[PATCH v3 7/8] phy: qcom: Utilize UFS reset controller

Evan Green
2019-02-05T18:59:52Z

Move the PHY reset from ufs-qcom into the respective PHYs. This will
allow us to merge the two phases of UFS PHY initialization.

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

---

Changes in v3:
- Refactored to move reset control in a single commit (Stephen)
- Use no_pcs_sw_reset as an indicator of UFS reset in qmp-phy (Stephen).
- Assign ret = PTR_ERR() earlier, for better reuse (Stephen).

Changes in v2:
- Use devm_* to get the reset (Stephen)
- Clear ufs_reset on error getting it
- Remove needless error print (Stephen)

drivers/phy/qualcomm/phy-qcom-qmp.c | 39 ++++++++++++++++++++
drivers/phy/qualcomm/phy-qcom-ufs-i.h | 3 ++
drivers/phy/qualcomm/phy-qcom-ufs-qmp-14nm.c | 10 +++++
drivers/phy/qualcomm/phy-qcom-ufs-qmp-20nm.c | 10 +++++
drivers/phy/qualcomm/phy-qcom-ufs.c | 27 ++++++++++++++
drivers/scsi/ufs/ufs-qcom.c | 18 ---------
6 files changed, 89 insertions(+), 18 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
index daf751500232..2861c64b9bcc 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
@@ -897,6 +897,7 @@ struct qmp_phy {
* @init_count: phy common block initialization count
* @phy_initialized: indicate if PHY has been initialized
* @mode: current PHY mode
+ * @ufs_reset: optional UFS PHY reset handle
*/
struct qcom_qmp {
struct device *dev;
@@ -914,6 +915,8 @@ struct qcom_qmp {
int init_count;
bool phy_initialized;
enum phy_mode mode;
+
+ struct reset_control *ufs_reset;
};

static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
@@ -1314,6 +1317,9 @@ static int qcom_qmp_phy_com_exit(struct qcom_qmp *qmp)
return 0;
}

+ if (qmp->ufs_reset)
+ reset_control_assert(qmp->ufs_reset);
+
if (cfg->has_phy_com_ctrl) {
qphy_setbits(serdes, cfg->regs[QPHY_COM_START_CONTROL],
SERDES_START | PCS_START);
@@ -1351,6 +1357,33 @@ static int qcom_qmp_phy_init(struct phy *phy)

dev_vdbg(qmp->dev, "Initializing QMP phy\n");

+ if (cfg->no_pcs_sw_reset) {
+ /*
+ * Get UFS reset, which is delayed until now to avoid a
+ * circular dependency where UFS needs its PHY, but the PHY
+ * needs this UFS reset.
+ */
+ if (!qmp->ufs_reset) {
+ qmp->ufs_reset =
+ devm_reset_control_get_exclusive(qmp->dev,
+ "ufsphy");
+
+ if (IS_ERR(qmp->ufs_reset)) {
+ ret = PTR_ERR(qmp->ufs_reset);
+ dev_err(qmp->dev,
+ "failed to get UFS reset: %d\n",
+ ret);
+
+ qmp->ufs_reset = NULL;
+ return ret;
+ }
+ }
+
+ ret = reset_control_assert(qmp->ufs_reset);
+ if (ret)
+ goto err_lane_rst;
+ }
+
ret = qcom_qmp_phy_com_init(qphy);
if (ret)
return ret;
@@ -1384,6 +1417,12 @@ static int qcom_qmp_phy_init(struct phy *phy)

qcom_qmp_phy_configure(pcs, cfg->regs, cfg->pcs_tbl, cfg->pcs_tbl_num);

+ if (qmp->ufs_reset) {
+ ret = reset_control_deassert(qmp->ufs_reset);
+ if (ret)
+ goto err_lane_rst;
+ }
+
/*
* UFS PHY requires the deassert of software reset before serdes start.
* For UFS PHYs that do not have software reset control bits, defer
diff --git a/drivers/phy/qualcomm/phy-qcom-ufs-i.h b/drivers/phy/qualcomm/phy-qcom-ufs-i.h
index f798fb64de94..ba77348d807c 100644
--- a/drivers/phy/qualcomm/phy-qcom-ufs-i.h
+++ b/drivers/phy/qualcomm/phy-qcom-ufs-i.h
@@ -19,6 +19,7 @@
#include <linux/clk.h>
#include <linux/phy/phy.h>
#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/io.h>
@@ -101,6 +102,7 @@ struct ufs_qcom_phy {
struct ufs_qcom_phy_specific_ops *phy_spec_ops;

enum phy_mode mode;
+ struct reset_control *ufs_reset;
};

