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Message-ID: <CAHfPSqDUziJOisH6TvFBOoy590txinMGXceaT7cMCyakVM-X7Q@mail.gmail.com>
Date: Tue, 15 Jan 2013 11:53:56 +0530
From: Naveen Krishna Ch <naveenkrishna.ch@...il.com>
To: linux-i2c@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org,
linux-samsung-soc@...r.kernel.org, kgene.kim@...sung.com,
grant.likely@...retlab.ca, w.sang@...gutronix.de,
linux-kernel@...r.kernel.org, taeggyun.ko@...sung.com,
balbi@...com, thomas.abraham@...aro.org
Subject: Re: [PATCH v3] i2c: exynos5: add High Speed I2C controller driver
On 28 December 2012 22:06, Naveen Krishna Ch <naveenkrishna.ch@...il.com> wrote:
> On 28 December 2012 16:57, Naveen Krishna Chatradhi
> <ch.naveen@...sung.com> wrote:
>> Adds support for High Speed I2C driver found in Exynos5 and later
>> SoCs from Samsung. This driver currently supports Auto mode.
>>
>> Driver only supports Device Tree method of passing platform data.
>> Note: Added debugfs support for registers view, not tested.
>>
>> Signed-off-by: Taekgyun Ko <taeggyun.ko@...sung.com>
>> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@...sung.com>
>> ---
>> Changes since v2: fixed comments from Felipe Balbi.
>> And minor fixes for the return values in exynos5_i2c_doxfer()
>>
>> drivers/i2c/busses/Kconfig | 7 +
>> drivers/i2c/busses/Makefile | 1 +
>> drivers/i2c/busses/i2c-exynos5.c | 736 ++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 744 insertions(+)
>> create mode 100644 drivers/i2c/busses/i2c-exynos5.c
>>
>> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
>> index bdca511..4caea76 100644
>> --- a/drivers/i2c/busses/Kconfig
>> +++ b/drivers/i2c/busses/Kconfig
>> @@ -618,6 +618,13 @@ config I2C_S3C2410
>> Say Y here to include support for I2C controller in the
>> Samsung SoCs.
>>
>> +config I2C_EXYNOS5
>> + tristate "Exynos5 high-speed I2C driver"
>> + depends on ARCH_EXYNOS5
>> + help
>> + Say Y here to include support for High-speed I2C controller in the
>> + Exynos5 based Samsung SoCs.
>> +
>> config I2C_S6000
>> tristate "S6000 I2C support"
>> depends on XTENSA_VARIANT_S6000
>> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
>> index 6181f3f..4b1548c 100644
>> --- a/drivers/i2c/busses/Makefile
>> +++ b/drivers/i2c/busses/Makefile
>> @@ -61,6 +61,7 @@ obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o
>> obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
>> obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o
>> obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
>> +obj-$(CONFIG_I2C_EXYNOS5) += i2c-exynos5.o
>> obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
>> obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
>> obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
>> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
>> new file mode 100644
>> index 0000000..a5eb959
>> --- /dev/null
>> +++ b/drivers/i2c/busses/i2c-exynos5.c
>> @@ -0,0 +1,736 @@
>> +/**
>> + * i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver
>> + *
>> + * Copyright (C) 2012 Samsung Electronics Co., Ltd.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> +*/
>> +
