This patch adds the I2C controller driver for Spreadtrum SC9860 platform.

Signed-off-by: Baolin Wang <baolin.w...@spreadtrum.com>
Reviewed-by: Andy Shevchenko <andy.shevche...@gmail.com>
---
Changes since v4:
 - Remove dump registers function.
 - Change 'unsigned int' to 'u32' type.
 - Invert ack logic to make it clear.
 - Modify some comments and error message.

Changes since v3:
 - Use SPDX-License-Identifier tag instead.

Changes since v2:
 - Remove some redundant comments and parens.
 - Define macros instead of magic number.
 - Add some comments to explain clock formula.
 - Change of_clk_get_by_name() to devm_clk_get().
 - Deal with other frequency.
 - Change register definiton to low case.
 - Change is_last_msg to boolean.
 - Other optimization.

Changes sice v1:
 - Power on I2C device in probe().
 - Remove redundant macros and usb __maybe_unused.
 - Remove redundant 'of_match_ptr'.
 - Modify return values and check the return value for 'clk_prepare_enable'.
---
 drivers/i2c/busses/Kconfig    |    7 +
 drivers/i2c/busses/Makefile   |    1 +
 drivers/i2c/busses/i2c-sprd.c |  646 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 654 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-sprd.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 1006b23..64729ac 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -900,6 +900,13 @@ config I2C_SIRF
          This driver can also be built as a module.  If so, the module
          will be called i2c-sirf.
 
+config I2C_SPRD
+       bool "Spreadtrum I2C interface"
+       depends on ARCH_SPRD
+       help
+         If you say yes to this option, support will be included for the
+         Spreadtrum I2C interface.
+
 config I2C_ST
        tristate "STMicroelectronics SSC I2C support"
        depends on ARCH_STI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 1b2fc81..505f74a 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -89,6 +89,7 @@ obj-$(CONFIG_I2C_SH7760)      += i2c-sh7760.o
 obj-$(CONFIG_I2C_SH_MOBILE)    += i2c-sh_mobile.o
 obj-$(CONFIG_I2C_SIMTEC)       += i2c-simtec.o
 obj-$(CONFIG_I2C_SIRF)         += i2c-sirf.o
+obj-$(CONFIG_I2C_SPRD)         += i2c-sprd.o
 obj-$(CONFIG_I2C_ST)           += i2c-st.o
 obj-$(CONFIG_I2C_STM32F4)      += i2c-stm32f4.o
 obj-$(CONFIG_I2C_STU300)       += i2c-stu300.o
diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
new file mode 100644
index 0000000..22e08ae
--- /dev/null
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -0,0 +1,646 @@
+/*
+ * Copyright (C) 2017 Spreadtrum Communications Inc.
+ *
+ * SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#define I2C_CTL                        0x00
+#define I2C_ADDR_CFG           0x04
+#define I2C_COUNT              0x08
+#define I2C_RX                 0x0c
+#define I2C_TX                 0x10
+#define I2C_STATUS             0x14
+#define I2C_HSMODE_CFG         0x18
+#define I2C_VERSION            0x1c
+#define ADDR_DVD0              0x20
+#define ADDR_DVD1              0x24
+#define ADDR_STA0_DVD          0x28
+#define ADDR_RST               0x2c
+
+/* I2C_CTL */
+#define STP_EN                 BIT(20)
+#define FIFO_AF_LVL_MASK       GENMASK(19, 16)
+#define FIFO_AF_LVL            16
+#define FIFO_AE_LVL_MASK       GENMASK(15, 12)
+#define FIFO_AE_LVL            12
+#define I2C_DMA_EN             BIT(11)
+#define FULL_INTEN             BIT(10)
+#define EMPTY_INTEN            BIT(9)
