[PATCH v1 5/8] scsi: ufs: qcom: Expose the reset controller for PHY

Evan Green
2019-01-11T23:02:13Z

Expose a reset controller that the phy can use to perform its
initialization in a single callback.

Also, change the use of the phy functions from ufs-qcom such that
phy_poweron actually fires up the phy, and phy_poweroff actually
powers it down.

Signed-off-by: Evan Green <evgreen@chromium.org>

---
Note: This change depends on the remaining changes in this series,
since UFS PHY reset now needs to be done by the PHY driver.

drivers/scsi/ufs/Kconfig | 1 +
drivers/scsi/ufs/ufs-qcom.c | 110 +++++++++++++++++++++---------------
drivers/scsi/ufs/ufs-qcom.h | 4 ++
3 files changed, 71 insertions(+), 44 deletions(-)

diff --git a/drivers/scsi/ufs/Kconfig b/drivers/scsi/ufs/Kconfig
index 2ddbb26d9c265..63c5c4115981f 100644
--- a/drivers/scsi/ufs/Kconfig
+++ b/drivers/scsi/ufs/Kconfig
@@ -100,6 +100,7 @@ config SCSI_UFS_QCOM
tristate "QCOM specific hooks to UFS controller platform driver"
depends on SCSI_UFSHCD_PLATFORM && ARCH_QCOM
select PHY_QCOM_UFS
+ select RESET_CONTROLLER
help
This selects the QCOM specific additions to UFSHCD platform driver.
UFS host on QCOM needs some vendor specific configuration before
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 3aeadb14aae1e..db46f9a64b54c 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -16,6 +16,7 @@
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>
+#include <linux/reset.h>

#include "ufshcd.h"
#include "ufshcd-pltfrm.h"
@@ -49,6 +50,11 @@ static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
u32 clk_cycles);

+static struct ufs_qcom_host *rcdev_to_ufs_host(struct reset_controller_dev *rcd)
+{
+ return container_of(rcd, struct ufs_qcom_host, rcdev);
+}
+
static void ufs_qcom_dump_regs_wrapper(struct ufs_hba *hba, int offset, int len,
const char *prefix, void *priv)
{
@@ -255,11 +261,6 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
if (is_rate_B)
phy_set_mode(phy, PHY_MODE_UFS_HS_B);

- /* Assert PHY reset and apply PHY calibration values */
- ufs_qcom_assert_reset(hba);
- /* provide 1ms delay to let the reset pulse propagate */
- usleep_range(1000, 1100);
-
/* phy initialization - calibrate the phy */
ret = phy_init(phy);
if (ret) {
@@ -268,15 +269,6 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
goto out;
}

- /* De-assert PHY reset and start serdes */
- ufs_qcom_deassert_reset(hba);
-
- /*
- * after reset deassertion, phy will need all ref clocks,
- * voltage, current to settle down before starting serdes.
- */
- usleep_range(1000, 1100);
-
/* power on phy - start serdes and phy's power and clocks */
ret = phy_power_on(phy);
if (ret) {
@@ -290,7 +282,6 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
return 0;

out_disable_phy:
- ufs_qcom_assert_reset(hba);
phy_exit(phy);
out:
return ret;
@@ -554,21 +545,10 @@ static int ufs_qcom_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
ufs_qcom_disable_lane_clks(host);
phy_power_off(phy);

- /* Assert PHY soft reset */
- ufs_qcom_assert_reset(hba);
- goto out;
- }
-
- /*
- * If UniPro link is not active, PHY ref_clk, main PHY analog power
- * rail and low noise analog power rail for PLL can be switched off.
- */
- if (!ufs_qcom_is_link_active(hba)) {
+ } else if (!ufs_qcom_is_link_active(hba)) {
ufs_qcom_disable_lane_clks(host);
- phy_power_off(phy);
}

-out:
return ret;
}

@@ -578,21 +558,26 @@ static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
struct phy *phy = host->generic_phy;
int err;

- err = phy_power_on(phy);
- if (err) {
- dev_err(hba->dev, "%s: failed enabling regs, err = %d\n",
- __func__, err);
- goto out;
- }
+ if (ufs_qcom_is_link_off(hba)) {
+ err = phy_power_on(phy);
+ if (err) {
+ dev_err(hba->dev, "%s: failed enabling regs, err = %d\n",
+ __func__, err);
+ return err;
+ }