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/debugfs.h>
>> +
>> +#include <linux/i2c.h>
>> +#include <linux/init.h>
>> +#include <linux/time.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/delay.h>
>> +#include <linux/errno.h>
>> +#include <linux/err.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/clk.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/of_i2c.h>
>> +
>> +/* Register Map */
>> +#define HSI2C_CTL 0x00
>> +#define HSI2C_FIFO_CTL 0x04
>> +#define HSI2C_TRAILIG_CTL 0x08
>> +#define HSI2C_CLK_CTL 0x0C
>> +#define HSI2C_CLK_SLOT 0x10
>> +#define HSI2C_INT_ENABLE 0x20
>> +#define HSI2C_INT_STATUS 0x24
>> +#define HSI2C_ERR_STATUS 0x2C
>> +#define HSI2C_FIFO_STATUS 0x30
>> +#define HSI2C_TX_DATA 0x34
>> +#define HSI2C_RX_DATA 0x38
>> +#define HSI2C_CONF 0x40
>> +#define HSI2C_AUTO_CONF 0x44
>> +#define HSI2C_TIMEOUT 0x48
>> +#define HSI2C_MANUAL_CMD 0x4C
>> +#define HSI2C_TRANS_STATUS 0x50
>> +#define HSI2C_TIMING_HS1 0x54
>> +#define HSI2C_TIMING_HS2 0x58
>> +#define HSI2C_TIMING_HS3 0x5C
>> +#define HSI2C_TIMING_FS1 0x60
>> +#define HSI2C_TIMING_FS2 0x64
>> +#define HSI2C_TIMING_FS3 0x68
>> +#define HSI2C_TIMING_SLA 0x6C
>> +#define HSI2C_ADDR 0x70
>> +
>> +/* I2C_CTL Register bits */
>> +#define HSI2C_FUNC_MODE_I2C (1u << 0)
>> +#define HSI2C_MASTER (1u << 3)
>> +#define HSI2C_RXCHON (1u << 6)
>> +#define HSI2C_TXCHON (1u << 7)
>> +#define HSI2C_SW_RST (1u << 31)
>> +
>> +/* I2C_FIFO_CTL Register bits */
>> +#define HSI2C_RXFIFO_EN (1u << 0)
>> +#define HSI2C_TXFIFO_EN (1u << 1)
>> +#define HSI2C_TXFIFO_TRIGGER_LEVEL (0x20 << 16)
>> +#define HSI2C_RXFIFO_TRIGGER_LEVEL (0x20 << 4)
>> +
>> +/* I2C_TRAILING_CTL Register bits */
>> +#define HSI2C_TRAILING_COUNT (0xf)
>> +
>> +/* I2C_INT_EN Register bits */
>> +#define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0)
>> +#define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1)
>> +#define HSI2C_INT_TRAILING_EN (1u << 6)
>> +#define HSI2C_INT_I2C_EN (1u << 9)
>> +
>> +/* I2C_FIFO_STAT Register bits */
>> +#define HSI2C_RX_FIFO_EMPTY (1u << 24)
>> +#define HSI2C_RX_FIFO_FULL (1u << 23)
>> +#define HSI2C_RX_FIFO_LEVEL_MASK (0x7 << 16)
>> +#define HSI2C_TX_FIFO_EMPTY (1u << 8)
>> +#define HSI2C_TX_FIFO_FULL (1u << 7)
>> +#define HSI2C_TX_FIFO_LEVEL_MASK (0x7 << 7)
>> +#define HSI2C_FIFO_EMPTY (0x1000100)
>> +
>> +/* I2C_CONF Register bits */
>> +#define HSI2C_AUTO_MODE (1u << 31)
>> +#define HSI2C_10BIT_ADDR_MODE (1u << 30)
>> +#define HSI2C_HS_MODE (1u << 29)
>> +
>> +/* I2C_AUTO_CONF Register bits */
>> +#define HSI2C_READ_WRITE (1u << 16)
>> +#define HSI2C_STOP_AFTER_TRANS (1u << 17)
>> +#define HSI2C_MASTER_RUN (1u << 31)
>> +
>> +/* I2C_TIMEOUT Register bits */
>> +#define HSI2C_TIMEOUT_EN (1u << 31)
>> +
>> +/* I2C_TRANS_STATUS register bits */
>> +#define HSI2C_MASTER_BUSY (1u << 17)
>> +#define HSI2C_SLAVE_BUSY (1u << 16)
>> +#define HSI2C_NO_DEV (1u << 3)
>> +#define HSI2C_NO_DEV_ACK (1u << 2)
>> +#define HSI2C_TRANS_ABORT (1u << 1)
>> +#define HSI2C_TRANS_DONE (1u << 0)
>> +
>> +/**
>> + * Although exynos5 supports max HS-IIC speed of 3.4Mhz,
>> + * but currently we are facing booting issues beyond 1Mhz
