From: Gilad Broner <gbro...@codeaurora.org>

Different platforms may have different number of lanes for the UFS Tx/Rx
links. Add parameter to device tree specifying how many lanes should be
configured for the UFS Tx/Rx links. And don't print err message for clocks
that are optional, this leads to unnecessary confusion about failure.

Signed-off-by: Gilad Broner <gbro...@codeaurora.org>
Signed-off-by: Subhash Jadavani <subha...@codeaurora.org>
Signed-off-by: Can Guo <c...@codeaurora.org>
---

Changes since v1:
        - Change commit subject for better description.
        - Incorporated Rob's review comments to use lanes-tx and lanes-rx
          to handle asymmetric Tx/Rx links.

 .../devicetree/bindings/ufs/ufshcd-pltfrm.txt      |  4 ++
 drivers/scsi/ufs/ufs-qcom.c                        | 65 +++++++++++++---------
 drivers/scsi/ufs/ufshcd.c                          | 29 ++++++++++
 drivers/scsi/ufs/ufshcd.h                          |  5 ++
 4 files changed, 78 insertions(+), 25 deletions(-)

diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt 
b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
index 5357919..257308e 100644
--- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
+++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
@@ -31,6 +31,10 @@ Optional properties:
                          defined or a value in the array is "0" then it is 
assumed
                          that the frequency is set by the parent clock or a
                          fixed rate clock source.
+- lanes-tx             : Number of lanes available for Tx direction - either 1 
or 2.
+                         If not specified, default is 2 lanes.
+- lanes-rx             : Number of lanes available for Rx direction - either 1 
or 2.
+                         If not specified, default is 2 lanes.
 
 Note: If above properties are not defined it can be assumed that the supply
 regulators or clocks are always on.
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 4cdffa4..154e7f1 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -50,13 +50,10 @@ static int ufs_qcom_host_clk_get(struct device *dev,
        int err = 0;
 
        clk = devm_clk_get(dev, name);
-       if (IS_ERR(clk)) {
+       if (IS_ERR(clk))
                err = PTR_ERR(clk);
-               dev_err(dev, "%s: failed to get %s err %d",
-                               __func__, name, err);
-       } else {
+       else
                *clk_out = clk;
-       }
 
        return err;
 }
@@ -78,9 +75,11 @@ static void ufs_qcom_disable_lane_clks(struct ufs_qcom_host 
*host)
        if (!host->is_lane_clks_enabled)
                return;
 
-       clk_disable_unprepare(host->tx_l1_sync_clk);
+       if (host->tx_l1_sync_clk)
+               clk_disable_unprepare(host->tx_l1_sync_clk);
        clk_disable_unprepare(host->tx_l0_sync_clk);
-       clk_disable_unprepare(host->rx_l1_sync_clk);
+       if (host->rx_l1_sync_clk)
+               clk_disable_unprepare(host->rx_l1_sync_clk);
        clk_disable_unprepare(host->rx_l0_sync_clk);
 
        host->is_lane_clks_enabled = false;
@@ -104,21 +103,23 @@ static int ufs_qcom_enable_lane_clks(struct ufs_qcom_host 
*host)
        if (err)
                goto disable_rx_l0;
 
-       err = ufs_qcom_host_clk_enable(dev, "rx_lane1_sync_clk",
-               host->rx_l1_sync_clk);
-       if (err)
-               goto disable_tx_l0;
+       if (host->hba->lanes_rx > 1) {
+               err = ufs_qcom_host_clk_enable(dev, "rx_lane1_sync_clk",
+                       host->rx_l1_sync_clk);
+               if (err)
+                       goto disable_tx_l0;
+       }
 
-       err = ufs_qcom_host_clk_enable(dev, "tx_lane1_sync_clk",
-               host->tx_l1_sync_clk);
-       if (err)
-               goto disable_rx_l1;
+       if (host->hba->lanes_tx > 1) {
+               /* The tx lane1 clk could be muxed, hence keep this optional */
+               if (host->tx_l1_sync_clk)
+                       ufs_qcom_host_clk_enable(dev, "tx_lane1_sync_clk",
+                                                host->tx_l1_sync_clk);
+       }
 
        host->is_lane_clks_enabled = true;
        goto out;
 
