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Commit 8916df2e authored by Pavankumar Kondeti's avatar Pavankumar Kondeti
Browse files

USB: ice40-hcd: Implement the correct power-up sequence 



The 19.2 MHZ clock is supplied to the bridge chip from the MSM.
This clock is not required during configuration loading. Enable it
after configuration loading and before bringing the bridge chip out
of the reset. The bridge chip exits the reset by sampling the
falling edge of the reset line. As per the data book, the reset
line needs to be asserted 0 to 1 twice with 100 usec pulse width.

If the power-up sequence is failed, retry 3 times before failing the
probe.

CRs-Fixed: 643157
Change-Id: I76a95f84969b581fd65992ca7f248a761dcdfdeb
Signed-off-by: default avatarPavankumar Kondeti <pkondeti@codeaurora.org>
parent 1e51b157

drivers/usb/host/ice40-hcd.c

+87 −27
Original line number Diff line number Diff line
@@ -165,6 +165,7 @@ struct ice40_hcd { 
	struct regulator *spi_vcc;

	struct regulator *gpio_vcc;

	bool powered;

	bool clocked;



	struct dentry *dbg_root;

	bool pcd_pending;
@@ -198,6 +199,8 @@ struct ice40_hcd { 
	u8 *out_buf; /* size 1 for writing WBUF0 */

};



#define FIRMWARE_LOAD_RETRIES 3



static char fw_name[16] = "ice40.bin";

module_param_string(fw, fw_name, sizeof(fw_name), S_IRUGO | S_IWUSR);

MODULE_PARM_DESC(fw, "firmware blob file name");
@@ -1191,6 +1194,7 @@ error: 
	return ret;

}



static void ice40_spi_clock_disable(struct ice40_hcd *ihcd);

static void ice40_spi_power_off(struct ice40_hcd *ihcd);

static int ice40_bus_suspend(struct usb_hcd *hcd)

{
@@ -1218,6 +1222,7 @@ static int ice40_bus_suspend(struct usb_hcd *hcd) 
	 * current.

	 */

	ice40_spi_power_off(ihcd);

	ice40_spi_clock_disable(ihcd);



	trace_ice40_bus_suspend(1); /* successful */

	pm_relax(&ihcd->spi->dev);
@@ -1239,7 +1244,7 @@ static int ice40_bus_resume(struct usb_hcd *hcd) 
	 * update the device address only.

	 */



	for (i = 0; i < 3; i++) {

	for (i = 0; i < FIRMWARE_LOAD_RETRIES; i++) {

		ret = ice40_spi_load_fw(ihcd);

		if (!ret)

			break;
@@ -1371,27 +1376,25 @@ out: 
	return ret;

}



static void ice40_spi_power_off(struct ice40_hcd *ihcd)

static void ice40_spi_clock_disable(struct ice40_hcd *ihcd)

{

	if (!ihcd->powered)

	if (!ihcd->clocked)

		return;



	gpio_direction_output(ihcd->vcc_en_gpio, 0);

	regulator_disable(ihcd->core_vcc);

	regulator_disable(ihcd->spi_vcc);

	if (ihcd->gpio_vcc)

		regulator_disable(ihcd->gpio_vcc);

	if (ihcd->clk_en_gpio)

		gpio_direction_output(ihcd->clk_en_gpio, 0);

	if (ihcd->xo_clk)

		clk_disable_unprepare(ihcd->xo_clk);



	ihcd->powered = false;

	ihcd->clocked = false;

}



static int ice40_spi_power_up(struct ice40_hcd *ihcd)

static int ice40_spi_clock_enable(struct ice40_hcd *ihcd)

{

	int ret;

	int ret = 0;



	if (ihcd->clocked)

		goto out;



	if (ihcd->xo_clk) {

		ret = clk_prepare_enable(ihcd->xo_clk);
@@ -1404,16 +1407,48 @@ static int ice40_spi_power_up(struct ice40_hcd *ihcd) 
	if (ihcd->clk_en_gpio) {

		ret = gpio_direction_output(ihcd->clk_en_gpio, 1);

		if (ret < 0) {

			pr_err("fail to enable clk %d\n", ret);

			pr_err("fail to assert clk-en %d\n", ret);

			goto disable_xo;

		}

	}



	ihcd->clocked = true;



	return 0;



disable_xo:

	if (ihcd->xo_clk)

		clk_disable_unprepare(ihcd->xo_clk);

out:

	return ret;

}



static void ice40_spi_power_off(struct ice40_hcd *ihcd)

{

	if (!ihcd->powered)

		return;



	gpio_direction_output(ihcd->vcc_en_gpio, 0);

	regulator_disable(ihcd->core_vcc);

	regulator_disable(ihcd->spi_vcc);

	if (ihcd->gpio_vcc)

		regulator_disable(ihcd->gpio_vcc);



	ihcd->powered = false;

}



static int ice40_spi_power_up(struct ice40_hcd *ihcd)