>> + * So limiting HS-IIC bus speed to 1Mhz
>> +*/
>> +#define HSI2C_HS_TX_CLOCK 1000000
>> +#define HSI2C_FS_TX_CLOCK 400000
>> +
>> +#define HSI2C_FAST_SPD 0
>> +#define HSI2C_HIGH_SPD 1
>> +
>> +#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
>> +
>> +/* timeout for pm runtime autosuspend */
>> +#define EXYNOS5_I2C_PM_TIMEOUT 1000 /* ms */
>> +
>> +struct exynos5_i2c {
>> + struct i2c_adapter adap;
>> + unsigned int suspended:1;
>> +
>> + struct i2c_msg *msg;
>> + unsigned int msg_idx;
>> + struct completion msg_complete;
>> + unsigned int msg_ptr;
>> +
>> + unsigned int irq;
>> +
>> + void __iomem *regs;
>> + struct clk *clk;
>> + struct device *dev;
>> + int gpios[2];
>> +
>> + int bus_num;
>> + int speed_mode;
>> + struct dentry *debugfs_root;
>> +};
>> +
>> +static const struct of_device_id exynos5_i2c_match[] = {
>> + { .compatible = "samsung,exynos5-hsi2c" },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
>> +
>> +static void exynos5_i2c_stop(struct exynos5_i2c *i2c, int err)
>> +{
>> + dev_vdbg(i2c->dev, "STOP\n");
>> +
>> + i2c->msg_idx++;
>> + if (err)
>> + i2c->msg_idx = err;
>> +
>> + /* Disable interrrupts */
>> + writel(0, i2c->regs + HSI2C_INT_ENABLE);
>> + complete(&i2c->msg_complete);
>> +}
>> +
>> +static void exynos5_i2c_en_timeout(struct exynos5_i2c *i2c)
>> +{
>> + unsigned long i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT);
>> +
>> + /* Clear to enable Timeout */
>> + i2c_timeout &= ~HSI2C_TIMEOUT_EN;
>> + writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT);
>> +}
>> +
>> +static void exynos5_i2c_master_run(struct exynos5_i2c *i2c)
>> +{
>> + /* Start data transfer in Master mode */
>> + u32 i2c_auto_conf = readl(i2c->regs + HSI2C_AUTO_CONF);
>> + i2c_auto_conf |= HSI2C_MASTER_RUN;
>> + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
>> +}
>> +
>> +/**
>> + * exynos5_i2c_set_bus: get the i2c bus for a master transaction
>> +*/
>> +static int exynos5_i2c_set_master(struct exynos5_i2c *i2c)
>> +{
>> + unsigned long t_status;
>> + int timeout = 400;
>> +
>> + while (timeout-- > 0) {
>> + t_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
>> +
>> + if (!(t_status & HSI2C_MASTER_BUSY))
>> + return 0;
>> +
>> + msleep(20);
>> + }
>> +
>> + return -ETIMEDOUT;
>> +}
>> +
>> +/**
>> + * exynos5_i2c_irq: top level IRQ servicing routine
>> +*/
>> +static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
>> +{
>> + struct exynos5_i2c *i2c = dev_id;
>> + unsigned long t_stat;
>> + unsigned char byte;
>> +
>> + t_stat = readl(i2c->regs + HSI2C_TRANS_STATUS);
>> +
>> + if (t_stat & HSI2C_TRANS_ABORT) {
>> + /* deal with arbitration loss */
>> + dev_err(i2c->dev, "deal with arbitration loss\n");
>> + goto out;
>> + }
>> + if (i2c->msg->flags & I2C_M_RD) {
>> + if (t_stat & HSI2C_TRANS_DONE) {
>> + dev_dbg(i2c->dev, "Device found.");
>> + while ((readl(i2c->regs + HSI2C_FIFO_STATUS) &
>> + HSI2C_RX_FIFO_EMPTY) == 0) {
>> + byte = readl(i2c->regs + HSI2C_RX_DATA);
>> + dev_dbg(i2c->dev, "read rx_data = %x", byte);
>> + i2c->msg->buf[i2c->msg_ptr++] = byte;
>> + }
>> +
>> + if (i2c->msg_ptr >= i2c->msg->len)
