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Commit dbe6ca08 authored by Gilad Avidov's avatar Gilad Avidov
Browse files

i2c-msm-v2: add wait time to let recovery complete 



bus recovery procedure requires time to complete prior to
moving to reset state.

Change-Id: I0773bb3161769b87e4513432b8c65b8c3d24f777
Signed-off-by: default avatarAnkit Gupta <ankgupta@codeaurora.org>
Signed-off-by: default avatarAvidov Gilad <gavidov@codeaurora.org>
parent 8b606f17

drivers/i2c/busses/i2c-msm-v2.c

+26 −6
Original line number Diff line number Diff line
@@ -2045,9 +2045,14 @@ static bool i2c_msm_qup_slv_holds_bus(struct i2c_msm_ctrl *ctrl) 
{

	u32 status = readl_relaxed(ctrl->rsrcs.base + QUP_I2C_STATUS);



	return  !(status & QUP_I2C_SDA) &&

	bool slv_holds_bus =	!(status & QUP_I2C_SDA) &&

				(status & QUP_BUS_ACTIVE) &&

				!(status & QUP_BUS_MASTER);

	if (slv_holds_bus)

		dev_info(ctrl->dev,

			"bus lines held low by a slave detected\n");



	return slv_holds_bus;

}



/*
@@ -2470,6 +2475,7 @@ static int i2c_msm_qup_init(struct i2c_msm_ctrl *ctrl) 
static bool i2c_msm_qup_do_bus_clear(struct i2c_msm_ctrl *ctrl)

{

	int ret;

	ulong min_sleep_usec;

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



	/* call i2c_msm_qup_init() to set core in idle state */
@@ -2477,15 +2483,29 @@ static bool i2c_msm_qup_do_bus_clear(struct i2c_msm_ctrl *ctrl) 
	if (ret)

		return ret;



	/* call i2c_msm_qup_xfer_init_run_state() to set clock dividers */

	i2c_msm_qup_xfer_init_run_state(ctrl);



	/* must be in run state for bus clear */

	ret = i2c_msm_qup_state_set(ctrl, QUP_STATE_RUN);

	if (ret)

		return ret;



	/*

	 * call i2c_msm_qup_xfer_init_run_state() to set clock dividers.

	 * the dividers are necessary for bus clear.

	 */

	i2c_msm_qup_xfer_init_run_state(ctrl);



	writel_relaxed(0x1, ctrl->rsrcs.base + QUP_I2C_MASTER_BUS_CLR);



	/*

	 * wait for recovery (9 clock pulse cycles) to complete.

	 * min_time = 9 clock *10  (1000% margin)

	 * max_time = 10* min_time

	 */

	min_sleep_usec =

	  max_t(ulong, (9 * 10 * USEC_PER_SEC) / ctrl->rsrcs.clk_freq_out, 100);



	usleep_range(min_sleep_usec, min_sleep_usec * 10);



	return 0;

}