Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753330AbaLJBdZ (ORCPT ); Tue, 9 Dec 2014 20:33:25 -0500 Received: from mail-pd0-f172.google.com ([209.85.192.172]:65443 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750952AbaLJBdW (ORCPT ); Tue, 9 Dec 2014 20:33:22 -0500 Message-ID: <5487A2D6.8070901@gmail.com> Date: Wed, 10 Dec 2014 07:03:10 +0530 From: Varka Bhadram User-Agent: Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Ray Jui , Wolfram Sang , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Grant Likely , Christian Daudt , Matt Porter , Florian Fainelli , Russell King CC: Scott Branden , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, devicetree@vger.kernel.org Subject: Re: [PATCH 2/4] i2c: iproc: Add Broadcom iProc I2C Driver References: <1418172891-19441-1-git-send-email-rjui@broadcom.com> <1418172891-19441-3-git-send-email-rjui@broadcom.com> In-Reply-To: <1418172891-19441-3-git-send-email-rjui@broadcom.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 10 December 2014 06:24 AM, Ray Jui wrote: > Add initial support to the Broadcom iProc I2C controller found in the > iProc family of SoCs. > > The iProc I2C controller has separate internal TX and RX FIFOs, each has > a size of 64 bytes. The iProc I2C controller supports two bus speeds > including standard mode (100kHz) and fast mode (400kHz) > > Signed-off-by: Ray Jui > Reviewed-by: Scott Branden > --- > drivers/i2c/busses/Kconfig | 9 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-bcm-iproc.c | 503 ++++++++++++++++++++++++++++++++++++ > 3 files changed, 513 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-bcm-iproc.c > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index c1351d9..8a2eb7e 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -372,6 +372,15 @@ config I2C_BCM2835 > This support is also available as a module. If so, the module > will be called i2c-bcm2835. > > +config I2C_BCM_IPROC > + tristate "Broadcom iProc I2C controller" > + depends on ARCH_BCM_IPROC > + help > + If you say yes to this option, support will be included for the > + Broadcom iProc I2C controller. > + > + If you don't know what to do here, say N. > + > config I2C_BCM_KONA > tristate "BCM Kona I2C adapter" > depends on ARCH_BCM_MOBILE > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 5e6c822..216e7be 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -33,6 +33,7 @@ obj-$(CONFIG_I2C_AT91) += i2c-at91.o > obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o > obj-$(CONFIG_I2C_AXXIA) += i2c-axxia.o > obj-$(CONFIG_I2C_BCM2835) += i2c-bcm2835.o > +obj-$(CONFIG_I2C_BCM_IPROC) += i2c-bcm-iproc.o > obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o > obj-$(CONFIG_I2C_CADENCE) += i2c-cadence.o > obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o > diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c > new file mode 100644 > index 0000000..0e6e603 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-bcm-iproc.c > @@ -0,0 +1,503 @@ > +/* > + * Copyright (C) 2014 Broadcom Corporation > + * > + * 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 version 2. > + * > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any > + * kind, whether