>> + exynos5_i2c_stop(i2c, 0);
>> +
>> + } else if (t_stat & HSI2C_NO_DEV) {
>> + dev_dbg(i2c->dev, "No device found.");
>> + exynos5_i2c_stop(i2c, -ENXIO);
>> + } else if (t_stat & HSI2C_NO_DEV_ACK &&
>> + !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
>> + dev_dbg(i2c->dev, "No device Ack.");
>> + exynos5_i2c_stop(i2c, -ENXIO);
>> + }
>> + } else {
>> + byte = i2c->msg->buf[i2c->msg_ptr++];
>> + dev_dbg(i2c->dev, "write tx_data = %x ", byte);
>> + writel(byte, i2c->regs + HSI2C_TX_DATA);
>> +
>> + if (i2c->msg_ptr >= i2c->msg->len)
>> + exynos5_i2c_stop(i2c, 0);
>> + }
>> +
>> + out:
>> + /* Set those bits to clear them */
>> + writel(readl(i2c->regs + HSI2C_INT_STATUS),
>> + i2c->regs + HSI2C_INT_STATUS);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static void exynos5_i2c_message_start(struct exynos5_i2c *i2c,
>> + struct i2c_msg *msgs)
>> +{
>> + unsigned long usi_ctl = HSI2C_FUNC_MODE_I2C | HSI2C_MASTER;
>> + unsigned long i2c_auto_conf;
>> + unsigned long i2c_addr = ((msgs->addr & 0x7f) << 10);
>> + unsigned long usi_int_en = 0;
>> +
>> + exynos5_i2c_en_timeout(i2c);
>> +
>> + if (msgs->flags & I2C_M_RD) {
>> + usi_ctl &= ~HSI2C_TXCHON;
>> + usi_ctl |= HSI2C_RXCHON;
>> +
>> + i2c_auto_conf |= HSI2C_READ_WRITE;
>> +
>> + usi_int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
>> + HSI2C_INT_TRAILING_EN);
>> + } else {
>> + usi_ctl &= ~HSI2C_RXCHON;
>> + usi_ctl |= HSI2C_TXCHON;
>> +
>> + i2c_auto_conf &= ~HSI2C_READ_WRITE;
>> +
>> + usi_int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
>> + }
>> +
>> + writel(i2c_addr, i2c->regs + HSI2C_ADDR);
>> + writel(usi_ctl, i2c->regs + HSI2C_CTL);
>> +
>> + i2c_auto_conf |= i2c->msg->len;
>> + i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS;
>> + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
>> +
>> + exynos5_i2c_master_run(i2c);
>> +
>> + /* Enable appropriate interrupts */
>> + writel(usi_int_en, i2c->regs + HSI2C_INT_ENABLE);
>> +}
>> +
>> +static int exynos5_i2c_doxfer(struct exynos5_i2c *i2c, struct i2c_msg *msgs)
>> +{
>> + unsigned long timeout;
>> + int ret;
>> +
>> + if (i2c->suspended) {
>> + dev_err(i2c->dev, "HS-I2C is not initialzed.\n");
>> + return -EIO;
>> + }
>> +
>> + if (exynos5_i2c_set_master(i2c)) {
>> + dev_err(i2c->dev, "cannot get bus, Master busy.\n");
>> + return -EAGAIN;
>> + }
>> +
>> + i2c->msg = msgs;
>> + i2c->msg_ptr = 0;
>> + i2c->msg_idx = 0;
>> +
>> + INIT_COMPLETION(i2c->msg_complete);
>> +
>> + exynos5_i2c_message_start(i2c, msgs);
>> +
>> + timeout = wait_for_completion_timeout(&i2c->msg_complete,
>> + EXYNOS5_I2C_TIMEOUT);
>> +
>> + ret = i2c->msg_idx;
>> +
>> + if (timeout == 0)
>> + dev_dbg(i2c->dev, "timeout\n");
>> + else if ((ret != msgs->len) && (ret < 0))
>> + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", i2c->msg_idx);
>> +
>> + return ret;
>> +}
>> +
>> +static int exynos5_i2c_xfer(struct i2c_adapter *adap,
>> + struct i2c_msg *msgs, int num)
>> +{
>> + struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data;
>> + int retry, i;
>> + int ret;
>> +
>> + ret = pm_runtime_get_sync(i2c->dev);
>> + if (IS_ERR_VALUE(ret))
>> + goto out;
>> +
