--- /dev/null
+/**
+ * i2c-exynos5.c - Samsung Exynos5 I2C Controller Driver
+ *
+ * Copyright (C) 2013 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/i2c.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/clk.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/spinlock.h>
+
+/*
+ * HSI2C controller from Samsung supports 2 modes of operation
+ * 1. Auto mode: Where in master automatically controls the whole transaction
+ * 2. Manual mode: Software controls the transaction by issuing commands
+ * START, READ, WRITE, STOP, RESTART in I2C_MANUAL_CMD register.
+ *
+ * Operation mode can be selected by setting AUTO_MODE bit in I2C_CONF register
+ *
+ * Special bits are available for both modes of operation to set commands
+ * and for checking transfer status
+ */
+
+/* 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_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4)
+#define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16)
+
+/* 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)
+
+/* I2C_INT_STAT Register bits */
+#define HSI2C_INT_TX_ALMOSTEMPTY (1u << 0)
+#define HSI2C_INT_RX_ALMOSTFULL (1u << 1)
+#define HSI2C_INT_TX_UNDERRUN (1u << 2)
+#define HSI2C_INT_TX_OVERRUN (1u << 3)
+#define HSI2C_INT_RX_UNDERRUN (1u << 4)
+#define HSI2C_INT_RX_OVERRUN (1u << 5)
+#define HSI2C_INT_TRAILING (1u << 6)
+#define HSI2C_INT_I2C (1u << 9)
+
+#define HSI2C_INT_TRANS_DONE (1u << 7)
+#define HSI2C_INT_TRANS_ABORT (1u << 8)
+#define HSI2C_INT_NO_DEV_ACK (1u << 9)
+#define HSI2C_INT_NO_DEV (1u << 10)
+#define HSI2C_INT_TIMEOUT (1u << 11)
+#define HSI2C_INT_I2C_TRANS (HSI2C_INT_TRANS_DONE | \
+ HSI2C_INT_TRANS_ABORT | \
+ HSI2C_INT_NO_DEV_ACK | \
+ HSI2C_INT_NO_DEV | \
+ HSI2C_INT_TIMEOUT)
+
+/* I2C_FIFO_STAT Register bits */
+#define HSI2C_RX_FIFO_EMPTY (1u << 24)
+#define HSI2C_RX_FIFO_FULL (1u << 23)
+#define HSI2C_RX_FIFO_LVL(x) ((x >> 16) & 0x7f)
+#define HSI2C_TX_FIFO_EMPTY (1u << 8)
+#define HSI2C_TX_FIFO_FULL (1u << 7)
+#define HSI2C_TX_FIFO_LVL(x) ((x >> 0) & 0x7f)
+
+/* 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)
+#define HSI2C_TIMEOUT_MASK 0xff
+
+/* I2C_TRANS_STATUS register bits */
+#define HSI2C_MASTER_BUSY (1u << 17)
+#define HSI2C_SLAVE_BUSY (1u << 16)
+#define HSI2C_TIMEOUT_AUTO (1u << 4)
+#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)
+
+/* I2C_ADDR register bits */
+#define HSI2C_SLV_ADDR_SLV(x) ((x & 0x3ff) << 0)
+#define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10)
+#define HSI2C_MASTER_ID(x) ((x & 0xff) << 24)
+#define MASTER_ID(x) ((x & 0x7) + 0x08)
+
+/*
+ * Controller operating frequency, timing values for operation
+ * are calculated against this frequency
+ */
+#define HSI2C_HS_TX_CLOCK 1000000
+#define HSI2C_FS_TX_CLOCK 100000
+#define HSI2C_HIGH_SPD 1
+#define HSI2C_FAST_SPD 0
+
+#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+#define HSI2C_EXYNOS7 BIT(0)
+
+struct exynos5_i2c {
+ struct i2c_adapter adap;
+ unsigned int suspended:1;
+
+ struct i2c_msg *msg;
+ struct completion msg_complete;
+ unsigned int msg_ptr;
+
+ unsigned int irq;
+
+ void __iomem *regs;
+ struct clk *clk;
+ struct device *dev;
+ int state;
+
+ spinlock_t lock; /* IRQ synchronization */
+
+ /*
+ * Since the TRANS_DONE bit is cleared on read, and we may read it
+ * either during an IRQ or after a transaction, keep track of its
+ * state here.
