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Commit 0cf02ecf authored by Can Guo's avatar Can Guo
Browse files

scsi: ufs-qcom: Add reset control support for host controller 



Add reset control for host controller so that host controller can be reset
as required in its power up sequence.

Change-Id: I7aae30c859426cad0c995400e747883fc60fef17
Signed-off-by: default avatarCan Guo <cang@codeaurora.org>
parent d9af7d71

drivers/scsi/ufs/ufs-qcom.c

+53 −0
Original line number Diff line number Diff line
@@ -413,6 +413,44 @@ static void ufs_qcom_select_unipro_mode(struct ufs_qcom_host *host) 
	mb();

}



/**

 * ufs_qcom_host_reset - reset host controller and PHY

 */

static int ufs_qcom_host_reset(struct ufs_hba *hba)

{

	int ret = 0;

	struct ufs_qcom_host *host = ufshcd_get_variant(hba);



	if (!host->core_reset) {

		dev_warn(hba->dev, "%s: reset control not set\n", __func__);

		goto out;

	}



	ret = reset_control_assert(host->core_reset);

	if (ret) {

		dev_err(hba->dev, "%s: core_reset assert failed, err = %d\n",

				 __func__, ret);

		goto out;

	}



	/*

	 * The hardware requirement for delay between assert/deassert

	 * is at least 3-4 sleep clock (32.7KHz) cycles, which comes to

	 * ~125us (4/32768). To be on the safe side add 200us delay.

	 */

	usleep_range(200, 210);



	ret = reset_control_deassert(host->core_reset);

	if (ret)

		dev_err(hba->dev, "%s: core_reset deassert failed, err = %d\n",

				 __func__, ret);



	usleep_range(1000, 1100);



out:

	return ret;

}



static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)

{

	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
@@ -421,6 +459,12 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba) 
	bool is_rate_B = (UFS_QCOM_LIMIT_HS_RATE == PA_HS_MODE_B)

							? true : false;



	/* Reset UFS Host Controller and PHY */

	ret = ufs_qcom_host_reset(hba);

	if (ret)

		dev_warn(hba->dev, "%s: host reset returned %d\n",

				  __func__, ret);



#ifdef CONFIG_SCSI_UFSHCD_QTI

	/* Use Rate-A for Gear4 on non-simulation platforms */

	if (hba->phy_init_g4) {
@@ -2001,6 +2045,15 @@ static int ufs_qcom_init(struct ufs_hba *hba) 
	host->hba = hba;

	ufshcd_set_variant(hba, host);



	/* Setup the reset control of HCI */

	host->core_reset = devm_reset_control_get(hba->dev, "rst");

	if (IS_ERR(host->core_reset)) {

		err = PTR_ERR(host->core_reset);

		dev_warn(dev, "Failed to get reset control %d\n", err);

		host->core_reset = NULL;

		err = 0;

	}



	/* Fire up the reset controller. Failure here is non-fatal. */

	host->rcdev.of_node = dev->of_node;

	host->rcdev.ops = &ufs_qcom_reset_ops;

drivers/scsi/ufs/ufs-qcom.h

+3 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#define UFS_QCOM_H_



#include <linux/reset-controller.h>

#include <linux/reset.h>

#include <linux/phy/phy.h>

#include "ufshcd.h"

#ifdef CONFIG_SCSI_UFSHCD_QTI
@@ -312,6 +313,8 @@ struct ufs_qcom_host { 
	u32 dbg_print_en;

	struct ufs_qcom_testbus testbus;



	/* Reset control of HCI */

	struct reset_control *core_reset;

	struct reset_controller_dev rcdev;



	struct gpio_desc *device_reset;