>> + clk_prepare_enable(i2c->clk);
>> +
>> + for (retry = 0; retry < adap->retries; retry++) {
>> + for (i = 0; i < num; i++) {
>> + ret = exynos5_i2c_doxfer(i2c, msgs);
>> + msgs++;
>> +
>> + if (ret == -EAGAIN)
>> + break;
>> + }
>> + if (i == num) {
>> + clk_disable_unprepare(i2c->clk);
>> +
>> + if (i2c->msg_idx == -ENXIO)
>> + ret = i2c->msg_idx;
>> + else
>> + ret = num;
>> + goto out;
>> + }
>> +
>> + dev_dbg(i2c->dev, "retrying transfer (%d)\n", retry);
>> +
>> + udelay(100);
>> + }
>> +
>> + ret = -EREMOTEIO;
>> + clk_disable_unprepare(i2c->clk);
>> + out:
>> + pm_runtime_mark_last_busy(i2c->dev);
>> + pm_runtime_put_autosuspend(i2c->dev);
>> + return ret;
>> +}
>> +
>> +static u32 exynos5_i2c_func(struct i2c_adapter *adap)
>> +{
>> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
>> +}
>> +
>> +static const struct i2c_algorithm exynos5_i2c_algorithm = {
>> + .master_xfer = exynos5_i2c_xfer,
>> + .functionality = exynos5_i2c_func,
>> +};
>> +
>> +static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int speed_mode)
>> +{
>> + unsigned long i2c_timing_s1;
>> + unsigned long i2c_timing_s2;
>> + unsigned long i2c_timing_s3;
>> + unsigned long i2c_timing_sla;
>> + unsigned int op_clk;
>> + unsigned int clkin = clk_get_rate(i2c->clk);
>> + unsigned int n_clkdiv;
>> + unsigned int t_start_su, t_start_hd;
>> + unsigned int t_stop_su;
>> + unsigned int t_data_su, t_data_hd;
>> + unsigned int t_scl_l, t_scl_h;
>> + unsigned int t_sr_release;
>> + unsigned int t_ftl_cycle;
>> + unsigned int i = 0, utemp0 = 0, utemp1 = 0, utemp2 = 0;
>> +
>> + if (speed_mode == HSI2C_HIGH_SPD)
>> + op_clk = HSI2C_HS_TX_CLOCK;
>> + else
>> + op_clk = HSI2C_FS_TX_CLOCK;
>> +
>> + /* FPCLK / FI2C =
>> + * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
>> + * uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
>> + * uTemp1 = (TSCLK_L + TSCLK_H + 2)
>> + * uTemp2 = TSCLK_L + TSCLK_H
>> + */
>> + t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
>> + utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle;
>> +
>> + /* CLK_DIV max is 256 */
>> + for (i = 0; i < 256; i++) {
>> + utemp1 = utemp0 / (i + 1);
>> + /* SCLK_L/H max is 255
>> + * so sclk_l + sclk_h has max value of 510
>> + */
>> + if (utemp1 < 511) {
>> + utemp2 = utemp1 - 2;
>> + break;
>> + }
>> + }
>> +
>> + n_clkdiv = i;
>> + t_scl_l = utemp2 / 2;
>> + t_scl_h = utemp2 / 2;
>> + t_start_su = t_scl_l;
>> + t_start_hd = t_scl_l;
>> + t_stop_su = t_scl_l;
>> + t_data_su = t_scl_l / 2;
>> + t_data_hd = t_scl_l / 2;
>> + t_sr_release = utemp2;
>> +
>> + i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8;
>> + i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0;
>> + i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0;
>> + i2c_timing_sla = t_data_hd << 0;
>> +
>> + dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n",
>> + t_start_su, t_start_hd, t_stop_su);
>> + dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n",
>> + t_data_su, t_scl_l, t_scl_h);
>> + dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n",
>> + n_clkdiv, t_sr_release);
>> + dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
>> +