- err = ufs_qcom_enable_lane_clks(host);
- if (err)
- goto out;
+ err = ufs_qcom_enable_lane_clks(host);
+ if (err)
+ return err;

- hba->is_sys_suspended = false;
+ } else if (!ufs_qcom_is_link_active(hba)) {
+ err = ufs_qcom_enable_lane_clks(host);
+ if (err)
+ return err;
+ }

-out:
- return err;
+ hba->is_sys_suspended = false;
+ return 0;
}

struct ufs_qcom_dev_params {
@@ -1118,8 +1103,6 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
return 0;

if (on && (status == POST_CHANGE)) {
- phy_power_on(host->generic_phy);
-
/* enable the device ref clock for HS mode*/
if (ufshcd_is_hs_mode(&hba->pwr_info))
ufs_qcom_dev_ref_clk_ctrl(host, true);
@@ -1131,9 +1114,6 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
if (!ufs_qcom_is_link_active(hba)) {
/* disable device ref_clk */
ufs_qcom_dev_ref_clk_ctrl(host, false);
-
- /* powering off PHY during aggressive clk gating */
- phy_power_off(host->generic_phy);
}

vote = host->bus_vote.min_bw_vote;
@@ -1147,6 +1127,39 @@ static int ufs_qcom_setup_clocks(struct ufs_hba *hba, bool on,
return err;
}

+static int
+ufs_qcom_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct ufs_qcom_host *host = rcdev_to_ufs_host(rcdev);
+
+ WARN_ON(id);
+ ufs_qcom_assert_reset(host->hba);
+ /* provide 1ms delay to let the reset pulse propagate */
+ usleep_range(1000, 1100);
+ return 0;
+}
+
+static int
+ufs_qcom_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+ struct ufs_qcom_host *host = rcdev_to_ufs_host(rcdev);
+
+ WARN_ON(id);
+ ufs_qcom_deassert_reset(host->hba);
+
+ /*
+ * after reset deassertion, phy will need all ref clocks,
+ * voltage, current to settle down before starting serdes.
+ */
+ usleep_range(1000, 1100);
+ return 0;
+}
+
+const struct reset_control_ops ufs_qcom_reset_ops = {
+ .assert = ufs_qcom_reset_assert,
+ .deassert = ufs_qcom_reset_deassert,
+};
+
#define ANDROID_BOOT_DEV_MAX 30
static char android_boot_dev[ANDROID_BOOT_DEV_MAX];

@@ -1191,6 +1204,15 @@ static int ufs_qcom_init(struct ufs_hba *hba)
host->hba = hba;
ufshcd_set_variant(hba, host);

+ /* Fire up the reset controller. Failure here is non-fatal. */
+ host->rcdev.of_node = dev->of_node;
+ host->rcdev.ops = &ufs_qcom_reset_ops;
+ host->rcdev.owner = dev->driver->owner;
+ host->rcdev.nr_resets = 1;
+ err = devm_reset_controller_register(dev, &host->rcdev);
+ if (err)
+ dev_warn(dev, "Failed to register reset controller\n");
+
/*
* voting/devoting device ref_clk source is time consuming hence
* skip devoting it during aggressive clock gating. This clock
diff --git a/drivers/scsi/ufs/ufs-qcom.h b/drivers/scsi/ufs/ufs-qcom.h
index c114826316eb0..68a8801857529 100644
--- a/drivers/scsi/ufs/ufs-qcom.h
+++ b/drivers/scsi/ufs/ufs-qcom.h
@@ -14,6 +14,8 @@
#ifndef UFS_QCOM_H_
#define UFS_QCOM_H_

+#include <linux/reset-controller.h>
+
#define MAX_UFS_QCOM_HOSTS 1
#define MAX_U32 (~(u32)0)
#define MPHY_TX_FSM_STATE 0x41
@@ -237,6 +239,8 @@ struct ufs_qcom_host {
/* Bitmask for enabling debug prints */
u32 dbg_print_en;
struct ufs_qcom_testbus testbus;
+
+ struct reset_controller_dev rcdev;
};

static inline u32
--
2.18.1