Merge "i2c-qup: improve the bus recovery procedure in qup i2c driver" (5b5abd71) · Commits · e / devices / android_kernel_sony_msm8994

drivers/i2c/busses/i2c-qup.c

+21 −4

Original line number	Diff line number	Diff line
		@@ -142,6 +142,7 @@ enum msm_i2c_state {
		#define I2C_STATUS_CLK_STATE 13
		#define QUP_OUT_FIFO_NOT_EMPTY 0x10
		#define I2C_GPIOS_DT_CNT (2) /* sda and scl */
		#define I2C_QUP_MAX_BUS_RECOVERY_RETRY 10

		/* Register:QUP_I2C_MASTER_CLK_CTL field setters */
		#define QUP_I2C_SCL_NOISE_REJECTION(reg_val, noise_rej_val) \
		@@ -937,14 +938,13 @@ static int qup_i2c_reset(struct qup_i2c_dev *dev)
		return ret;
		}

		static int qup_i2c_recover_bus_busy(struct qup_i2c_dev *dev)
		static int qup_i2c_try_recover_bus_busy(struct qup_i2c_dev *dev)
		{
		int ret;
		u32 status;
		ulong min_sleep_usec;

		disable_irq(dev->err_irq);
		dev_info(dev->dev, "Executing bus recovery procedure (9 clk pulse)\n");

		qup_i2c_reset(dev);

		@@ -972,14 +972,31 @@ static int qup_i2c_recover_bus_busy(struct qup_i2c_dev *dev)
		usleep_range(min_sleep_usec, min_sleep_usec * 10);

		status = readl_relaxed(dev->base + QUP_I2C_STATUS);
		dev_info(dev->dev, "Bus recovery %s\n",
		(status & I2C_STATUS_BUS_ACTIVE) ? "fail" : "success");

		recovery_end:
		enable_irq(dev->err_irq);
		return ret;
		}

		static void qup_i2c_recover_bus_busy(struct qup_i2c_dev *dev)
		{
		u32 bus_clr, bus_active, status;
		int retry = 0;
		dev_info(dev->dev, "Executing bus recovery procedure (9 clk pulse)\n");

		do {
		qup_i2c_try_recover_bus_busy(dev);
		bus_clr = readl_relaxed(dev->base + QUP_I2C_MASTER_BUS_CLR);
		status = readl_relaxed(dev->base + QUP_I2C_STATUS);
		bus_active = status & I2C_STATUS_BUS_ACTIVE;
		if (++retry >= I2C_QUP_MAX_BUS_RECOVERY_RETRY)
		break;
		} while (bus_clr \|\| bus_active);

		dev_info(dev->dev, "Bus recovery %s after %d retries\n",
		(bus_clr \|\| bus_active) ? "fail" : "success", retry);
		}

		static int
		qup_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
		{