+#define I2C_DVD_OPT            BIT(8)
+#define I2C_OUT_OPT            BIT(7)
+#define I2C_TRIM_OPT           BIT(6)
+#define I2C_HS_MODE            BIT(4)
+#define I2C_MODE               BIT(3)
+#define I2C_EN                 BIT(2)
+#define I2C_INT_EN             BIT(1)
+#define I2C_START              BIT(0)
+
+/* I2C_STATUS */
+#define SDA_IN                 BIT(21)
+#define SCL_IN                 BIT(20)
+#define FIFO_FULL              BIT(4)
+#define FIFO_EMPTY             BIT(3)
+#define I2C_INT                        BIT(2)
+#define I2C_RX_ACK             BIT(1)
+#define I2C_BUSY               BIT(0)
+
+/* ADDR_RST */
+#define I2C_RST                        BIT(0)
+
+#define I2C_FIFO_DEEP          12
+#define I2C_FIFO_FULL_THLD     15
+#define I2C_FIFO_EMPTY_THLD    4
+#define I2C_DATA_STEP          8
+#define I2C_ADDR_DVD0_CALC(high, low)  \
+       ((((high) & GENMASK(15, 0)) << 16) | ((low) & GENMASK(15, 0)))
+#define I2C_ADDR_DVD1_CALC(high, low)  \
+       (((high) & GENMASK(31, 16)) | (((low) & GENMASK(31, 16)) >> 16))
+
+/* timeout (ms) for pm runtime autosuspend */
+#define SPRD_I2C_PM_TIMEOUT    1000
+
+/* SPRD i2c data structure */
+struct sprd_i2c {
+       struct i2c_adapter adap;
+       struct device *dev;
+       void __iomem *base;
+       struct i2c_msg *msg;
+       struct clk *clk;
+       u32 src_clk;
+       u32 bus_freq;
+       struct completion complete;
+       u8 *buf;
+       u32 count;
+       int irq;
+       int err;
+};
+
+static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
+{
+       writel(count, i2c_dev->base + I2C_COUNT);
+}
+
+static void sprd_i2c_send_stop(struct sprd_i2c *i2c_dev, int stop)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       if (stop)
+               writel(tmp & ~STP_EN, i2c_dev->base + I2C_CTL);
+       else
+               writel(tmp | STP_EN, i2c_dev->base + I2C_CTL);
+}
+
+static void sprd_i2c_clear_start(struct sprd_i2c *i2c_dev)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       writel(tmp & ~I2C_START, i2c_dev->base + I2C_CTL);
+}
+
+static void sprd_i2c_clear_ack(struct sprd_i2c *i2c_dev)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_STATUS);
+
+       writel(tmp & ~I2C_RX_ACK, i2c_dev->base + I2C_STATUS);
+}
+
+static void sprd_i2c_clear_irq(struct sprd_i2c *i2c_dev)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_STATUS);
+
+       writel(tmp & ~I2C_INT, i2c_dev->base + I2C_STATUS);
+}
+
+static void sprd_i2c_reset_fifo(struct sprd_i2c *i2c_dev)
+{
+       writel(I2C_RST, i2c_dev->base + ADDR_RST);
+}
+
+static void sprd_i2c_set_devaddr(struct sprd_i2c *i2c_dev, struct i2c_msg *m)
+{
+       writel(m->addr << 1, i2c_dev->base + I2C_ADDR_CFG);
+}
+
+static void sprd_i2c_write_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
+{
+       u32 i;
+
+       for (i = 0; i < len; i++)
+               writeb(buf[i], i2c_dev->base + I2C_TX);
+}
+
+static void sprd_i2c_read_bytes(struct sprd_i2c *i2c_dev, u8 *buf, u32 len)
+{
+       u32 i;
+
+       for (i = 0; i < len; i++)
+               buf[i] = readb(i2c_dev->base + I2C_RX);
+}
+
+static void sprd_i2c_set_full_thld(struct sprd_i2c *i2c_dev, u32 full_thld)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       tmp &= ~FIFO_AF_LVL_MASK;
+       tmp |= full_thld << FIFO_AF_LVL;
+       writel(tmp, i2c_dev->base + I2C_CTL);
+};
+
