[PATCH v10 4/6] scsi: ufs: Add core reset support

From: Can Guo
Date: Tue Oct 23 2018 - 00:36:29 EST


From: Dov Levenglick <dovl@xxxxxxxxxxxxxx>

Enables core reset support. Add full initialization of the PHY and the
controller before initializing UFS PHY and during link recovery.

Signed-off-by: Dov Levenglick <dovl@xxxxxxxxxxxxxx>
Signed-off-by: Amit Nischal <anischal@xxxxxxxxxxxxxx>
Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufs-qcom.c | 30 ++++++++++++++++++++++++++++++
drivers/scsi/ufs/ufshcd-pltfrm.c | 22 ++++++++++++++++++++++
drivers/scsi/ufs/ufshcd.c | 13 +++++++++++++
drivers/scsi/ufs/ufshcd.h | 12 ++++++++++++
4 files changed, 77 insertions(+)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2b38db2..698b92d 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -616,6 +616,35 @@ static int ufs_qcom_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
return err;
}

+static int ufs_qcom_core_reset(struct ufs_hba *hba)
+{
+ int ret = -ENOTSUPP;
+
+ if (!hba->core_reset) {
+ dev_err(hba->dev, "%s: failed, err = %d\n", __func__,
+ ret);
+ goto out;
+ }
+
+ ret = reset_control_assert(hba->core_reset);
+ if (ret) {
+ dev_err(hba->dev, "core_reset assert failed, err = %d\n",
+ ret);
+ goto out;
+ }
+
+ /* As per spec, delay is required to let reset assert go through */
+ usleep_range(1, 2);
+
+ ret = reset_control_deassert(hba->core_reset);
+ if (ret)
+ dev_err(hba->dev, "core_reset deassert failed, err = %d\n",
+ ret);
+
+out:
+ return ret;
+}
+
struct ufs_qcom_dev_params {
u32 pwm_rx_gear; /* pwm rx gear to work in */
u32 pwm_tx_gear; /* pwm tx gear to work in */
@@ -1670,6 +1699,7 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
.apply_dev_quirks = ufs_qcom_apply_dev_quirks,
.suspend = ufs_qcom_suspend,
.resume = ufs_qcom_resume,
+ .core_reset = ufs_qcom_core_reset,
.dbg_register_dump = ufs_qcom_dump_dbg_regs,
};

diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index e82bde0..dab11a7 100644
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -42,6 +42,22 @@

#define UFSHCD_DEFAULT_LANES_PER_DIRECTION 2

+static int ufshcd_parse_reset_info(struct ufs_hba *hba)
+{
+ int ret = 0;
+
+ hba->core_reset = devm_reset_control_get_optional_exclusive(hba->dev,
+ "rst");
+ if (IS_ERR(hba->core_reset)) {
+ ret = PTR_ERR(hba->core_reset);
+ dev_err(hba->dev, "core_reset unavailable,err = %d\n",
+ ret);
+ hba->core_reset = NULL;
+ }
+
+ return ret;
+}
+
static int ufshcd_parse_clock_info(struct ufs_hba *hba)
{
int ret = 0;
@@ -340,6 +356,12 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
goto dealloc_host;
}

+ err = ufshcd_parse_reset_info(hba);
+ if (err) {
+ dev_err(&pdev->dev, "%s: reset parse failed %d\n",
+ __func__, err);
+ }
+
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index a355d98..d18c3af 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3657,6 +3657,15 @@ static int ufshcd_link_recovery(struct ufs_hba *hba)
ufshcd_set_eh_in_progress(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);

+ if (hba->core_reset) {
+ ret = ufshcd_vops_core_reset(hba);
+ if (ret)
+ dev_err(hba->dev,
+ "full reset returned %d, trying to recover the link\n",
+ ret);
+ return ret;
+ }
+
ret = ufshcd_host_reset_and_restore(hba);

spin_lock_irqsave(hba->host->host_lock, flags);
@@ -7948,6 +7957,10 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
goto exit_gating;
}

+ /* Reset controller to power on reset (POR) state */
+ if (hba->core_reset)
+ ufshcd_vops_core_reset(hba);
+
/* Host controller enable */
err = ufshcd_hba_enable(hba);
if (err) {
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 1332e54..aa046a1 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -55,6 +55,7 @@
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
#include "unipro.h"

#include <asm/irq.h>
@@ -295,6 +296,8 @@ struct ufs_pwr_mode_info {
* @apply_dev_quirks: called to apply device specific quirks
* @suspend: called during host controller PM callback
* @resume: called during host controller PM callback
+ * @core_reset: called before UFS PHY init and during link recovery for
+ * handling variant specific implementations of resetting the hci
* @dbg_register_dump: used to dump controller debug information
* @phy_initialization: used to initialize phys
*/
@@ -323,6 +326,7 @@ struct ufs_hba_variant_ops {
int (*apply_dev_quirks)(struct ufs_hba *);
int (*suspend)(struct ufs_hba *, enum ufs_pm_op);
int (*resume)(struct ufs_hba *, enum ufs_pm_op);
+ int (*core_reset)(struct ufs_hba *);
void (*dbg_register_dump)(struct ufs_hba *hba);
int (*phy_initialization)(struct ufs_hba *);
};
@@ -678,6 +682,7 @@ struct ufs_hba {
bool is_urgent_bkops_lvl_checked;

struct rw_semaphore clk_scaling_lock;
+ struct reset_control *core_reset;
struct ufs_desc_size desc_size;
};

@@ -979,6 +984,13 @@ static inline int ufshcd_vops_resume(struct ufs_hba *hba, enum ufs_pm_op op)
return 0;
}

+static inline int ufshcd_vops_core_reset(struct ufs_hba *hba)
+{
+ if (hba->vops && hba->vops->core_reset)
+ return hba->vops->core_reset(hba);
+ return 0;
+}
+
static inline void ufshcd_vops_dbg_register_dump(struct ufs_hba *hba)
{
if (hba->vops && hba->vops->dbg_register_dump)
--
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