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phy: ti-pipe3: fix suspend
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Relying on PM-ops for shutting down PHY clocks was a
bad idea since the users (e.g. PCIe/SATA) might not
have been suspended by then.

The main culprit for not shutting down the clocks was
the stray pm_runtime_get() call in probe.

Fix the whole thing in the right way by getting rid
of that pm_runtime_get() call from probe and
removing all PM-ops. It is the sole responsibility
of the PHY user to properly turn OFF and de-initialize
the PHY as part of its suspend routine.

As PHY core serializes init/exit we don't need
to use a spinlock in this driver. So get rid of it.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
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Roger Quadros authored and Kishon Vijay Abraham I committed Jul 15, 2015
1 parent d770e55 commit 0a0830f
Showing 1 changed file with 41 additions and 131 deletions.
172 changes: 41 additions & 131 deletions drivers/phy/phy-ti-pipe3.c
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,6 @@
#include <linux/delay.h>
#include <linux/phy/omap_control_phy.h>
#include <linux/of_platform.h>
#include <linux/spinlock.h>

#define PLL_STATUS 0x00000004
#define PLL_GO 0x00000008
Expand Down Expand Up @@ -83,10 +82,6 @@ struct ti_pipe3 {
struct clk *refclk;
struct clk *div_clk;
struct pipe3_dpll_map *dpll_map;
bool enabled;
spinlock_t lock; /* serialize clock enable/disable */
/* the below flag is needed specifically for SATA */
bool refclk_enabled;
};

static struct pipe3_dpll_map dpll_map_usb[] = {
Expand Down Expand Up @@ -137,6 +132,9 @@ static struct pipe3_dpll_params *ti_pipe3_get_dpll_params(struct ti_pipe3 *phy)
return NULL;
}

static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy);
static void ti_pipe3_disable_clocks(struct ti_pipe3 *phy);

static int ti_pipe3_power_off(struct phy *x)
{
struct ti_pipe3 *phy = phy_get_drvdata(x);
Expand Down Expand Up @@ -217,6 +215,7 @@ static int ti_pipe3_init(struct phy *x)
u32 val;
int ret = 0;

ti_pipe3_enable_clocks(phy);
/*
* Set pcie_pcs register to 0x96 for proper functioning of phy
* as recommended in AM572x TRM SPRUHZ6, section 18.5.2.2, table
Expand Down Expand Up @@ -250,33 +249,35 @@ static int ti_pipe3_exit(struct phy *x)
u32 val;
unsigned long timeout;

/* SATA DPLL can't be powered down due to Errata i783 and PCIe
* does not have internal DPLL
*/
if (of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-sata") ||
of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-pcie"))
/* SATA DPLL can't be powered down due to Errata i783 */
if (of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-sata"))
return 0;

/* Put DPLL in IDLE mode */
val = ti_pipe3_readl(phy->pll_ctrl_base, PLL_CONFIGURATION2);
val |= PLL_IDLE;
ti_pipe3_writel(phy->pll_ctrl_base, PLL_CONFIGURATION2, val);

/* wait for LDO and Oscillator to power down */
timeout = jiffies + msecs_to_jiffies(PLL_IDLE_TIME);
do {
cpu_relax();
val = ti_pipe3_readl(phy->pll_ctrl_base, PLL_STATUS);
if ((val & PLL_TICOPWDN) && (val & PLL_LDOPWDN))
break;
} while (!time_after(jiffies, timeout));
/* PCIe doesn't have internal DPLL */
if (!of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-pcie")) {
/* Put DPLL in IDLE mode */
val = ti_pipe3_readl(phy->pll_ctrl_base, PLL_CONFIGURATION2);
val |= PLL_IDLE;
ti_pipe3_writel(phy->pll_ctrl_base, PLL_CONFIGURATION2, val);

if (!(val & PLL_TICOPWDN) || !(val & PLL_LDOPWDN)) {
dev_err(phy->dev, "Failed to power down: PLL_STATUS 0x%x\n",
val);
return -EBUSY;
/* wait for LDO and Oscillator to power down */
timeout = jiffies + msecs_to_jiffies(PLL_IDLE_TIME);
do {
cpu_relax();
val = ti_pipe3_readl(phy->pll_ctrl_base, PLL_STATUS);
if ((val & PLL_TICOPWDN) && (val & PLL_LDOPWDN))
break;
} while (!time_after(jiffies, timeout));

if (!(val & PLL_TICOPWDN) || !(val & PLL_LDOPWDN)) {
dev_err(phy->dev, "Failed to power down: PLL_STATUS 0x%x\n",
val);
return -EBUSY;
}
}

ti_pipe3_disable_clocks(phy);

return 0;
}
static struct phy_ops ops = {
Expand Down Expand Up @@ -306,7 +307,6 @@ static int ti_pipe3_probe(struct platform_device *pdev)
return -ENOMEM;

phy->dev = &pdev->dev;
spin_lock_init(&phy->lock);