+static void sprd_i2c_set_empty_thld(struct sprd_i2c *i2c_dev, u32 empty_thld)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       tmp &= ~FIFO_AE_LVL_MASK;
+       tmp |= empty_thld << FIFO_AE_LVL;
+       writel(tmp, i2c_dev->base + I2C_CTL);
+};
+
+static void sprd_i2c_set_fifo_full_int(struct sprd_i2c *i2c_dev, int enable)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       if (enable)
+               tmp |= FULL_INTEN;
+       else
+               tmp &= ~FULL_INTEN;
+
+       writel(tmp, i2c_dev->base + I2C_CTL);
+};
+
+static void sprd_i2c_set_fifo_empty_int(struct sprd_i2c *i2c_dev, int enable)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       if (enable)
+               tmp |= EMPTY_INTEN;
+       else
+               tmp &= ~EMPTY_INTEN;
+
+       writel(tmp, i2c_dev->base + I2C_CTL);
+};
+
+static void sprd_i2c_opt_start(struct sprd_i2c *i2c_dev)
+{
+       u32 tmp = readl(i2c_dev->base + I2C_CTL);
+
+       writel(tmp | I2C_START, i2c_dev->base + I2C_CTL);
+}
+
+static void sprd_i2c_opt_mode(struct sprd_i2c *i2c_dev, int rw)
+{
+       u32 cmd = readl(i2c_dev->base + I2C_CTL) & ~I2C_MODE;
+
+       writel(cmd | rw << 3, i2c_dev->base + I2C_CTL);
+}
+
+static void sprd_i2c_data_transfer(struct sprd_i2c *i2c_dev)
+{
+       u32 i2c_count = i2c_dev->count;
+       u32 need_tran = i2c_count <= I2C_FIFO_DEEP ? i2c_count : I2C_FIFO_DEEP;
+       struct i2c_msg *msg = i2c_dev->msg;
+
+       if (msg->flags & I2C_M_RD) {
+               sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, I2C_FIFO_FULL_THLD);
+               i2c_dev->count -= I2C_FIFO_FULL_THLD;
+               i2c_dev->buf += I2C_FIFO_FULL_THLD;
+
+               /*
+                * If the read data count is larger than rx fifo full threshold,
+                * we should enable the rx fifo full interrupt to read data
+                * again.
+                */
+               if (i2c_dev->count >= I2C_FIFO_FULL_THLD)
+                       sprd_i2c_set_fifo_full_int(i2c_dev, 1);
+       } else {
+               sprd_i2c_write_bytes(i2c_dev, i2c_dev->buf, need_tran);
+               i2c_dev->buf += need_tran;
+               i2c_dev->count -= need_tran;
+
+               /*
+                * If the write data count is arger than tx fifo depth which
+                * means we can not write all data in one time, then we should
+                * enable the tx fifo empty interrupt to write again.
+                */
+               if (i2c_count > I2C_FIFO_DEEP)
+                       sprd_i2c_set_fifo_empty_int(i2c_dev, 1);
+       }
+}
+
+static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,
+                              struct i2c_msg *msg, bool is_last_msg)
+{
+       struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
+
+       i2c_dev->msg = msg;
+       i2c_dev->buf = msg->buf;
+       i2c_dev->count = msg->len;
+
+       reinit_completion(&i2c_dev->complete);
+       sprd_i2c_reset_fifo(i2c_dev);
+       sprd_i2c_set_devaddr(i2c_dev, msg);
+       sprd_i2c_set_count(i2c_dev, msg->len);
+
+       if (msg->flags & I2C_M_RD) {
+               sprd_i2c_opt_mode(i2c_dev, 1);
+               sprd_i2c_send_stop(i2c_dev, 1);
+       } else {
+               sprd_i2c_opt_mode(i2c_dev, 0);
+               sprd_i2c_send_stop(i2c_dev, !!is_last_msg);
+       }
+
+       /*
+        * We should enable rx fifo full interrupt to get data when receiving
+        * full data.
