From: Dov Levenglick <d...@codeaurora.org>

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 <d...@codeaurora.org>
Signed-off-by: Amit Nischal <anisc...@codeaurora.org>
Signed-off-by: Subhash Jadavani <subha...@codeaurora.org>
Signed-off-by: Can Guo <c...@codeaurora.org>
---
 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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