>> + if (speed_mode == HSI2C_HIGH_SPD) {
>> + writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1);
>> + writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2);
>> + writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3);
>> + } else {
>> + writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1);
>> + writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2);
>> + writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3);
>> + }
>> + writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA);
>> +
>> + return 0;
>> +}
>> +
>> +/**
>> + * Parse a list of GPIOs from a node property and request each one
>> + *
>> + * @param i2c i2c driver data
>> + * @return 0 on success, -EINVAL on error, in which case no GPIOs requested
>> +*/
>> +static int exynos5_i2c_parse_dt_gpio(struct exynos5_i2c *i2c)
>> +{
>> + int idx, gpio, ret;
>> +
>> + for (idx = 0; idx < 2; idx++) {
>> + gpio = of_get_gpio(i2c->dev->of_node, idx);
>> + if (!gpio_is_valid(gpio)) {
>> + dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio);
>> + return -EINVAL;
>> + }
>> + i2c->gpios[idx] = gpio;
>> +
>> + ret = devm_gpio_request(i2c->dev, gpio, "i2c-bus");
>> + if (ret) {
>> + dev_err(i2c->dev, "gpio [%d] request failed\n", gpio);
>> + return -EINVAL;
>> + }
>> + }
>> + return 0;
>> +}
>> +
>> +static void exynos5_i2c_init(struct exynos5_i2c *i2c)
>> +{
>> + unsigned long usi_trailing_ctl = HSI2C_TRAILING_COUNT;
>> + unsigned long i2c_conf = HSI2C_AUTO_MODE;
>> + unsigned long usi_fifo_ctl;
>> +
>> + writel(usi_trailing_ctl, i2c->regs + HSI2C_TRAILIG_CTL);
>> +
>> + /* Set default trigger level for TXFIFO and RXFIFO */
>> + usi_fifo_ctl = HSI2C_TXFIFO_TRIGGER_LEVEL | HSI2C_RXFIFO_TRIGGER_LEVEL;
>> +
>> + /* Enable RXFIFO and TXFIFO */
>> + usi_fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN;
>> + writel(usi_fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
>> +
>> + if (i2c->speed_mode == HSI2C_HIGH_SPD) {
>> + exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD);
>> + /* Configure I2C controller in High speed mode */
>> + i2c_conf |= HSI2C_HS_MODE;
>> + writel(i2c_conf, i2c->regs + HSI2C_CONF);
>> + } else {
>> + /* Configure I2C controller in Fast speed mode */
>> + exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD);
>> + }
>> +}
>> +
>> +#define HSI2C_REG(regname) {.name = #regname, .offset = regname}
>> +static struct debugfs_reg32 exynos5_hsi2c_regs[] = {
>> + HSI2C_REG(HSI2C_CTL), HSI2C_REG(HSI2C_FIFO_CTL),
>> + HSI2C_REG(HSI2C_TRAILIG_CTL), HSI2C_REG(HSI2C_CLK_CTL),
>> + HSI2C_REG(HSI2C_CLK_SLOT), HSI2C_REG(HSI2C_INT_ENABLE),
>> + HSI2C_REG(HSI2C_INT_STATUS), HSI2C_REG(HSI2C_ERR_STATUS),
>> + HSI2C_REG(HSI2C_FIFO_STATUS), HSI2C_REG(HSI2C_TX_DATA),
>> + HSI2C_REG(HSI2C_RX_DATA), HSI2C_REG(HSI2C_CONF),
>> + HSI2C_REG(HSI2C_AUTO_CONF), HSI2C_REG(HSI2C_TIMEOUT),
>> + HSI2C_REG(HSI2C_MANUAL_CMD), HSI2C_REG(HSI2C_TRANS_STATUS),
>> + HSI2C_REG(HSI2C_TIMING_HS1), HSI2C_REG(HSI2C_TIMING_HS2),
>> + HSI2C_REG(HSI2C_TIMING_HS3), HSI2C_REG(HSI2C_TIMING_FS1),
>> + HSI2C_REG(HSI2C_TIMING_FS2), HSI2C_REG(HSI2C_TIMING_FS3),
>> + HSI2C_REG(HSI2C_TIMING_SLA), HSI2C_REG(HSI2C_ADDR),