+        */
+       if (msg->flags & I2C_M_RD)
+               sprd_i2c_set_fifo_full_int(i2c_dev, 1);
+       else
+               sprd_i2c_data_transfer(i2c_dev);
+
+       sprd_i2c_opt_start(i2c_dev);
+
+       wait_for_completion(&i2c_dev->complete);
+
+       return i2c_dev->err;
+}
+
+static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
+                               struct i2c_msg *msgs, int num)
+{
+       struct sprd_i2c *i2c_dev = i2c_adap->algo_data;
+       int im, ret;
+
+       ret = pm_runtime_get_sync(i2c_dev->dev);
+       if (ret < 0)
+               return ret;
+
+       for (im = 0; im < num - 1; im++) {
+               ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im], 0);
+               if (ret)
+                       goto err_msg;
+       }
+
+       ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im++], 1);
+
+err_msg:
+       pm_runtime_mark_last_busy(i2c_dev->dev);
+       pm_runtime_put_autosuspend(i2c_dev->dev);
+
+       return ret < 0 ? ret : im;
+}
+
+static u32 sprd_i2c_func(struct i2c_adapter *adap)
+{
+       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm sprd_i2c_algo = {
+       .master_xfer = sprd_i2c_master_xfer,
+       .functionality = sprd_i2c_func,
+};
+
+static void sprd_i2c_set_clk(struct sprd_i2c *i2c_dev, u32 freq)
+{
+       u32 apb_clk = i2c_dev->src_clk;
+       /*
+        * From I2C databook, the prescale calculation formula:
+        * prescale = freq_i2c / (4 * freq_scl) - 1;
+        */
+       u32 i2c_dvd = apb_clk / (4 * freq) - 1;
+       /*
+        * From I2C databook, the high period of SCL clock is recommended as
+        * 40% (2/5), and the low period of SCL clock is recommended as 60%
+        * (3/5), then the formula should be:
+        * high = (prescale * 2 * 2) / 5
+        * low = (prescale * 2 * 3) / 5
+        */
+       u32 high = ((i2c_dvd << 1) * 2) / 5;
+       u32 low = ((i2c_dvd << 1) * 3) / 5;
+       u32 div0 = I2C_ADDR_DVD0_CALC(high, low);
+       u32 div1 = I2C_ADDR_DVD1_CALC(high, low);
+
+       writel(div0, i2c_dev->base + ADDR_DVD0);
+       writel(div1, i2c_dev->base + ADDR_DVD1);
+
+       /* Start hold timing = hold time(us) * source clock */
+       if (freq == 400000)
+               writel((6 * apb_clk) / 10000000, i2c_dev->base + ADDR_STA0_DVD);
+       else if (freq == 100000)
+               writel((4 * apb_clk) / 1000000, i2c_dev->base + ADDR_STA0_DVD);
+}
+
+static void sprd_i2c_enable(struct sprd_i2c *i2c_dev)
+{
+       u32 tmp = I2C_DVD_OPT;
+
+       writel(tmp, i2c_dev->base + I2C_CTL);
+
+       sprd_i2c_set_full_thld(i2c_dev, I2C_FIFO_FULL_THLD);
+       sprd_i2c_set_empty_thld(i2c_dev, I2C_FIFO_EMPTY_THLD);
+
+       sprd_i2c_set_clk(i2c_dev, i2c_dev->bus_freq);
+       sprd_i2c_reset_fifo(i2c_dev);
+       sprd_i2c_clear_irq(i2c_dev);
+
+       tmp = readl(i2c_dev->base + I2C_CTL);
+       writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL);
+}
+
+static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
+{
+       struct sprd_i2c *i2c_dev = dev_id;
+       struct i2c_msg *msg = i2c_dev->msg;
+       bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
+       u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
+       u32 i2c_tran;
+
+       if (msg->flags & I2C_M_RD)
+               i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
+       else
+               i2c_tran = i2c_count;
+
+       /*
+        * If we got one ACK from slave when writing data, and we did not
+        * finish this transmission (i2c_tran is not zero), then we should
+        * continue to write data.
+        *
+        * For reading data, ack is always true, if i2c_tran is not 0 which
+        * means we still need to contine to read data from slave.
+        */
+       if (i2c_tran && ack) {
+               sprd_i2c_data_transfer(i2c_dev);
+               return IRQ_HANDLED;
+       }
+
+       i2c_dev->err = 0;
+
+       /*
+        * If we did not get one ACK from slave when writing data, we should
+        * return -EIO to notify users.
+        */
+       if (!ack)
+               i2c_dev->err = -EIO;
+       else if (msg->flags & I2C_M_RD && i2c_dev->count)
+               sprd_i2c_read_bytes(i2c_dev, i2c_dev->buf, i2c_dev->count);
+
+       /* Transmission is done and clear ack and start operation */
+       sprd_i2c_clear_ack(i2c_dev);
+       sprd_i2c_clear_start(i2c_dev);
+       complete(&i2c_dev->complete);
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t sprd_i2c_isr(int irq, void *dev_id)
+{
+       struct sprd_i2c *i2c_dev = dev_id;
+       struct i2c_msg *msg = i2c_dev->msg;
+       u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
+       bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
+       u32 i2c_tran;
+
+       if (msg->flags & I2C_M_RD)
+               i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
+       else
+               i2c_tran = i2c_count;
+
+       /*
+        * If we did not get one ACK from slave when writing data, then we
+        * should finish this transmission since we got some errors.