+ */
+ int trans_done;
+
+ /* Controller operating frequency */
+ unsigned int fs_clock;
+ unsigned int hs_clock;
+
+ /*
+ * HSI2C Controller can operate in
+ * 1. High speed upto 3.4Mbps
+ * 2. Fast speed upto 1Mbps
+ */
+ int speed_mode;
+
+ /* Version of HS-I2C Hardware */
+ struct exynos_hsi2c_variant *variant;
+};
+
+/**
+ * struct exynos_hsi2c_variant - platform specific HSI2C driver data
+ * @fifo_depth: the fifo depth supported by the HSI2C module
+ *
+ * Specifies platform specific configuration of HSI2C module.
+ * Note: A structure for driver specific platform data is used for future
+ * expansion of its usage.
+ */
+struct exynos_hsi2c_variant {
+ unsigned int fifo_depth;
+ unsigned int hw;
+};
+
+static const struct exynos_hsi2c_variant exynos5250_hsi2c_data = {
+ .fifo_depth = 64,
+};
+
+static const struct exynos_hsi2c_variant exynos5260_hsi2c_data = {
+ .fifo_depth = 16,
+};
+
+static const struct exynos_hsi2c_variant exynos7_hsi2c_data = {
+ .fifo_depth = 16,
+ .hw = HSI2C_EXYNOS7,
+};
+
+static const struct of_device_id exynos5_i2c_match[] = {
+ {
+ .compatible = "samsung,exynos5-hsi2c",
+ .data = &exynos5250_hsi2c_data
+ }, {
+ .compatible = "samsung,exynos5250-hsi2c",
+ .data = &exynos5250_hsi2c_data
+ }, {
+ .compatible = "samsung,exynos5260-hsi2c",
+ .data = &exynos5260_hsi2c_data
+ }, {
+ .compatible = "samsung,exynos7-hsi2c",
+ .data = &exynos7_hsi2c_data
+ }, {},
+};
+MODULE_DEVICE_TABLE(of, exynos5_i2c_match);
+
+static inline struct exynos_hsi2c_variant *exynos5_i2c_get_variant
+ (struct platform_device *pdev)
+{
+ const struct of_device_id *match;
+
+ match = of_match_node(exynos5_i2c_match, pdev->dev.of_node);
+ return (struct exynos_hsi2c_variant *)match->data;
+}
+
+static void exynos5_i2c_clr_pend_irq(struct exynos5_i2c *i2c)
+{
+ writel(readl(i2c->regs + HSI2C_INT_STATUS),
+ i2c->regs + HSI2C_INT_STATUS);
+}
+
+/*
+ * exynos5_i2c_set_timing: updates the registers with appropriate
+ * timing values calculated
+ *
+ * Returns 0 on success, -EINVAL if the cycle length cannot
+ * be calculated.
+ */
+static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int mode)
+{
+ u32 i2c_timing_s1;
+ u32 i2c_timing_s2;
+ u32 i2c_timing_s3;
+ u32 i2c_timing_sla;
+ 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 clkin = clk_get_rate(i2c->clk);
+ unsigned int div, utemp0 = 0, utemp1 = 0, clk_cycle;
+ unsigned int op_clk = (mode == HSI2C_HIGH_SPD) ?
+ i2c->hs_clock : i2c->fs_clock;
+
+ /*
+ * In case of HSI2C controller in Exynos5 series
+ * FPCLK / FI2C =
+ * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE
+ *
+ * In case of HSI2C controllers in Exynos7 series
+ * FPCLK / FI2C =
+ * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + FLT_CYCLE
+ *
+ * utemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2)
+ * utemp1 = (TSCLK_L + TSCLK_H + 2)
+ */
+ t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
+ utemp0 = (clkin / op_clk) - 8;
+
+ if (i2c->variant->hw == HSI2C_EXYNOS7)
+ utemp0 -= t_ftl_cycle;
+ else
+ utemp0 -= 2 * t_ftl_cycle;
+
+ /* CLK_DIV max is 256 */
+ for (div = 0; div < 256; div++) {
+ utemp1 = utemp0 / (div + 1);
+
+ /*
+ * SCL_L and SCL_H each has max value of 255
+ * Hence, For the clk_cycle to the have right value
+ * utemp1 has to be less then 512 and more than 4.