if (!of_device_is_compatible(node, "ti,phy-pipe3-pcie")) {
match = of_match_device(ti_pipe3_id_table, &pdev->dev);
Expand Down Expand Up @@ -402,6 +402,10 @@ static int ti_pipe3_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, phy);
pm_runtime_enable(phy->dev);
/* Prevent auto-disable of refclk for SATA PHY due to Errata i783 */
if (of_device_is_compatible(node, "ti,phy-pipe3-sata"))
if (!IS_ERR(phy->refclk))
clk_prepare_enable(phy->refclk);

generic_phy = devm_phy_create(phy->dev, NULL, &ops);
if (IS_ERR(generic_phy))
Expand All @@ -413,160 +417,67 @@ static int ti_pipe3_probe(struct platform_device *pdev)
if (IS_ERR(phy_provider))
return PTR_ERR(phy_provider);

pm_runtime_get(&pdev->dev);

return 0;
}

static int ti_pipe3_remove(struct platform_device *pdev)
{
if (!pm_runtime_suspended(&pdev->dev))
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);

return 0;
}

#ifdef CONFIG_PM
static int ti_pipe3_enable_refclk(struct ti_pipe3 *phy)
static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy)
{
if (!IS_ERR(phy->refclk) && !phy->refclk_enabled) {
int ret;
int ret = 0;

if (!IS_ERR(phy->refclk)) {
ret = clk_prepare_enable(phy->refclk);
if (ret) {
dev_err(phy->dev, "Failed to enable refclk %d\n", ret);
return ret;
}
phy->refclk_enabled = true;
}

return 0;
}

static void ti_pipe3_disable_refclk(struct ti_pipe3 *phy)
{
if (!IS_ERR(phy->refclk))
clk_disable_unprepare(phy->refclk);

phy->refclk_enabled = false;
}

static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy)
{
int ret = 0;
unsigned long flags;

spin_lock_irqsave(&phy->lock, flags);
if (phy->enabled)
goto err1;

ret = ti_pipe3_enable_refclk(phy);
if (ret)
goto err1;

if (!IS_ERR(phy->wkupclk)) {
ret = clk_prepare_enable(phy->wkupclk);
if (ret) {
dev_err(phy->dev, "Failed to enable wkupclk %d\n", ret);
goto err2;
goto disable_refclk;
}
}

if (!IS_ERR(phy->div_clk)) {
ret = clk_prepare_enable(phy->div_clk);
if (ret) {
dev_err(phy->dev, "Failed to enable div_clk %d\n", ret);
goto err3;
goto disable_wkupclk;
}
}

phy->enabled = true;
spin_unlock_irqrestore(&phy->lock, flags);
return 0;

err3:
disable_wkupclk:
if (!IS_ERR(phy->wkupclk))
clk_disable_unprepare(phy->wkupclk);

err2:
disable_refclk:
if (!IS_ERR(phy->refclk))
clk_disable_unprepare(phy->refclk);

ti_pipe3_disable_refclk(phy);
err1:
spin_unlock_irqrestore(&phy->lock, flags);
return ret;
}

static void ti_pipe3_disable_clocks(struct ti_pipe3 *phy)
{
unsigned long flags;

spin_lock_irqsave(&phy->lock, flags);
if (!phy->enabled) {
spin_unlock_irqrestore(&phy->lock, flags);
return;
}

if (!IS_ERR(phy->wkupclk))
clk_disable_unprepare(phy->wkupclk);
/* Don't disable refclk for SATA PHY due to Errata i783 */
if (!of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-sata"))
ti_pipe3_disable_refclk(phy);
if (!IS_ERR(phy->refclk))
clk_disable_unprepare(phy->refclk);
if (!IS_ERR(phy->div_clk))
clk_disable_unprepare(phy->div_clk);
phy->enabled = false;
spin_unlock_irqrestore(&phy->lock, flags);
}

static int ti_pipe3_runtime_suspend(struct device *dev)
{
struct ti_pipe3 *phy = dev_get_drvdata(dev);

ti_pipe3_disable_clocks(phy);
return 0;
}

static int ti_pipe3_runtime_resume(struct device *dev)
{
struct ti_pipe3 *phy = dev_get_drvdata(dev);
int ret = 0;

ret = ti_pipe3_enable_clocks(phy);
return ret;
}

static int ti_pipe3_suspend(struct device *dev)
{
struct ti_pipe3 *phy = dev_get_drvdata(dev);

ti_pipe3_disable_clocks(phy);
return 0;
}

static int ti_pipe3_resume(struct device *dev)
{
struct ti_pipe3 *phy = dev_get_drvdata(dev);
int ret;

ret = ti_pipe3_enable_clocks(phy);
if (ret)
return ret;

pm_runtime_disable(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
return 0;
}
#endif

static const struct dev_pm_ops ti_pipe3_pm_ops = {
SET_RUNTIME_PM_OPS(ti_pipe3_runtime_suspend,
ti_pipe3_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(ti_pipe3_suspend, ti_pipe3_resume)
};

static const struct of_device_id ti_pipe3_id_table[] = {
{
.compatible = "ti,phy-usb3",
Expand All @@ -592,7 +503,6 @@ static struct platform_driver ti_pipe3_driver = {
.remove = ti_pipe3_remove,
.driver = {
.name = "ti-pipe3",
.pm = &ti_pipe3_pm_ops,
.of_match_table = ti_pipe3_id_table,
},
};
Expand Down

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