+        *
+        * When writing data, if i2c_tran == 0 which means we have writen
+        * done all data, then we can finish this transmission.
+        *
+        * When reading data, if conut < rx fifo full threshold, which
+        * means we can read all data in one time, then we can finish this
+        * transmission too.
+        */
+       if (!i2c_tran || !ack) {
+               sprd_i2c_clear_start(i2c_dev);
+               sprd_i2c_clear_irq(i2c_dev);
+       }
+
+       sprd_i2c_set_fifo_empty_int(i2c_dev, 0);
+       sprd_i2c_set_fifo_full_int(i2c_dev, 0);
+
+       return IRQ_WAKE_THREAD;
+}
+
+static int sprd_i2c_clk_init(struct sprd_i2c *i2c_dev)
+{
+       struct clk *clk_i2c, *clk_parent;
+
+       clk_i2c = devm_clk_get(i2c_dev->dev, "i2c");
+       if (IS_ERR(clk_i2c)) {
+               dev_warn(i2c_dev->dev, "i2c%d can't get the i2c clock\n",
+                        i2c_dev->adap.nr);
+               clk_i2c = NULL;
+       }
+
+       clk_parent = devm_clk_get(i2c_dev->dev, "source");
+       if (IS_ERR(clk_parent)) {
+               dev_warn(i2c_dev->dev, "i2c%d can't get the source clock\n",
+                        i2c_dev->adap.nr);
+               clk_parent = NULL;
+       }
+
+       if (clk_set_parent(clk_i2c, clk_parent))
+               i2c_dev->src_clk = clk_get_rate(clk_i2c);
+       else
+               i2c_dev->src_clk = 26000000;
+
+       dev_dbg(i2c_dev->dev, "i2c%d set source clock is %d\n",
+               i2c_dev->adap.nr, i2c_dev->src_clk);
+
+       i2c_dev->clk = devm_clk_get(i2c_dev->dev, "enable");
+       if (IS_ERR(i2c_dev->clk)) {
+               dev_warn(i2c_dev->dev, "i2c%d can't get the enable clock\n",
+                        i2c_dev->adap.nr);
+               i2c_dev->clk = NULL;
+       }
+
+       return 0;
+}
+
+static int sprd_i2c_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct sprd_i2c *i2c_dev;
+       struct resource *res;
+       u32 prop;
+       int ret;
+
+       pdev->id = of_alias_get_id(dev->of_node, "i2c");
+
+       i2c_dev = devm_kzalloc(dev, sizeof(struct sprd_i2c), GFP_KERNEL);
+       if (!i2c_dev)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       i2c_dev->base = devm_ioremap_resource(dev, res);
+       if (IS_ERR(i2c_dev->base))
+               return PTR_ERR(i2c_dev->base);
+
+       i2c_dev->irq = platform_get_irq(pdev, 0);
+       if (i2c_dev->irq < 0) {
+               dev_err(&pdev->dev, "failed to get irq resource\n");
+               return i2c_dev->irq;
+       }
+
+       i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
+       init_completion(&i2c_dev->complete);
+       snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
+                "%s", "sprd-i2c");
+
+       i2c_dev->bus_freq = 100000;
+       i2c_dev->adap.owner = THIS_MODULE;
+       i2c_dev->dev = dev;
+       i2c_dev->adap.retries = 3;
+       i2c_dev->adap.algo = &sprd_i2c_algo;
+       i2c_dev->adap.algo_data = i2c_dev;
+       i2c_dev->adap.dev.parent = dev;
+       i2c_dev->adap.nr = pdev->id;
+       i2c_dev->adap.dev.of_node = dev->of_node;
+
+       if (!of_property_read_u32(dev->of_node, "clock-frequency", &prop))
+               i2c_dev->bus_freq = prop;
+
+       /* We only support 100k and 400k now, otherwise will return error. */
+       if (i2c_dev->bus_freq != 100000 && i2c_dev->bus_freq != 400000)
+               return -EINVAL;
+
+       sprd_i2c_clk_init(i2c_dev);
