doesn't make it clear,
>> >>> but it seems like a property which would be wise to require (i.e., not
>> >>> optional).
>
> ^^^ so there should be a failure case, where you return failure if the
> property is missing.
>
>> >>>> + pdata->board_flash_info[i].bank = id;
>> >>>> + i++;
>> >>>> + }
>> >>>> + pdata->num_flashes = i;
>> >>>> + return 0;
>> >>>> +}
>
> Brian
Sorry for multiple emails.
On Mon, Feb 9, 2015 at 2:42 PM, Viet Nga Dao <[email protected]> wrote:
> Please ignore previous 2 emails of mine ^^
>
> On Thu, Feb 5, 2015 at 4:37 AM, Brian Norris
> <[email protected]> wrote:
>> On Tue, Jan 27, 2015 at 02:53:59PM +0800, Viet Nga Dao wrote:
>>> On Tue, Jan 20, 2015 at 10:05 AM, Viet Nga Dao <[email protected]> wrote:
>>> > On Thu, Jan 15, 2015 at 5:27 PM, Viet Nga Dao <[email protected]> wrote:
>>> >> On Tue, Jan 13, 2015 at 11:33 AM, Brian Norris
>>> >> <[email protected]> wrote:
>>> >>> On Thu, Dec 18, 2014 at 12:23:16AM -0800, [email protected] wrote:
>>> >>>> From: Viet Nga Dao <[email protected]>
>>
>>> >> That is why if rewrite the drivers to follow spi-nor structure, it
>>> >> will require extra decoding works for the only few used opcodes.
>>> >>
>>> >I think you'd only have some very trivial work here.
>>> >
>>> >There would be some small work to reintroduce a properly-replaceable ID
>>> >table, and callbacks like ->lock() and ->unlock(), but those should be
>>> >implemented in spi-nor.c sooner or later anyway.
>>> >
>>>
>>> I am trying to modify the code to follow your recommendation. However,
>>> for lock and unlock functions, i have to implement it in spi_nor.c ,
>>> am i right? If yes, currently we already have existing spi_nor_lock
>>> and spi_nor_unlock functions but they could not apply for my driver.
>>> Should i create a new functions named altera_epcq_lock and unlock and
>>> then map it to callback functions or i should the put those code
>>> sunder existing spi_nor_lock/unlock?
>>
>> We probably want a replaceable spi_nor callback that does the
>> flash-specific unlock. spi_nor_lock/unlock would then call the
>> nor->unlock() / nor->lock() functions for you, when present.
>> Some of the existing code should move into their own spi_nor_st_lock() /
>> spi_nor_st_unlock() functions.
>>
>
> This changes will be made by me or maintainers? If current this
> functions are not supported, i decide not to implement my lock, unlock
> function as well.
>
I made the changes at my side here. However, there are something i
want to confirm with you:
- in spi-nor.h, i add 2 functions. _lock and _unlock instead of lock
and unlock. It is because we already have struct mutex lock with the
same name.
int (*_lock)(struct spi_nor *nor, loff_t offs, uint64_t len);
int (*_unlock)(struct spi_nor *nor, loff_t offs, uint64_t len);
- in spi-nor.c, i change the current spi_nor_lock and spi_nor_unlock
to stmicro_spi_nor_lock and stmirco_spi_nor_unlock
- in spi-nor.c, i add 2 functions:
static int spi_nor_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct spi_nor *nor = mtd_to_spi_nor(mtd);
int ret = 0;
ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK);
if (ret)
return ret;
/* Wait until finished previous command */
ret = wait_till_ready(nor);
if (ret)
goto err;
ret = nor->_lock(nor, ofs, len);
err:
spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
return ret;
}
static int spi_nor_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct spi_nor *nor = mtd_to_spi_nor(mtd);
int ret = 0;
ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_LOCK);
if (ret)
return ret;
/* Wait until finished previous command */
ret = wait_till_ready(nor);
if (ret)
goto err;
ret = nor->_unlock(nor, ofs, len);
err:
spi_nor_unlock_and_unprep(nor, SPI_NOR_OPS_LOCK);
return ret;
}
- Then under spi_nor_scan function, i add these few lines:
/* nor protection support for STmicro chips */
if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST) {
mtd->_lock = stmicro_spi_nor_lock;
mtd->_unlock = stmicro_spi_nor_unlock;
} else {
mtd->_lock = spi_nor_lock;
mtd->_unlock = spi_nor_unlock;
}
What is your comment?
>>> >>>> diff --git a/Documentation/devicetree/bindings/mtd/altera_epcq.txt b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>>> >>>> new file mode 100644
>>> >>>> index 0000000..d14f50e
>>> >>>> --- /dev/null
>>> >>>> +++ b/Documentation/devicetree/bindings/mtd/altera_epcq.txt
>>> >>>> @@ -0,0 +1,45 @@
>>> >>>> +* MTD Altera EPCQ driver
>>> >>>> +
>>> >>>> +Required properties:
>>> >>>> +- compatible: Should be "altr,epcq-1.0"
>>> >>>> +- reg: Address and length of the register set for the device. It contains
>>> >>>> + the information of registers in the same order as described by reg-names
>>> >>>> +- reg-names: Should contain the reg names
>>> >>>> + "csr_base": Should contain the register configuration base address
>>> >>>> + "data_base": Should contain the data base address
>>> >>>> +- is-epcs: boolean type.