+ */
+ if ((utemp1 < 512) && (utemp1 > 4)) {
+ clk_cycle = utemp1 - 2;
+ break;
+ } else if (div == 255) {
+ dev_warn(i2c->dev, "Failed to calculate divisor");
+ return -EINVAL;
+ }
+ }
+
+ t_scl_l = clk_cycle / 2;
+ t_scl_h = clk_cycle / 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 = clk_cycle;
+
+ 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 = div << 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",
+ div, t_sr_release);
+ dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd);
+
+ if (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;
+}
+
+static int exynos5_hsi2c_clock_setup(struct exynos5_i2c *i2c)
+{
+ /*
+ * Configure the Fast speed timing values
+ * Even the High Speed mode initially starts with Fast mode
+ */
+ if (exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD)) {
+ dev_err(i2c->dev, "HSI2C FS Clock set up failed\n");
+ return -EINVAL;
+ }
+
+ /* configure the High speed timing values */
+ if (i2c->speed_mode == HSI2C_HIGH_SPD) {
+ if (exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD)) {
+ dev_err(i2c->dev, "HSI2C HS Clock set up failed\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * exynos5_i2c_init: configures the controller for I2C functionality
+ * Programs I2C controller for Master mode operation
+ */
+static void exynos5_i2c_init(struct exynos5_i2c *i2c)
+{
+ u32 i2c_conf = readl(i2c->regs + HSI2C_CONF);
+ u32 i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT);
+
+ /* Clear to disable Timeout */
+ i2c_timeout &= ~HSI2C_TIMEOUT_EN;
+ writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT);
+
+ writel((HSI2C_FUNC_MODE_I2C | HSI2C_MASTER),
+ i2c->regs + HSI2C_CTL);
+ writel(HSI2C_TRAILING_COUNT, i2c->regs + HSI2C_TRAILIG_CTL);
+
+ if (i2c->speed_mode == HSI2C_HIGH_SPD) {
+ writel(HSI2C_MASTER_ID(MASTER_ID(i2c->adap.nr)),
+ i2c->regs + HSI2C_ADDR);
+ i2c_conf |= HSI2C_HS_MODE;
+ }
+
+ writel(i2c_conf | HSI2C_AUTO_MODE, i2c->regs + HSI2C_CONF);
+}
+
+static void exynos5_i2c_reset(struct exynos5_i2c *i2c)
+{
+ u32 i2c_ctl;
+
+ /* Set and clear the bit for reset */
+ i2c_ctl = readl(i2c->regs + HSI2C_CTL);
+ i2c_ctl |= HSI2C_SW_RST;
+ writel(i2c_ctl, i2c->regs + HSI2C_CTL);
+
+ i2c_ctl = readl(i2c->regs + HSI2C_CTL);
+ i2c_ctl &= ~HSI2C_SW_RST;
+ writel(i2c_ctl, i2c->regs + HSI2C_CTL);
+
+ /* We don't expect calculations to fail during the run */
+ exynos5_hsi2c_clock_setup(i2c);
+ /* Initialize the configure registers */
+ exynos5_i2c_init(i2c);
+}
+
+/*
+ * exynos5_i2c_irq: top level IRQ servicing routine
+ *
+ * INT_STATUS registers gives the interrupt details. Further,
+ * FIFO_STATUS or TRANS_STATUS registers are to be check for detailed
+ * state of the bus.