express or implied; without even the implied warranty > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define CFG_OFFSET 0x00 > +#define CFG_RESET_SHIFT 31 > +#define CFG_EN_SHIFT 30 > +#define CFG_M_RETRY_CNT_SHIFT 16 > +#define CFG_M_RETRY_CNT_MASK 0x0f > + > +#define TIM_CFG_OFFSET 0x04 > +#define TIME_CFG_MODE_400_SHIFT 31 > + > +#define M_FIFO_CTRL_OFFSET 0x0c > +#define M_FIFO_RX_FLUSH_SHIFT 31 > +#define M_FIFO_TX_FLUSH_SHIFT 30 > +#define M_FIFO_RX_CNT_SHIFT 16 > +#define M_FIFO_RX_CNT_MASK 0x7f > +#define M_FIFO_RX_THLD_SHIFT 8 > +#define M_FIFO_RX_THLD_MASK 0x3f > + > +#define M_CMD_OFFSET 0x30 > +#define M_CMD_START_BUSY_SHIFT 31 > +#define M_CMD_STATUS_SHIFT 25 > +#define M_CMD_STATUS_MASK 0x07 > +#define M_CMD_STATUS_SUCCESS 0x0 > +#define M_CMD_STATUS_LOST_ARB 0x1 > +#define M_CMD_STATUS_NACK_ADDR 0x2 > +#define M_CMD_STATUS_NACK_DATA 0x3 > +#define M_CMD_STATUS_TIMEOUT 0x4 > +#define M_CMD_PROTOCOL_SHIFT 9 > +#define M_CMD_PROTOCOL_MASK 0xf > +#define M_CMD_PROTOCOL_BLK_WR 0x7 > +#define M_CMD_PROTOCOL_BLK_RD 0x8 > +#define M_CMD_PEC_SHIFT 8 > +#define M_CMD_RD_CNT_SHIFT 0 > +#define M_CMD_RD_CNT_MASK 0xff > + > +#define IE_OFFSET 0x38 > +#define IE_M_RX_FIFO_FULL_SHIFT 31 > +#define IE_M_RX_THLD_SHIFT 30 > +#define IE_M_START_BUSY_SHIFT 28 > + > +#define IS_OFFSET 0x3c > +#define IS_M_RX_FIFO_FULL_SHIFT 31 > +#define IS_M_RX_THLD_SHIFT 30 > +#define IS_M_START_BUSY_SHIFT 28 > + > +#define M_TX_OFFSET 0x40 > +#define M_TX_WR_STATUS_SHIFT 31 > +#define M_TX_DATA_SHIFT 0 > +#define M_TX_DATA_MASK 0xff > + > +#define M_RX_OFFSET 0x44 > +#define M_RX_STATUS_SHIFT 30 > +#define M_RX_STATUS_MASK 0x03 > +#define M_RX_PEC_ERR_SHIFT 29 > +#define M_RX_DATA_SHIFT 0 > +#define M_RX_DATA_MASK 0xff > + > +#define I2C_TIMEOUT_MESC 100 > +#define M_TX_RX_FIFO_SIZE 64 > + > +enum bus_speed_index { > + I2C_SPD_100K = 0, > + I2C_SPD_400K, > +}; > + > +struct bcm_iproc_i2c_dev { > + struct device *device; > + > + void __iomem *base; > + struct i2c_msg *msg; > + > + struct i2c_adapter adapter; > + > + struct completion done; > +}; > + > +/* > + * Can be expanded in the future if more interrupt status bits are utilized > + */ > +#define ISR_MASK (1 << IS_M_START_BUSY_SHIFT) > + > +static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data) > +{ > + struct bcm_iproc_i2c_dev *dev = data; > + u32 status = readl(dev->base + IS_OFFSET); > + > + status &= ISR_MASK; > + > + if (!status) > + return IRQ_NONE; > + > + writel(status, dev->base + IS_OFFSET); > + complete_all(&dev->done); > + > + return IRQ_HANDLED; > +} > + > +static int __wait_for_bus_idle(struct bcm_iproc_i2c_dev *dev) > +{ > + unsigned long timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT_MESC); > + > + while (readl(dev->base + M_CMD_OFFSET) & > + (1 << M_CMD_START_BUSY_SHIFT)) { > + if (time_after(jiffies, timeout)) { > + dev_err(dev->device, "wait for bus idle timeout\n"); > + return -ETIMEDOUT; > + } > + } > + > + return 0; > +} > + > +static int bcm_iproc_i2c_format_addr(struct bcm_iproc_i2c_dev *dev, > + struct i2c_msg *msg, u8 *addr) > +{ Match open parenthesis.. static int bcm_iproc_i2c_format_addr(struct bcm_iproc_i2c_dev *dev, struct i2c_msg *msg, u8 *addr) > + > + if (msg->flags & I2C_M_TEN) { > + dev_err(dev->device, "no support for 10-bit address\n"); > + return -EINVAL; > + } > + > + *addr = (msg->addr << 1) & 0xfe; > + > + if (msg->flags & I2C_M_RD) > + *addr |= 1; > + > + return 0; > +} > + > +static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *dev) > +{ > + u32 val; > + > + val = readl(dev->base + M_CMD_OFFSET); > + val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK; > + > + switch (val) { > + case M_CMD_STATUS_SUCCESS: > + return 0; > + > + case M_CMD_STATUS_LOST_ARB: > + dev_err(dev->device, "lost bus arbitration\n"); > + return -EREMOTEIO; > + > + case M_CMD_STATUS_NACK_ADDR: > + dev_err(dev->device, "NAK addr:0x%02x\n", dev->msg->addr); > + return -EREMOTEIO; > + > + case M_CMD_STATUS_NACK_DATA: > + dev_err(dev->device, "NAK data\n"); > + return -EREMOTEIO; > + > + case M_CMD_STATUS_TIMEOUT: > + dev_err(dev->device, "bus timeout\n"); > + return -ETIMEDOUT; > + > + default: > + dev_err(dev->device, "unknown error code=%d\n", val); > + return -EREMOTEIO; > + } > + > + return -EREMOTEIO; > +} > + > +static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *dev, > + struct i2c_msg *msg) > +{ dto... > + int ret, i; > + u8 addr; > + u32 val; > + unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MESC); > + > + if (msg->len < 1 || msg->len > M_TX_RX_FIFO_SIZE - 1) { > + dev_err(dev->device, > + "supported data length is 1 - %u bytes\n", > + M_TX_RX_FIFO_SIZE - 1); > + return -EINVAL; > + } > + > + dev->msg = msg; > + ret = __wait_for_bus_idle(dev); > + if (ret) > + return ret; > + > + ret = bcm_iproc_i2c_format_addr(dev, msg, &addr); > + if (ret) > + return ret; > + > + /* load slave address into the TX FIFO */ > + writel(addr, dev->base + M_TX_OFFSET); > + > + /* for a write transaction, load data into the TX FIFO */ > + if (!(msg->flags & I2C_M_RD)) { > + for (i = 0; i < msg->len; i++) { > + val = msg->buf[i]; > + > + /* mark the last byte */ > + if (i == msg->len - 1) > + val |= 1 << M_TX_WR_STATUS_SHIFT; > + > + writel(val, dev->base + M_TX_OFFSET); > + } > + } > + > + /* mark as incomplete before starting the transaction */ > + reinit_completion(&dev->done); > + > + /* > + * Enable the "start busy" interrupt, which will be triggered after > + * the transaction is done > + */ > + writel(1 << IE_M_START_BUSY_SHIFT, dev->base + IE_OFFSET); > + > + /* > + * Now we can activate the transfer. For a read operation, specify the > + * number of bytes to read > + */ > + val = 1 << M_CMD_START_BUSY_SHIFT; > + if (msg->flags & I2C_M_RD) { > + val |= (M_CMD_PROTOCOL_BLK_RD << M_CMD_PROTOCOL_SHIFT) | > + (msg->len << M_CMD_RD_CNT_SHIFT); > + } else { > + val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT); > + } > + writel(val, dev->base + M_CMD_OFFSET); > + > + time_left = wait_for_completion_timeout(&dev->done, time_left); > + > + /* disable all interrupts */ > + writel(0, dev->base + IE_OFFSET); > + > + if (!time_left) { > + dev_err(dev->device, "transaction times out\n"); > + > + /* flush FIFOs */ > + val = (1 << M_FIFO_RX_FLUSH_SHIFT) | > + (1 << M_FIFO_TX_FLUSH_SHIFT); > + writel(val, dev->base + M_FIFO_CTRL_OFFSET); > + return -EREMOTEIO; > + } > + > + ret = bcm_iproc_i2c_check_status(dev); > + if (ret) { > + /* flush both TX/RX FIFOs */ > + val = (1 << M_FIFO_RX_FLUSH_SHIFT) | > + (1 << M_FIFO_TX_FLUSH_SHIFT); > + writel(val, dev->base + M_FIFO_CTRL_OFFSET); > + return ret; > + } > + > + /* > + * For a read operation, we now need to load the data from FIFO > + * into the memory buffer > + */ > + if (msg->flags & I2C_M_RD) { > + for (i = 0; i < msg->len; i++) { > + msg->buf[i] = (readl(dev->base + M_RX_OFFSET) >> > + M_RX_DATA_SHIFT) & M_RX_DATA_MASK; > + } > + } > + > + dev_dbg(dev->device, "xfer %c, addr=0x%02x, len=%d\n", > + (msg->flags & I2C_M_RD) ? 'R' : 'W', msg->addr, > + msg->len); > + dev_dbg(dev->device, "**** data start ****\n"); > + for (i = 0; i < msg->len; i++) > + dev_dbg(dev->device, "0x%02x ", msg->buf[i]); > + dev_dbg(dev->device, "**** data end ****\n"); > + > + return 0; > +} > + > +static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter, > + struct i2c_msg msgs[], int num) > +{ > + struct bcm_iproc_i2c_dev *dev = i2c_get_adapdata(adapter); > + int ret, i; > + > + /* go through all messages */ > + for (i = 0; i < num; i++) { > + ret = bcm_iproc_i2c_xfer_single_msg(dev, &msgs[i]); > + if (ret) { > + dev_err(dev->device, "xfer failed\n"); > + return ret; > + } > + } > + > + return num; > +} > + > +static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; > +} > + > +static const struct i2c_algorithm bcm_iproc_algo = { > + .master_xfer = bcm_iproc_i2c_xfer, > + .functionality = bcm_iproc_i2c_functionality, > +}; > + > +static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *dev) > +{ > + unsigned int bus_speed, speed_bit; > + u32 val; > + int ret = of_property_read_u32(dev->device->of_node, "clock-frequency", > + &bus_speed); > + if (ret < 0) { > + dev_err(dev->device, "missing clock-frequency property\n"); > + return -ENODEV; > + } > + > + switch (bus_speed) { > + case 100000: > + speed_bit = 0; > + break; > + case 400000: > + speed_bit = 1; > + break; > + default: > + dev_err(dev->device, "%d Hz bus speed not supported\n", > + bus_speed); > + dev_err(dev->device, "valid speeds are 100khz and 400khz\n"); > + return -EINVAL; > + } > + > + val = readl(dev->base + TIM_CFG_OFFSET); > + val &= ~(1 << TIME_CFG_MODE_400_SHIFT); > + val |= speed_bit << TIME_CFG_MODE_400_SHIFT; > + writel(val, dev->base + TIM_CFG_OFFSET); > + > + dev_info(dev->device, "bus set to %u Hz\n", bus_speed); > + > + return 0; > +} > + > +static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *dev) > +{ > + u32 val; > + > + /* put controller in reset */ > + val = readl(dev->base + CFG_OFFSET); > + val |= 1 << CFG_RESET_SHIFT; > + val &= ~(1 << CFG_EN_SHIFT); > + writel(val, dev->base + CFG_OFFSET); > + > + /* wait 100 usec per spec */ > + udelay(100); > + > + /* bring controller out of reset */ > + val = readl(dev->base + CFG_OFFSET); > + val &= ~(1 << CFG_RESET_SHIFT); > + writel(val, dev->base + CFG_OFFSET); > + > + /* flush TX/RX FIFOs and set RX FIFO threshold to zero */ > + val = (1 << M_FIFO_RX_FLUSH_SHIFT) | (1 << M_FIFO_TX_FLUSH_SHIFT); > + writel(val, dev->base + M_FIFO_CTRL_OFFSET); > + > + /* disable all interrupts */ > + val = 0; > + writel(val, dev->base + IE_OFFSET); > + > + /* clear all pending interrupts */ > + val = readl(dev->base + IS_OFFSET); > + writel(val, dev->base + IS_OFFSET); > + > + return 0; > +} > + > +static void bcm_iproc_i2c_enable(struct bcm_iproc_i2c_dev *dev) > +{ > + u32 val; > + > + val = readl(dev->base + CFG_OFFSET); > + val |= 1 << CFG_EN_SHIFT; > + writel(val, dev->base + CFG_OFFSET); > +} > + > +static void bcm_iproc_i2c_disable(struct bcm_iproc_i2c_dev *dev) > +{ > + u32 val; > + > + val = readl(dev->base + CFG_OFFSET); > + val &= ~(1 << CFG_EN_SHIFT); > + writel(val, dev->base + CFG_OFFSET); > +} > + > +static int bcm_iproc_i2c_probe(struct platform_device *pdev) > +{ > + int irq, ret = 0; > + struct bcm_iproc_i2c_dev *dev; > + struct i2c_adapter *adap; > + struct resource *res; > + > + dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); > + if (!dev) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, dev); > + dev->device = &pdev->dev; > + init_completion(&dev->done); > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) > + return -ENODEV; We can remove this resource check. This checking will happen with devm_ioremap_resource() > + dev->base = devm_ioremap_resource(dev->device, res); > + if (IS_ERR(dev->base)) > + return -ENOMEM; > + > + ret = bcm_iproc_i2c_init(dev); > + if (ret) > + return ret; > + > + ret = bcm_iproc_i2c_cfg_speed(dev); > + if (ret) > + return ret; > + > + irq = platform_get_irq(pdev, 0); > + if (irq < 0) { > + dev_err(dev->device, "no irq resource\n"); > + return irq; > + } > + > + ret = devm_request_irq(&pdev->dev, irq, bcm_iproc_i2c_isr, > + IRQF_SHARED, pdev->name, dev); > + if (ret) { > + dev_err(dev->device, "unable to request irq %i\n", irq); > + return ret; > + } > + > + bcm_iproc_i2c_enable(dev); > + > + adap = &dev->adapter; > + i2c_set_adapdata(adap, dev); > + strlcpy(adap->name, "Broadcom iProc I2C adapter", sizeof(adap->name)); > + adap->algo = &bcm_iproc_algo; > + adap->dev.parent = &pdev->dev; > + adap->dev.of_node = pdev->dev.of_node; > + > + ret = i2c_add_adapter(adap); > + if (ret) { > + dev_err(dev->device, "failed to add adapter\n"); > + return ret; > + } > + > + dev_info(dev->device, "device registered successfully\n"); > + > + return 0; > +} > + > +static int bcm_iproc_i2c_remove(struct platform_device *pdev) > +{ > + struct bcm_iproc_i2c_dev *dev = platform_get_drvdata(pdev); > + > + i2c_del_adapter(&dev->adapter); > + bcm_iproc_i2c_disable(dev); > + > + return 0; > +} > + > +static const struct of_device_id bcm_iproc_i2c_of_match[] = { > + {.compatible = "brcm,iproc-i2c",}, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match); > + > +static struct platform_driver bcm_iproc_i2c_driver = { > + .driver = { > + .name = "bcm-iproc-i2c", > + .owner = THIS_MODULE, No need to update this field. Its updated by module_platform_driver(). > + .of_match_table = bcm_iproc_i2c_of_match, > + }, > + .probe = bcm_iproc_i2c_probe, > + .remove = bcm_iproc_i2c_remove, > +}; > +module_platform_driver(bcm_iproc_i2c_driver); > + > +MODULE_AUTHOR("Ray Jui "); > +MODULE_DESCRIPTION("Broadcom iProc I2C Driver"); > +MODULE_LICENSE("GPL v2"); -- Thanks and Regards, Varka Bhadram. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/