[PATCH v4] phy: zynqmp: Handle the clock enable/disable properly

From: Manish Narani
Date: Wed Mar 24 2021 - 08:19:56 EST


The current driver is not handling the clock enable/disable operations
properly. The clocks need to be handled correctly by enabling or
disabling at appropriate places. This patch adds code to handle the
same.

Signed-off-by: Manish Narani <manish.narani@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
drivers/phy/xilinx/phy-zynqmp.c | 58 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 51 insertions(+), 7 deletions(-)

diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
index 2b65f84..3565215 100644
--- a/drivers/phy/xilinx/phy-zynqmp.c
+++ b/drivers/phy/xilinx/phy-zynqmp.c
@@ -208,6 +208,7 @@ struct xpsgtr_phy {
* @gtr_mutex: mutex for locking
* @phys: PHY lanes
* @refclk_sscs: spread spectrum settings for the reference clocks
+ * @clk: reference clocks
* @tx_term_fix: fix for GT issue
* @saved_icm_cfg0: stored value of ICM CFG0 register
* @saved_icm_cfg1: stored value of ICM CFG1 register
@@ -219,6 +220,7 @@ struct xpsgtr_dev {
struct mutex gtr_mutex; /* mutex for locking */
struct xpsgtr_phy phys[NUM_LANES];
const struct xpsgtr_ssc *refclk_sscs[NUM_LANES];
+ struct clk *clk[NUM_LANES];
bool tx_term_fix;
unsigned int saved_icm_cfg0;
unsigned int saved_icm_cfg1;
@@ -818,11 +820,15 @@ static struct phy *xpsgtr_xlate(struct device *dev,
static int __maybe_unused xpsgtr_suspend(struct device *dev)
{
struct xpsgtr_dev *gtr_dev = dev_get_drvdata(dev);
+ unsigned int i;

/* Save the snapshot ICM_CFG registers. */
gtr_dev->saved_icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
gtr_dev->saved_icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);

+ for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++)
+ clk_disable_unprepare(gtr_dev->clk[i]);
+
return 0;
}

@@ -832,6 +838,13 @@ static int __maybe_unused xpsgtr_resume(struct device *dev)
unsigned int icm_cfg0, icm_cfg1;
unsigned int i;
bool skip_phy_init;
+ int err;
+
+ for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++) {
+ err = clk_prepare_enable(gtr_dev->clk[i]);
+ if (err)
+ goto err_clk_put;
+ }

icm_cfg0 = xpsgtr_read(gtr_dev, ICM_CFG0);
icm_cfg1 = xpsgtr_read(gtr_dev, ICM_CFG1);
@@ -852,6 +865,12 @@ static int __maybe_unused xpsgtr_resume(struct device *dev)
gtr_dev->phys[i].skip_phy_init = skip_phy_init;

return 0;
+
+err_clk_put:
+ while (i--)
+ clk_disable_unprepare(gtr_dev->clk[i]);
+
+ return err;
}

static const struct dev_pm_ops xpsgtr_pm_ops = {
@@ -865,6 +884,7 @@ static const struct dev_pm_ops xpsgtr_pm_ops = {
static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
{
unsigned int refclk;
+ int ret;

for (refclk = 0; refclk < ARRAY_SIZE(gtr_dev->refclk_sscs); ++refclk) {
unsigned long rate;
@@ -874,14 +894,22 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)

snprintf(name, sizeof(name), "ref%u", refclk);
clk = devm_clk_get_optional(gtr_dev->dev, name);
- if (IS_ERR(clk))
- return dev_err_probe(gtr_dev->dev, PTR_ERR(clk),
- "Failed to get reference clock %u\n",
- refclk);
+ if (IS_ERR(clk)) {
+ ret = dev_err_probe(gtr_dev->dev, PTR_ERR(clk),
+ "Failed to get reference clock %u\n",
+ refclk);
+ goto err_clk_put;
+ }

if (!clk)
continue;

+ ret = clk_prepare_enable(clk);
+ if (ret)
+ goto err_clk_put;
+
+ gtr_dev->clk[refclk] = clk;
+
/*
* Get the spread spectrum (SSC) settings for the reference
* clock rate.
@@ -899,11 +927,18 @@ static int xpsgtr_get_ref_clocks(struct xpsgtr_dev *gtr_dev)
dev_err(gtr_dev->dev,
"Invalid rate %lu for reference clock %u\n",
rate, refclk);
- return -EINVAL;
+ ret = -EINVAL;
+ goto err_clk_put;
}
}

return 0;
+
+err_clk_put:
+ while (refclk--)
+ clk_disable_unprepare(gtr_dev->clk[refclk]);
+
+ return ret;
}

static int xpsgtr_probe(struct platform_device *pdev)
@@ -912,6 +947,7 @@ static int xpsgtr_probe(struct platform_device *pdev)
struct xpsgtr_dev *gtr_dev;
struct phy_provider *provider;
unsigned int port;
+ unsigned int i;
int ret;

gtr_dev = devm_kzalloc(&pdev->dev, sizeof(*gtr_dev), GFP_KERNEL);
@@ -951,7 +987,8 @@ static int xpsgtr_probe(struct platform_device *pdev)
phy = devm_phy_create(&pdev->dev, np, &xpsgtr_phyops);
if (IS_ERR(phy)) {
dev_err(&pdev->dev, "failed to create PHY\n");
- return PTR_ERR(phy);
+ ret = PTR_ERR(phy);
+ goto err_clk_put;
}

gtr_phy->phy = phy;
@@ -962,9 +999,16 @@ static int xpsgtr_probe(struct platform_device *pdev)
provider = devm_of_phy_provider_register(&pdev->dev, xpsgtr_xlate);
if (IS_ERR(provider)) {
dev_err(&pdev->dev, "registering provider failed\n");
- return PTR_ERR(provider);
+ ret = PTR_ERR(provider);
+ goto err_clk_put;
}
return 0;
+
+err_clk_put:
+ for (i = 0; i < ARRAY_SIZE(gtr_dev->clk); i++)
+ clk_disable_unprepare(gtr_dev->clk[i]);
+
+ return ret;
}

static const struct of_device_id xpsgtr_of_match[] = {
--
2.1.1