{

	int ret = 0;



	if (ihcd->powered)

		goto out;



	if (ihcd->gpio_vcc) {

		ret = regulator_enable(ihcd->gpio_vcc); /* 1.8 V */

		if (ret < 0) {

			pr_err("fail to enable gpio vcc\n");

			goto disable_clk;

			goto out;

		}

	}
@@ -1446,12 +1481,6 @@ disable_spi_vcc: 
disable_gpio_vcc:

	if (ihcd->gpio_vcc)

		regulator_disable(ihcd->gpio_vcc);

disable_clk:

	if (ihcd->clk_en_gpio)

		gpio_direction_output(ihcd->clk_en_gpio, 0);

disable_xo:

	if (ihcd->xo_clk)

		clk_disable_unprepare(ihcd->xo_clk);

out:

	return ret;

}
@@ -1621,24 +1650,51 @@ static int ice40_spi_load_fw(struct ice40_hcd *ihcd) 
		goto power_off;

	}



	ret = ice40_spi_clock_enable(ihcd);

	if (ret < 0) {

		pr_err("fail to enable clocks %d\n", ret);

		goto power_off;

	}



	/*

	 * As per the data book, the bridge chip exits the

	 * reset state by sampling the falling edge of the

	 * reset line. Hence assert the reset from 0 to 1

	 * with 100 usec pulse width twice.

	 */

	ret = gpio_direction_output(ihcd->reset_gpio, 1);

	if (ret  < 0) {

		pr_err("fail to de-assert reset %d\n", ret);

		goto clocks_off;

	}

	udelay(100);

	ret = gpio_direction_output(ihcd->reset_gpio, 0);

	if (ret  < 0) {

		pr_err("fail to assert reset %d\n", ret);

		goto power_off;

		goto clocks_off;

	}

	udelay(50);

	udelay(100);

	ret = gpio_direction_output(ihcd->reset_gpio, 1);

	if (ret  < 0) {

		pr_err("fail to de-assert reset %d\n", ret);

		goto clocks_off;

	}

	udelay(100);



	ret = ice40_spi_reg_read(ihcd, XFRST_REG);

	pr_debug("XFRST val is %x\n", ret);

	if (!(ret & PLLOK)) {

		pr_err("The PLL2 is not synchronized\n");

		goto power_off;

		ret = -ENODEV;

		goto clocks_off;

	}



	pr_info("Firmware load success\n");



	return 0;



clocks_off:

	ice40_spi_clock_disable(ihcd);

power_off:

	ice40_spi_power_off(ihcd);

out:
@@ -1970,6 +2026,7 @@ static ssize_t ice40_dbg_cmd_write(struct file *file, const char __user *ubuf, 
		usb_hcd_poll_rh_status(ihcd->hcd);

	} else if (!strcmp(buf, "config_test")) {

		ice40_spi_power_off(ihcd);

		ice40_spi_clock_disable(ihcd);

		ret = ice40_spi_load_fw(ihcd);

		if (ret) {

			pr_err("config load failed\n");
@@ -2022,7 +2079,7 @@ out: 
static int ice40_spi_probe(struct spi_device *spi)

{

	struct ice40_hcd *ihcd;

	int ret;

	int ret, i;



	ihcd = devm_kzalloc(&spi->dev, sizeof(*ihcd), GFP_KERNEL);

	if (!ihcd) {
@@ -2089,7 +2146,11 @@ static int ice40_spi_probe(struct spi_device *spi) 
		goto destroy_wq;

	}



	for (i = 0; i < FIRMWARE_LOAD_RETRIES; i++) {

		ret = ice40_spi_load_fw(ihcd);

		if (!ret)

			break;

	}

	if (ret) {

		pr_err("fail to load fw %d\n", ret);

		goto destroy_wq;
@@ -2099,7 +2160,7 @@ static int ice40_spi_probe(struct spi_device *spi) 
	if (!ihcd->hcd) {

		pr_err("fail to alloc hcd\n");

		ret = -ENOMEM;

		goto power_off;

		goto destroy_wq;

	}

	*((struct ice40_hcd **) ihcd->hcd->hcd_priv) = ihcd;
@@ -2138,8 +2199,6 @@ static int ice40_spi_probe(struct spi_device *spi) 


put_hcd:

	usb_put_hcd(ihcd->hcd);

power_off:

	ice40_spi_power_off(ihcd);

destroy_wq:

	destroy_workqueue(ihcd->wq);

destroy_mutex:
@@ -2162,6 +2221,7 @@ static int ice40_spi_remove(struct spi_device *spi) 
	usb_put_hcd(hcd);

	destroy_workqueue(ihcd->wq);

	ice40_spi_power_off(ihcd);

	ice40_spi_clock_disable(ihcd);



	s = pinctrl_lookup_state(ihcd->pinctrl, PINCTRL_STATE_SLEEP);

	if (!IS_ERR(s))