+ */
+static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
+{
+ struct exynos5_i2c *i2c = dev_id;
+ u32 fifo_level, int_status, fifo_status, trans_status;
+ unsigned char byte;
+ int len = 0;
+
+ i2c->state = -EINVAL;
+
+ spin_lock(&i2c->lock);
+
+ int_status = readl(i2c->regs + HSI2C_INT_STATUS);
+ writel(int_status, i2c->regs + HSI2C_INT_STATUS);
+
+ /* handle interrupt related to the transfer status */
+ if (i2c->variant->hw == HSI2C_EXYNOS7) {
+ if (int_status & HSI2C_INT_TRANS_DONE) {
+ i2c->trans_done = 1;
+ i2c->state = 0;
+ } else if (int_status & HSI2C_INT_TRANS_ABORT) {
+ dev_dbg(i2c->dev, "Deal with arbitration lose\n");
+ i2c->state = -EAGAIN;
+ goto stop;
+ } else if (int_status & HSI2C_INT_NO_DEV_ACK) {
+ dev_dbg(i2c->dev, "No ACK from device\n");
+ i2c->state = -ENXIO;
+ goto stop;
+ } else if (int_status & HSI2C_INT_NO_DEV) {
+ dev_dbg(i2c->dev, "No device\n");
+ i2c->state = -ENXIO;
+ goto stop;
+ } else if (int_status & HSI2C_INT_TIMEOUT) {
+ dev_dbg(i2c->dev, "Accessing device timed out\n");
+ i2c->state = -ETIMEDOUT;
+ goto stop;
+ }
+ } else if (int_status & HSI2C_INT_I2C) {
+ trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+ if (trans_status & HSI2C_NO_DEV_ACK) {
+ dev_dbg(i2c->dev, "No ACK from device\n");
+ i2c->state = -ENXIO;
+ goto stop;
+ } else if (trans_status & HSI2C_NO_DEV) {
+ dev_dbg(i2c->dev, "No device\n");
+ i2c->state = -ENXIO;
+ goto stop;
+ } else if (trans_status & HSI2C_TRANS_ABORT) {
+ dev_dbg(i2c->dev, "Deal with arbitration lose\n");
+ i2c->state = -EAGAIN;
+ goto stop;
+ } else if (trans_status & HSI2C_TIMEOUT_AUTO) {
+ dev_dbg(i2c->dev, "Accessing device timed out\n");
+ i2c->state = -ETIMEDOUT;
+ goto stop;
+ } else if (trans_status & HSI2C_TRANS_DONE) {
+ i2c->trans_done = 1;
+ i2c->state = 0;
+ }
+ }
+
+ if ((i2c->msg->flags & I2C_M_RD) && (int_status &
+ (HSI2C_INT_TRAILING | HSI2C_INT_RX_ALMOSTFULL))) {
+ fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
+ fifo_level = HSI2C_RX_FIFO_LVL(fifo_status);
+ len = min(fifo_level, i2c->msg->len - i2c->msg_ptr);
+
+ while (len > 0) {
+ byte = (unsigned char)
+ readl(i2c->regs + HSI2C_RX_DATA);
+ i2c->msg->buf[i2c->msg_ptr++] = byte;
+ len--;
+ }
+ i2c->state = 0;
+ } else if (int_status & HSI2C_INT_TX_ALMOSTEMPTY) {
+ fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
+ fifo_level = HSI2C_TX_FIFO_LVL(fifo_status);
+
+ len = i2c->variant->fifo_depth - fifo_level;
+ if (len > (i2c->msg->len - i2c->msg_ptr))
+ len = i2c->msg->len - i2c->msg_ptr;
+
+ while (len > 0) {
+ byte = i2c->msg->buf[i2c->msg_ptr++];
+ writel(byte, i2c->regs + HSI2C_TX_DATA);
+ len--;
+ }
+ i2c->state = 0;
+ }
+
+ stop:
+ if ((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) ||
+ (i2c->state < 0)) {
+ writel(0, i2c->regs + HSI2C_INT_ENABLE);
+ exynos5_i2c_clr_pend_irq(i2c);
+ complete(&i2c->msg_complete);
+ }
+
+ spin_unlock(&i2c->lock);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * exynos5_i2c_wait_bus_idle
+ *
+ * Wait for the bus to go idle, indicated by the MASTER_BUSY bit being
+ * cleared.
+ *
+ * Returns -EBUSY if the bus cannot be bought to idle
+ */
+static int exynos5_i2c_wait_bus_idle(struct exynos5_i2c *i2c)
+{
+ unsigned long stop_time;
+ u32 trans_status;
+
+ /* wait for 100 milli seconds for the bus to be idle */
+ stop_time = jiffies + msecs_to_jiffies(100) + 1;
+ do {
+ trans_status = readl(i2c->regs + HSI2C_TRANS_STATUS);
+ if (!(trans_status & HSI2C_MASTER_BUSY))
+ return 0;
+
+ usleep_range(50, 200);
+ } while (time_before(jiffies, stop_time));
+
+ return -EBUSY;
+}
+
+/*
+ * exynos5_i2c_message_start: Configures the bus and starts the xfer
+ * i2c: struct exynos5_i2c pointer for the current bus
+ * stop: Enables stop after transfer if set. Set for last transfer of
+ * in the list of messages.