>>> >>>> + If present, the device contains EPCS flashes.
>>> >>>> + Otherwise, it contains EPCQ flashes.
>>> >>>> +- #address-cells: Must be <1>.
>>> >>>> +- #size-cells: Must be <0>.
>>> >>>> +- flash device tree subnode, there must be a node with the following fields:
>>> >>>
>>> >>> These subnodes definitely require a 'compatible' string. Perhaps they
>>> >>> should be used to differentiate EPCS vs. EPCQ. Does "is-epcs" really
>>> >>> need to be in the top-level controller node?
>>> >>>
>>> >>>> + - reg: Should contain the flash id
>>> >>>
>>> >>> Should, or must? (This question is relevant, because you seem to make it
>>> >>> optional in your code.) And what does the "flash ID" mean? It seems like
>>> >>> you're using as a chip-select or bank index.
>>> >>>
>>> Yes, this is used for chip select. It is required, not optional. This
>>> to ID for each flash in the device
>>
>> OK, so correct the language here and enforce this in your driver. Right
>> now, you don't fail gracefully if this is missing.
>>
>
> Sorry, you are right. This field is unnecessary for my driver.
> Instead, compatible is replaced. I will update it with 2nd version.
>
>>> >>>> + if (sector_start < num_sectors-(num_sectors / 4))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors);
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 8))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 1;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 16))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 2;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 32))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 3;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 64))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 4;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 128))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 5;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 256))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 6;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 512))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 7;
>>> >>>> + else if (sector_start < num_sectors-(num_sectors / 1024))
>>> >>>> + sr_bp = __ilog2_u32(num_sectors) - 8;
>>> >>>> + else
>>> >>>> + sr_bp = 0; /* non area protected */
>>> >>>
>>> >>> Yikes, that's ugly! And I'm not sure it matches the EPCQ doc I found.
>>> >>> I'm pretty sure you can rewrite this if/else-if/else block in about 1
>>> >>> line though.
>>> >>>
>>> Yes, i understand that it looks ugly. But it is the best i can do
>>> since this function has to satisfy for all the supported devices
>>> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf, start
>>> from page 19)
>>
>> Did you even try? It was possible to simplify the other case, and I'm
>> pretty sure this case can be simplified too. How about this? I hacked
>> this together and it seems to match:
>>
>> if (sector_start <= num_sectors / 2)
>> sr_bp = __ilog2_u32(num_sectors);
>> else
>> sr_bp = fls(num_sectors - 1 - sector_start) + 1;
>>
>
> Umm. This does not seem right to me. Just look at sector_start <
> number_sector / 2. From the altera EPCQ datasheet
> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf), such as
> EPCQ16 (page 19,20). Sector start <number_sector/2 is the case where
> TB = 1 (table 17). In this table we have few options and sr_bp =
> __ilog2_u32(num_sectors) is only cover for the sector from 0 to 15 to
> be protected.
>
I think the code should be like this:
if (sector_start >= num_sectors / 2)
sr_bp = fls(num_sectors - 1 - sector_start) + 1;
else if ((sector_end < num_sectors / 2)
sr_bp = fls(sector_end) + 1;
else
sr_bp = 16; /* lock all areas */
>>> >>>> +
>>> >>>> + if (sr_bp < 0) {
>>> >>>
>>> >>> sr_bp is unsigned, so this is never true.
>>> >>>
>>> Ok. I will change to int type.
>>
>> Are there ever negative values?
>>
>>> >>>> +static int altera_epcq_probe_config_dt(struct platform_device *pdev,
>>> >>>> + struct device_node *np,
>>> >>>> + struct altera_epcq_plat_data *pdata)
>>> >>>> +{
>>> >>>> + struct device_node *pp = NULL;
>>> >>>> + struct resource *epcq_res;
>>> >>>> + int i = 0;
>>> >>>> + u32 id;
>> ...
>>> >>>> + pdata->np[i] = pp;
>>> >>>> +
>>> >>>> + /* Read bank id from DT */
>>> >>>> + if (of_get_property(pp, "reg", &id))
>>
>> I just realized; you're not using this correctly. of_get_property()
>> returns the *length* in the third parameter, so you're not actually
>> saving the bank ID here. You probably want of_property_read_u32()
>> instead.
>>
>
> I will remove this since it is unnecessary.
>
>>> >>>
>>> >>> Is this property optional? Your DT binding doc doesn't make it clear,
>>> >>> but it seems like a property which would be wise to require (i.e., not
>>> >>> optional).
>>
>> ^^^ so there should be a failure case, where you return failure if the
>> property is missing.
>>
>>> >>>> + pdata->board_flash_info[i].bank = id;
>>> >>>> + i++;
>>> >>>> + }
>>> >>>> + pdata->num_flashes = i;
>>> >>>> + return 0;
>>> >>>> +}
>>
>> Brian