>> +};
>> +
>> +static struct debugfs_regset32 exynos5_hsi2c_regset = {
>> + .regs = exynos5_hsi2c_regs,
>> + .nregs = ARRAY_SIZE(exynos5_hsi2c_regs),
>> +};
>> +
>> +static struct dentry *exynos5_hsi2c_reg_debugfs;
>> +
>> +static int exynos5_i2c_probe(struct platform_device *pdev)
>> +{
>> + struct device_node *np = pdev->dev.of_node;
>> + struct exynos5_i2c *i2c;
>> + int ret;
>> +
>> + if (!np) {
>> + dev_err(&pdev->dev, "no device node\n");
>> + return -ENOENT;
>> + }
>> +
>> + i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
>> + if (!i2c) {
>> + dev_err(&pdev->dev, "no memory for state\n");
>> + return -ENOMEM;
>> + }
>> +
>> + i2c->bus_num = -1;
>> + /* Mode of operation High/Fast Speed mode */
>> + of_property_read_u32(np, "samsung,hs-mode", &i2c->speed_mode);
>> +
>> + strlcpy(i2c->adap.name, "exynos5-hsi2c", sizeof(i2c->adap.name));
>> + i2c->adap.owner = THIS_MODULE;
>> + i2c->adap.algo = &exynos5_i2c_algorithm;
>> + i2c->adap.retries = 2;
>> + i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
>> +
>> + i2c->dev = &pdev->dev;
>> + i2c->clk = clk_get(&pdev->dev, "hsi2c");
>> + if (IS_ERR(i2c->clk)) {
>> + dev_err(&pdev->dev, "cannot get clock\n");
>> + ret = -ENOENT;
>> + goto err_noclk;
>> + }
>> +
>> + dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
>> +
>> + clk_prepare_enable(i2c->clk);
>> +
>> + i2c->regs = of_iomap(np, 0);
>> + if (!i2c->regs) {
>> + dev_err(&pdev->dev, "cannot map HS-I2C IO\n");
>> + ret = -ENXIO;
>> + goto err_clk;
>> + }
>> +
>> + /* inititalise the gpio */
>> + if (exynos5_i2c_parse_dt_gpio(i2c))
>> + return -EINVAL;
>> +
>> + i2c->irq = irq_of_parse_and_map(np, 0);
>> + if (i2c->irq) {
>> + ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
>> + 0, dev_name(&pdev->dev), i2c);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n",
>> + i2c->irq);
>> + goto err_iomap;
>> + }
>> + }
>> +
>> + /*
>> + * TODO: Use private lock to avoid race conditions as
>> + * mentioned in pm_runtime.txt
>> + */
>> + pm_runtime_enable(i2c->dev);
>> + pm_runtime_set_autosuspend_delay(i2c->dev, EXYNOS5_I2C_PM_TIMEOUT);
>> + pm_runtime_use_autosuspend(i2c->dev);
>> +
>> + ret = pm_runtime_get_sync(i2c->dev);
>> + if (IS_ERR_VALUE(ret))
>> + goto err_iomap;
>> +
>> + exynos5_i2c_init(i2c);
>> +
>> + i2c->adap.algo_data = i2c;
>> + i2c->adap.dev.parent = &pdev->dev;
>> + i2c->adap.nr = i2c->bus_num;
>> + i2c->adap.dev.of_node = pdev->dev.of_node;
>> +
>> + ret = i2c_add_numbered_adapter(&i2c->adap);
>> + if (ret < 0) {
>> + dev_err(&pdev->dev, "failed to add bus to i2c core\n");
>> + goto err_pm;
>> + }
>> +
>> + init_completion(&i2c->msg_complete);
>> + of_i2c_register_devices(&i2c->adap);
>> + platform_set_drvdata(pdev, i2c);
>> +
>> + dev_info(&pdev->dev, "%s: Exynos5 HS-I2C adapter\n",
>> + dev_name(&i2c->adap.dev));
>> +
>> + exynos5_hsi2c_reg_debugfs = debugfs_create_regset32("exynos5-hsi2c",
>> + S_IFREG | S_IRUGO,
>> + NULL, &exynos5_hsi2c_regset);
> I took the reference of this call from MFD driver, which is the only
> driver using this (i guess)
> usb/dwc3.c driver had a generic implementation. I wasn't sure of the
> implementation.
