scsi: ufs-qcom: add number of lanes per direction

Different platform may have different number of lanes
for the UFS link.
Add parameter to device tree specifying how many lanes
should be configured for the UFS link.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
index 03c0e989e020a98ec28195896c8f8612686a580e..66f6adf8d44da55c87cb1fdd5ef501e40c3ea273 100644 (file)
--- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
+++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
@@ -38,6 +38,9 @@ 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-per-direction   : number of lanes available per direction - either 1 or 2.
+                         Note that it is assume same number of lanes is used both
+                         directions at once. If not specified, default is 2 lanes per direction.
 
 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 4f38d008bfb401d9eeeb359472e643bdf3e85c9b..ed5772902f4b00da6b46c2d709ccf8b87f410eb7 100644 (file)
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Linux Foundation. All rights reserved.
+ * Copyright (c) 2013-2016, Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -132,21 +132,24 @@ 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_per_direction > 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;
+               err = ufs_qcom_host_clk_enable(dev, "tx_lane1_sync_clk",
+                       host->tx_l1_sync_clk);
+               if (err)
+                       goto disable_rx_l1;
+       }
 
        host->is_lane_clks_enabled = true;
        goto out;
 
 disable_rx_l1:
-       clk_disable_unprepare(host->rx_l1_sync_clk);
+       if (host->hba->lanes_per_direction > 1)
+               clk_disable_unprepare(host->rx_l1_sync_clk);
 disable_tx_l0:
        clk_disable_unprepare(host->tx_l0_sync_clk);
 disable_rx_l0:
@@ -170,14 +173,16 @@ static int ufs_qcom_init_lane_clks(struct ufs_qcom_host *host)
        if (err)
                goto out;
 
-       err = ufs_qcom_host_clk_get(dev, "rx_lane1_sync_clk",
-               &host->rx_l1_sync_clk);
-       if (err)
-               goto out;
-
-       err = ufs_qcom_host_clk_get(dev, "tx_lane1_sync_clk",
-               &host->tx_l1_sync_clk);
+       /* In case of single lane per direction, don't read lane1 clocks */
+       if (host->hba->lanes_per_direction > 1) {
+               err = ufs_qcom_host_clk_get(dev, "rx_lane1_sync_clk",
+                       &host->rx_l1_sync_clk);
+               if (err)
+                       goto out;
 
+               err = 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-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
index d2a7b127b05c19e259c5dca4a4771bdfdb97b5f5..718f12e0988535fa14b517c1288626fa5d5da99f 100644 (file)
--- a/drivers/scsi/ufs/ufshcd-pltfrm.c
+++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
@@ -40,6 +40,8 @@
 #include "ufshcd.h"
 #include "ufshcd-pltfrm.h"
 
+#define UFSHCD_DEFAULT_LANES_PER_DIRECTION             2
+
 static int ufshcd_parse_clock_info(struct ufs_hba *hba)
 {
        int ret = 0;
@@ -277,6 +279,21 @@ void ufshcd_pltfrm_shutdown(struct platform_device *pdev)
 }
 EXPORT_SYMBOL_GPL(ufshcd_pltfrm_shutdown);
 
+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-per-direction",
+               &hba->lanes_per_direction);
+       if (ret) {
+               dev_dbg(hba->dev,
+                       "%s: failed to read lanes-per-direction, ret=%d\n",
+                       __func__, ret);
+               hba->lanes_per_direction = UFSHCD_DEFAULT_LANES_PER_DIRECTION;
+       }
+}
+
 /**
  * ufshcd_pltfrm_init - probe routine of the driver
  * @pdev: pointer to Platform device handle
@@ -331,6 +348,8 @@ int ufshcd_pltfrm_init(struct platform_device *pdev,
        pm_runtime_set_active(&pdev->dev);
        pm_runtime_enable(&pdev->dev);
 
+       ufshcd_init_lanes_per_dir(hba);
+
        err = ufshcd_init(hba, mmio_base, irq);
        if (err) {
                dev_err(dev, "Initialization failed\n");

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 9c1b94bef8f344ce722406d179c8b0f172001bd6..a8e42dfc32ecd9d493522f4e7d8fe8ce1ccae671 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -40,6 +40,7 @@
 #include <linux/async.h>
 #include <linux/devfreq.h>
 
+#include <linux/of.h>
 #include "ufshcd.h"
 #include "unipro.h"
 

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index e3931d0c94eb9e63c3c5fbe5158e631e7133ac3c..9ae7f85b2a3346de0a69990cb0bd58df0556a09e 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -509,6 +509,8 @@ struct ufs_hba {
 
        bool wlun_dev_clr_ua;
 
+       /* Number of lanes available (1 or 2) for Rx/Tx */
+       u32 lanes_per_direction;
        struct ufs_pa_layer_attr pwr_info;
        struct ufs_pwr_mode_info max_pwr_info;