/**
@@ -132,6 +134,7 @@ struct phy *ufs_qcom_phy_generic_probe(struct platform_device *pdev,
struct ufs_qcom_phy *common_cfg,
const struct phy_ops *ufs_qcom_phy_gen_ops,
struct ufs_qcom_phy_specific_ops *phy_spec_ops);
+int ufs_qcom_phy_get_reset(struct ufs_qcom_phy *phy_common);
int ufs_qcom_phy_calibrate(struct ufs_qcom_phy *ufs_qcom_phy,
struct ufs_qcom_phy_calibration *tbl_A, int tbl_size_A,
struct ufs_qcom_phy_calibration *tbl_B, int tbl_size_B,
diff --git a/drivers/phy/qualcomm/phy-qcom-ufs-qmp-14nm.c b/drivers/phy/qualcomm/phy-qcom-ufs-qmp-14nm.c
index 1e0d4f2046a4..ef1383123883 100644
--- a/drivers/phy/qualcomm/phy-qcom-ufs-qmp-14nm.c
+++ b/drivers/phy/qualcomm/phy-qcom-ufs-qmp-14nm.c
@@ -48,6 +48,16 @@ static int ufs_qcom_phy_qmp_14nm_init(struct phy *generic_phy)
bool is_rate_B = false;
int ret;

+ ret = ufs_qcom_phy_get_reset(phy_common);
+ if (ret)
+ return ret;
+
+ if (phy_common->ufs_reset) {
+ ret = reset_control_assert(phy_common->ufs_reset);
+ if (ret)
+ return ret;
+ }
+
if (phy_common->mode == PHY_MODE_UFS_HS_B)
is_rate_B = true;

diff --git a/drivers/phy/qualcomm/phy-qcom-ufs-qmp-20nm.c b/drivers/phy/qualcomm/phy-qcom-ufs-qmp-20nm.c
index aef40f7a41d4..b05f89d734f0 100644
--- a/drivers/phy/qualcomm/phy-qcom-ufs-qmp-20nm.c
+++ b/drivers/phy/qualcomm/phy-qcom-ufs-qmp-20nm.c
@@ -67,6 +67,16 @@ static int ufs_qcom_phy_qmp_20nm_init(struct phy *generic_phy)
bool is_rate_B = false;
int ret;

+ ret = ufs_qcom_phy_get_reset(phy_common);
+ if (ret)
+ return ret;
+
+ if (phy_common->ufs_reset) {
+ ret = reset_control_assert(phy_common->ufs_reset);
+ if (ret)
+ return ret;
+ }
+
if (phy_common->mode == PHY_MODE_UFS_HS_B)
is_rate_B = true;

diff --git a/drivers/phy/qualcomm/phy-qcom-ufs.c b/drivers/phy/qualcomm/phy-qcom-ufs.c
index f2979ccad00a..9cc8aa0b7a4f 100644
--- a/drivers/phy/qualcomm/phy-qcom-ufs.c
+++ b/drivers/phy/qualcomm/phy-qcom-ufs.c
@@ -147,6 +147,22 @@ struct phy *ufs_qcom_phy_generic_probe(struct platform_device *pdev,
}
EXPORT_SYMBOL_GPL(ufs_qcom_phy_generic_probe);

+int ufs_qcom_phy_get_reset(struct ufs_qcom_phy *phy_common)
+{
+ struct reset_control *reset;
+
+ if (phy_common->ufs_reset)
+ return 0;
+
+ reset = devm_reset_control_get_exclusive_by_index(phy_common->dev, 0);
+ if (IS_ERR(reset))
+ return PTR_ERR(reset);
+
+ phy_common->ufs_reset = reset;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(ufs_qcom_phy_get_reset);
+
static int __ufs_qcom_phy_clk_get(struct device *dev,
const char *name, struct clk **clk_out, bool err_print)
{
@@ -533,6 +549,14 @@ int ufs_qcom_phy_power_on(struct phy *generic_phy)
if (phy_common->is_powered_on)
return 0;

+ if (phy_common->ufs_reset) {
+ err = reset_control_deassert(phy_common->ufs_reset);
+ if (err) {
+ dev_err(dev, "Failed to assert UFS PHY reset");
+ return err;
+ }
+ }
+
if (!phy_common->is_started) {
err = ufs_qcom_phy_start_serdes(phy_common);
if (err)
@@ -620,6 +644,9 @@ int ufs_qcom_phy_power_off(struct phy *generic_phy)

ufs_qcom_phy_disable_vreg(phy_common->dev, &phy_common->vdda_pll);
ufs_qcom_phy_disable_vreg(phy_common->dev, &phy_common->vdda_phy);
+ if (phy_common->ufs_reset)
+ reset_control_assert(phy_common->ufs_reset);
+
phy_common->is_powered_on = false;

return 0;
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index ab05ef5cfdcd..1c25b1c82314 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -261,11 +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) {
@@ -274,15 +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) {
@@ -296,7 +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;
@@ -559,9 +544,6 @@ 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;
}

--
2.20.1