[PATCH v2] scsi: ufs-qcom: add number of lanes for Tx and Rx links

From: Can Guo
Date: Tue Feb 27 2018 - 00:55:25 EST


From: Gilad Broner <gbroner@xxxxxxxxxxxxxx>

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 <gbroner@xxxxxxxxxxxxxx>
Signed-off-by: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
---

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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