> if someone can help, i willing to do that.
>> + clk_disable_unprepare(i2c->clk);
>> + pm_runtime_mark_last_busy(i2c->dev);
>> + pm_runtime_put_autosuspend(i2c->dev);
>> + return 0;
>> +
>> + err_pm:
>> + pm_runtime_put(i2c->dev);
>> + pm_runtime_disable(&pdev->dev);
>> + err_iomap:
>> + iounmap(i2c->regs);
>> + err_clk:
>> + clk_disable_unprepare(i2c->clk);
>> + err_noclk:
>> + return ret;
>> +}
>> +
>> +static int exynos5_i2c_remove(struct platform_device *pdev)
>> +{
>> + struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
>> + int ret;
>> +
>> + ret = pm_runtime_get_sync(&pdev->dev);
>> + if (IS_ERR_VALUE(ret))
>> + return ret;
>> +
>> + clk_disable_unprepare(i2c->clk);
>> + pm_runtime_put(&pdev->dev);
>> + pm_runtime_disable(&pdev->dev);
>> +
>> + i2c_del_adapter(&i2c->adap);
>> +
>> + iounmap(i2c->regs);
>> + platform_set_drvdata(pdev, NULL);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +static int exynos5_i2c_suspend_noirq(struct device *dev)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> + struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
>> +
>> + i2c->suspended = 1;
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos5_i2c_resume_noirq(struct device *dev)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> + struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
>> +
>> + clk_prepare_enable(i2c->clk);
>> + exynos5_i2c_init(i2c);
>> + clk_disable_unprepare(i2c->clk);
>> + i2c->suspended = 0;
>> +
>> + return 0;
>> +}
>> +
>> +static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
>> + .suspend_noirq = exynos5_i2c_suspend_noirq,
>> + .resume_noirq = exynos5_i2c_resume_noirq,
>> +};
>> +
>> +#define EXYNOS5_DEV_PM_OPS (&exynos5_i2c_dev_pm_ops)
>> +#else
>> +#define EXYNOS5_DEV_PM_OPS NULL
>> +#endif
>> +
>> +static struct platform_driver exynos5_i2c_driver = {
>> + .probe = exynos5_i2c_probe,
>> + .remove = exynos5_i2c_remove,
>> + .driver = {
>> + .owner = THIS_MODULE,
>> + .name = "exynos5-hsi2c",
>> + .pm = EXYNOS5_DEV_PM_OPS,
>> + .of_match_table = exynos5_i2c_match,
>> + },
>> +};
>> +
>> +static int __init i2c_adap_exynos5_init(void)
>> +{
>> + return platform_driver_register(&exynos5_i2c_driver);
>> +}
>> +subsys_initcall(i2c_adap_exynos5_init);
>> +
>> +static void __exit i2c_adap_exynos5_exit(void)
>> +{
>> + platform_driver_unregister(&exynos5_i2c_driver);
>> +}
>> +module_exit(i2c_adap_exynos5_exit);
>> +
>> +MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver");
>> +MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@...sung.com>");
>> +MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@...sung.com>");
>> +MODULE_LICENSE("GPL");
>> --
>> 1.7.9.5
Any comments please. Thanks in advance
>>
>
>
>
> --
> Shine bright,
> (: Nav :)
--
Shine bright,
(: Nav :)
--
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