-disable_rx_l1:
-       clk_disable_unprepare(host->rx_l1_sync_clk);
 disable_tx_l0:
        clk_disable_unprepare(host->tx_l0_sync_clk);
 disable_rx_l0:
@@ -134,21 +135,35 @@ static int ufs_qcom_init_lane_clks(struct ufs_qcom_host 
*host)
 
        err = ufs_qcom_host_clk_get(dev,
                        "rx_lane0_sync_clk", &host->rx_l0_sync_clk);
-       if (err)
+       if (err) {
+               dev_err(dev, "%s: failed to get rx_lane0_sync_clk, err %d",
+                               __func__, err);
                goto out;
+       }
 
        err = ufs_qcom_host_clk_get(dev,
                        "tx_lane0_sync_clk", &host->tx_l0_sync_clk);
-       if (err)
+       if (err) {
+               dev_err(dev, "%s: failed to get tx_lane0_sync_clk, err %d",
+                               __func__, err);
                goto out;
+       }
 
-       err = ufs_qcom_host_clk_get(dev, "rx_lane1_sync_clk",
-               &host->rx_l1_sync_clk);
-       if (err)
-               goto out;
+       if (host->hba->lanes_rx > 1) {
+               err = ufs_qcom_host_clk_get(dev, "rx_lane1_sync_clk",
+                       &host->rx_l1_sync_clk);
+               if (err) {
+                       dev_err(dev, "%s: failed to get rx_lane1_sync_clk, err 
%d",
+                                       __func__, err);
+                       goto out;
+               }
+       }
 
-       err = ufs_qcom_host_clk_get(dev, "tx_lane1_sync_clk",
-               &host->tx_l1_sync_clk);
+       if (host->hba->lanes_tx > 1) {
+               /* The tx lane1 clk could be muxed, hence keep this optional */
+               ufs_qcom_host_clk_get(dev, "tx_lane1_sync_clk",
+                                       &host->tx_l1_sync_clk);
+       }
 out:
        return err;
 }
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index b0ade73..307d0070 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -39,6 +39,7 @@
 
 #include <linux/async.h>
 #include <linux/devfreq.h>
+#include <linux/of.h>
 
 #include "ufshcd.h"
 #include "unipro.h"
@@ -74,6 +75,8 @@
 /* Interrupt aggregation default timeout, unit: 40us */
 #define INT_AGGR_DEF_TO        0x02
 
+#define UFSHCD_DEFAULT_LANES_PER_DIRECTION             2
+
 #define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
        ({                                                              \
                int _ret;                                               \
@@ -5530,6 +5533,30 @@ static struct devfreq_dev_profile ufs_devfreq_profile = {
        .get_dev_status = ufshcd_devfreq_get_dev_status,
 };
 
+static void ufshcd_init_lanes_per_dir(struct ufs_hba *hba)
+{
+       struct device *dev = hba->dev;
+       int ret;
+
+       ret = of_property_read_u32(dev->of_node, "lanes-tx",
+               &hba->lanes_tx);
+       if (ret) {
+               dev_dbg(hba->dev,
+                       "%s: failed to read lanes-tx, ret=%d\n",
+                       __func__, ret);
+               hba->lanes_tx = UFSHCD_DEFAULT_LANES_PER_DIRECTION;
+       }
+
+       ret = of_property_read_u32(dev->of_node, "lanes-rx",
+               &hba->lanes_rx);
+       if (ret) {
+               dev_dbg(hba->dev,
+                       "%s: failed to read lanes-rx, ret=%d\n",
+                       __func__, ret);
+               hba->lanes_rx = UFSHCD_DEFAULT_LANES_PER_DIRECTION;
+       }
+}
+
 /**
  * ufshcd_init - Driver initialization routine
  * @hba: per-adapter instance
@@ -5553,6 +5580,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem 
*mmio_base, unsigned int irq)
        hba->mmio_base = mmio_base;
        hba->irq = irq;
 
+       ufshcd_init_lanes_per_dir(hba);
+
        err = ufshcd_hba_init(hba);
        if (err)
                goto out_error;
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index c40a0e7..b3b8abe 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -500,6 +500,11 @@ struct ufs_hba {
 
        bool wlun_dev_clr_ua;
 
+       /* Number of lanes available (1 or 2) for Tx */
+       u32 lanes_tx;
+       /* Number of lanes available (1 or 2) for Rx */
+       u32 lanes_rx;
+
        struct ufs_pa_layer_attr pwr_info;
        struct ufs_pwr_mode_info max_pwr_info;
 
-- 
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