+       platform_set_drvdata(pdev, i2c_dev);
+
+       ret = clk_prepare_enable(i2c_dev->clk);
+       if (ret)
+               return ret;
+
+       sprd_i2c_enable(i2c_dev);
+
+       pm_runtime_set_autosuspend_delay(i2c_dev->dev, SPRD_I2C_PM_TIMEOUT);
+       pm_runtime_use_autosuspend(i2c_dev->dev);
+       pm_runtime_set_active(i2c_dev->dev);
+       pm_runtime_enable(i2c_dev->dev);
+
+       ret = pm_runtime_get_sync(i2c_dev->dev);
+       if (ret < 0)
+               goto err_rpm_put;
+
+       ret = devm_request_threaded_irq(dev, i2c_dev->irq,
+               sprd_i2c_isr, sprd_i2c_isr_thread,
+               IRQF_NO_SUSPEND | IRQF_ONESHOT,
+               pdev->name, i2c_dev);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to request irq %d\n", i2c_dev->irq);
+               goto err_rpm_put;
+       }
+
+       ret = i2c_add_numbered_adapter(&i2c_dev->adap);
+       if (ret) {
+               dev_err(&pdev->dev, "add adapter failed\n");
+               goto err_rpm_put;
+       }
+
+       pm_runtime_mark_last_busy(i2c_dev->dev);
+       pm_runtime_put_autosuspend(i2c_dev->dev);
+       return 0;
+
+err_rpm_put:
+       pm_runtime_put_noidle(i2c_dev->dev);
+       pm_runtime_disable(i2c_dev->dev);
+       clk_disable_unprepare(i2c_dev->clk);
+       return ret;
+}
+
+static int sprd_i2c_remove(struct platform_device *pdev)
+{
+       struct sprd_i2c *i2c_dev = platform_get_drvdata(pdev);
+       int ret;
+
+       ret = pm_runtime_get_sync(i2c_dev->dev);
+       if (ret < 0)
+               return ret;
+
+       i2c_del_adapter(&i2c_dev->adap);
+       clk_disable_unprepare(i2c_dev->clk);
+
+       pm_runtime_put_noidle(i2c_dev->dev);
+       pm_runtime_disable(i2c_dev->dev);
+
+       return 0;
+}
+
+static int __maybe_unused sprd_i2c_suspend_noirq(struct device *pdev)
+{
+       return pm_runtime_force_suspend(pdev);
+}
+
+static int __maybe_unused sprd_i2c_resume_noirq(struct device *pdev)
+{
+       return pm_runtime_force_resume(pdev);
+}
+
+static int __maybe_unused sprd_i2c_runtime_suspend(struct device *pdev)
+{
+       struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
+
+       clk_disable_unprepare(i2c_dev->clk);
+
+       return 0;
+}
+
+static int __maybe_unused sprd_i2c_runtime_resume(struct device *pdev)
+{
+       struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
+       int ret;
+
+       ret = clk_prepare_enable(i2c_dev->clk);
+       if (ret)
+               return ret;
+
+       sprd_i2c_enable(i2c_dev);
+
+       return 0;
+}
+
+static const struct dev_pm_ops sprd_i2c_pm_ops = {
+       SET_RUNTIME_PM_OPS(sprd_i2c_runtime_suspend,
+                          sprd_i2c_runtime_resume, NULL)
+
+       SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sprd_i2c_suspend_noirq,
+                                     sprd_i2c_resume_noirq)
+};
+
+static const struct of_device_id sprd_i2c_of_match[] = {
+       { .compatible = "sprd,sc9860-i2c", },
+};
+
+static struct platform_driver sprd_i2c_driver = {
+       .probe = sprd_i2c_probe,
+       .remove = sprd_i2c_remove,
+       .driver = {
+                  .name = "sprd-i2c",
+                  .of_match_table = sprd_i2c_of_match,
+                  .pm = &sprd_i2c_pm_ops,
+       },
+};
+
+static int sprd_i2c_init(void)
+{
+       return platform_driver_register(&sprd_i2c_driver);
+}
+arch_initcall_sync(sprd_i2c_init);
-- 
1.7.9.5

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