+ *
+ * Configures the bus for read/write function
+ * Sets chip address to talk to, message length to be sent.
+ * Enables appropriate interrupts and sends start xfer command.
+ */
+static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
+{
+ u32 i2c_ctl;
+ u32 int_en = 0;
+ u32 i2c_auto_conf = 0;
+ u32 fifo_ctl;
+ unsigned long flags;
+ unsigned short trig_lvl;
+
+ if (i2c->variant->hw == HSI2C_EXYNOS7)
+ int_en |= HSI2C_INT_I2C_TRANS;
+ else
+ int_en |= HSI2C_INT_I2C;
+
+ i2c_ctl = readl(i2c->regs + HSI2C_CTL);
+ i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
+ fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN;
+
+ if (i2c->msg->flags & I2C_M_RD) {
+ i2c_ctl |= HSI2C_RXCHON;
+
+ i2c_auto_conf |= HSI2C_READ_WRITE;
+
+ trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
+ (i2c->variant->fifo_depth * 3 / 4) : i2c->msg->len;
+ fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl);
+
+ int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
+ HSI2C_INT_TRAILING_EN);
+ } else {
+ i2c_ctl |= HSI2C_TXCHON;
+
+ trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
+ (i2c->variant->fifo_depth * 1 / 4) : i2c->msg->len;
+ fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl);
+
+ int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
+ }
+
+ writel(HSI2C_SLV_ADDR_MAS(i2c->msg->addr), i2c->regs + HSI2C_ADDR);
+
+ writel(fifo_ctl, i2c->regs + HSI2C_FIFO_CTL);
+ writel(i2c_ctl, i2c->regs + HSI2C_CTL);
+
+ /*
+ * Enable interrupts before starting the transfer so that we don't
+ * miss any INT_I2C interrupts.
+ */
+ spin_lock_irqsave(&i2c->lock, flags);
+ writel(int_en, i2c->regs + HSI2C_INT_ENABLE);
+
+ if (stop == 1)
+ i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS;
+ i2c_auto_conf |= i2c->msg->len;
+ i2c_auto_conf |= HSI2C_MASTER_RUN;
+ writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF);
+ spin_unlock_irqrestore(&i2c->lock, flags);
+}
+
+static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
+ struct i2c_msg *msgs, int stop)
+{
+ unsigned long timeout;
+ int ret;
+
+ i2c->msg = msgs;
+ i2c->msg_ptr = 0;
+ i2c->trans_done = 0;
+
+ reinit_completion(&i2c->msg_complete);
+
+ exynos5_i2c_message_start(i2c, stop);
+
+ timeout = wait_for_completion_timeout(&i2c->msg_complete,
+ EXYNOS5_I2C_TIMEOUT);
+ if (timeout == 0)
+ ret = -ETIMEDOUT;
+ else
+ ret = i2c->state;
+
+ /*
+ * If this is the last message to be transfered (stop == 1)
+ * Then check if the bus can be brought back to idle.
+ */
+ if (ret == 0 && stop)
+ ret = exynos5_i2c_wait_bus_idle(i2c);
+
+ if (ret < 0) {
+ exynos5_i2c_reset(i2c);
+ if (ret == -ETIMEDOUT)
+ dev_warn(i2c->dev, "%s timeout\n",
+ (msgs->flags & I2C_M_RD) ? "rx" : "tx");
+ }
+
+ /* Return the state as in interrupt routine */
+ return ret;
+}
+
+static int exynos5_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct exynos5_i2c *i2c = adap->algo_data;
+ int i = 0, ret = 0, stop = 0;
+
+ if (i2c->suspended) {
+ dev_err(i2c->dev, "HS-I2C is not initialized.\n");
+ return -EIO;
+ }
+
+ clk_prepare_enable(i2c->clk);
+
+ for (i = 0; i < num; i++, msgs++) {
+ stop = (i == num - 1);
+
+ ret = exynos5_i2c_xfer_msg(i2c, msgs, stop);
+
+ if (ret < 0)
+ goto out;
+ }
+
+ if (i == num) {
+ ret = num;
+ } else {
+ /* Only one message, cannot access the device */
+ if (i == 1)
+ ret = -EREMOTEIO;
+ else
+ ret = i;
+
+ dev_warn(i2c->dev, "xfer message failed\n");
+ }
+
+ out:
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+}
+
+static u32 exynos5_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm exynos5_i2c_algorithm = {
+ .master_xfer = exynos5_i2c_xfer,
+ .functionality = exynos5_i2c_func,
+};
+
+static int exynos5_i2c_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct exynos5_i2c *i2c;
+ struct resource *mem;
+ unsigned int op_clock;
+ int ret;
+
+ i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
+ i2c->speed_mode = HSI2C_FAST_SPD;
+ i2c->fs_clock = HSI2C_FS_TX_CLOCK;
+ } else {
+ if (op_clock >= HSI2C_HS_TX_CLOCK) {
+ i2c->speed_mode = HSI2C_HIGH_SPD;
+ i2c->fs_clock = HSI2C_FS_TX_CLOCK;
+ i2c->hs_clock = op_clock;
+ } else {
+ i2c->speed_mode = HSI2C_FAST_SPD;
+ i2c->fs_clock = op_clock;
+ }
+ }
+
+ strlcpy(i2c->adap.name, "exynos5-i2c", sizeof(i2c->adap.name));
+ i2c->adap.owner = THIS_MODULE;
+ i2c->adap.algo = &exynos5_i2c_algorithm;
+ i2c->adap.retries = 3;
+
+ i2c->dev = &pdev->dev;
+ i2c->clk = devm_clk_get(&pdev->dev, "hsi2c");
+ if (IS_ERR(i2c->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ return -ENOENT;
+ }
+
+ clk_prepare_enable(i2c->clk);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(i2c->regs)) {
+ ret = PTR_ERR(i2c->regs);
+ goto err_clk;
+ }
+
+ i2c->adap.dev.of_node = np;
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = &pdev->dev;
+
+ /* Clear pending interrupts from u-boot or misc causes */
+ exynos5_i2c_clr_pend_irq(i2c);
+
+ spin_lock_init(&i2c->lock);
+ init_completion(&i2c->msg_complete);
+
+ i2c->irq = ret = platform_get_irq(pdev, 0);
+ if (ret <= 0) {
+ dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
+ ret = -EINVAL;
+ goto err_clk;
+ }
+
+ ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq,
+ IRQF_NO_SUSPEND | IRQF_ONESHOT,
+ dev_name(&pdev->dev), i2c);
+
+ if (ret != 0) {
+ dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq);
+ goto err_clk;
+ }
+
+ /* Need to check the variant before setting up. */
+ i2c->variant = exynos5_i2c_get_variant(pdev);
+
+ ret = exynos5_hsi2c_clock_setup(i2c);
+ if (ret)
+ goto err_clk;
+
+ exynos5_i2c_reset(i2c);
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ goto err_clk;
+ }
+
+ platform_set_drvdata(pdev, i2c);
+
+ err_clk:
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+}
+
+static int exynos5_i2c_remove(struct platform_device *pdev)
+{
+ struct exynos5_i2c *i2c = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&i2c->adap);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+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);
+ int ret = 0;
+
+ clk_prepare_enable(i2c->clk);
+
+ ret = exynos5_hsi2c_clock_setup(i2c);
+ if (ret) {
+ clk_disable_unprepare(i2c->clk);
+ return ret;
+ }
+
+ exynos5_i2c_init(i2c);
+ clk_disable_unprepare(i2c->clk);
+ i2c->suspended = 0;
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+ .suspend_noirq = exynos5_i2c_suspend_noirq,
+ .resume_noirq = exynos5_i2c_resume_noirq,
+ .freeze_noirq = exynos5_i2c_suspend_noirq,
+ .thaw_noirq = exynos5_i2c_resume_noirq,
+ .poweroff_noirq = exynos5_i2c_suspend_noirq,
+ .restore_noirq = exynos5_i2c_resume_noirq,
+#endif
+};
+
+static struct platform_driver exynos5_i2c_driver = {
+ .probe = exynos5_i2c_probe,
+ .remove = exynos5_i2c_remove,
+ .driver = {
+ .name = "exynos5-hsi2c",
+ .pm = &exynos5_i2c_dev_pm_ops,
+ .of_match_table = exynos5_i2c_match,
+ },
+};
+
+module_platform_driver(exynos5_i2c_driver);
+
+MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver");
+MODULE_AUTHOR("Naveen Krishna Chatradhi, <ch.naveen@samsung.com>");
+MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff