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path: root/drivers/pwm/pwm-tiehrpwm.c
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Diffstat (limited to 'drivers/pwm/pwm-tiehrpwm.c')
-rw-r--r--drivers/pwm/pwm-tiehrpwm.c177
1 files changed, 162 insertions, 15 deletions
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index d3c1dff0a0d..cb75133085a 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -25,6 +25,9 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/pm_runtime.h>
+#include <linux/of_device.h>
+
+#include "pwm-tipwmss.h"
/* EHRPWM registers and bits definitions */
@@ -109,12 +112,25 @@
#define NUM_PWM_CHANNEL 2 /* EHRPWM channels */
+struct ehrpwm_context {
+ u16 tbctl;
+ u16 tbprd;
+ u16 cmpa;
+ u16 cmpb;
+ u16 aqctla;
+ u16 aqctlb;
+ u16 aqsfrc;
+ u16 aqcsfrc;
+};
+
struct ehrpwm_pwm_chip {
struct pwm_chip chip;
unsigned int clk_rate;
void __iomem *mmio_base;
unsigned long period_cycles[NUM_PWM_CHANNEL];
enum pwm_polarity polarity[NUM_PWM_CHANNEL];
+ struct clk *tbclk;
+ struct ehrpwm_context ctx;
};
static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
@@ -122,12 +138,17 @@ static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
return container_of(chip, struct ehrpwm_pwm_chip, chip);
}
-static void ehrpwm_write(void *base, int offset, unsigned int val)
+static inline u16 ehrpwm_read(void __iomem *base, int offset)
+{
+ return readw(base + offset);
+}
+
+static inline void ehrpwm_write(void __iomem *base, int offset, unsigned int val)
{
writew(val & 0xFFFF, base + offset);
}
-static void ehrpwm_modify(void *base, int offset,
+static void ehrpwm_modify(void __iomem *base, int offset,
unsigned short mask, unsigned short val)
{
unsigned short regval;
@@ -313,6 +334,7 @@ static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
unsigned short aqcsfrc_val, aqcsfrc_mask;
+ int ret;
/* Leave clock enabled on enabling PWM */
pm_runtime_get_sync(chip->dev);
@@ -335,6 +357,14 @@ static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
/* Channels polarity can be configured from action qualifier module */
configure_polarity(pc, pwm->hwpwm);
+ /* Enable TBCLK before enabling PWM device */
+ ret = clk_enable(pc->tbclk);
+ if (ret) {
+ dev_err(chip->dev, "Failed to enable TBCLK for %s\n",
+ dev_name(pc->chip.dev));
+ return ret;
+ }
+
/* Enable time counter for free_run */
ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
return 0;
@@ -363,6 +393,9 @@ static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
+ /* Disabling TBCLK on PWM disable */
+ clk_disable(pc->tbclk);
+
/* Stop Time base counter */
ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
@@ -392,18 +425,23 @@ static const struct pwm_ops ehrpwm_pwm_ops = {
.owner = THIS_MODULE,
};
-static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
+static const struct of_device_id ehrpwm_of_match[] = {
+ { .compatible = "ti,am33xx-ehrpwm" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
+
+static int ehrpwm_pwm_probe(struct platform_device *pdev)
{
int ret;
struct resource *r;
struct clk *clk;
struct ehrpwm_pwm_chip *pc;
+ u16 status;
pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
- if (!pc) {
- dev_err(&pdev->dev, "failed to allocate memory\n");
+ if (!pc)
return -ENOMEM;
- }
clk = devm_clk_get(&pdev->dev, "fck");
if (IS_ERR(clk)) {
@@ -419,18 +457,28 @@ static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
pc->chip.dev = &pdev->dev;
pc->chip.ops = &ehrpwm_pwm_ops;
+ pc->chip.of_xlate = of_pwm_xlate_with_flags;
+ pc->chip.of_pwm_n_cells = 3;
pc->chip.base = -1;
pc->chip.npwm = NUM_PWM_CHANNEL;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!r) {
- dev_err(&pdev->dev, "no memory resource defined\n");
- return -ENODEV;
+ pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(pc->mmio_base))
+ return PTR_ERR(pc->mmio_base);
+
+ /* Acquire tbclk for Time Base EHRPWM submodule */
+ pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
+ if (IS_ERR(pc->tbclk)) {
+ dev_err(&pdev->dev, "Failed to get tbclk\n");
+ return PTR_ERR(pc->tbclk);
}
- pc->mmio_base = devm_request_and_ioremap(&pdev->dev, r);
- if (!pc->mmio_base)
- return -EADDRNOTAVAIL;
+ ret = clk_prepare(pc->tbclk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
+ return ret;
+ }
ret = pwmchip_add(&pc->chip);
if (ret < 0) {
@@ -439,25 +487,124 @@ static int __devinit ehrpwm_pwm_probe(struct platform_device *pdev)
}
pm_runtime_enable(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
+
+ status = pwmss_submodule_state_change(pdev->dev.parent,
+ PWMSS_EPWMCLK_EN);
+ if (!(status & PWMSS_EPWMCLK_EN_ACK)) {
+ dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
+ ret = -EINVAL;
+ goto pwmss_clk_failure;
+ }
+
+ pm_runtime_put_sync(&pdev->dev);
+
platform_set_drvdata(pdev, pc);
return 0;
+
+pwmss_clk_failure:
+ pm_runtime_put_sync(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+ pwmchip_remove(&pc->chip);
+ clk_unprepare(pc->tbclk);
+ return ret;
}
-static int __devexit ehrpwm_pwm_remove(struct platform_device *pdev)
+static int ehrpwm_pwm_remove(struct platform_device *pdev)
{
struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
+ clk_unprepare(pc->tbclk);
+
+ pm_runtime_get_sync(&pdev->dev);
+ /*
+ * Due to hardware misbehaviour, acknowledge of the stop_req
+ * is missing. Hence checking of the status bit skipped.
+ */
+ pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ);
+ pm_runtime_put_sync(&pdev->dev);
+
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return pwmchip_remove(&pc->chip);
}
+#ifdef CONFIG_PM_SLEEP
+static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
+{
+ pm_runtime_get_sync(pc->chip.dev);
+ pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
+ pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
+ pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
+ pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
+ pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
+ pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
+ pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
+ pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
+ pm_runtime_put_sync(pc->chip.dev);
+}
+
+static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
+{
+ ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
+ ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
+ ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
+ ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
+ ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
+ ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
+ ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
+ ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
+}
+
+static int ehrpwm_pwm_suspend(struct device *dev)
+{
+ struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
+ int i;
+
+ ehrpwm_pwm_save_context(pc);
+ for (i = 0; i < pc->chip.npwm; i++) {
+ struct pwm_device *pwm = &pc->chip.pwms[i];
+
+ if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ continue;
+
+ /* Disable explicitly if PWM is running */
+ pm_runtime_put_sync(dev);
+ }
+ return 0;
+}
+
+static int ehrpwm_pwm_resume(struct device *dev)
+{
+ struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < pc->chip.npwm; i++) {
+ struct pwm_device *pwm = &pc->chip.pwms[i];
+
+ if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ continue;
+
+ /* Enable explicitly if PWM was running */
+ pm_runtime_get_sync(dev);
+ }
+ ehrpwm_pwm_restore_context(pc);
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
+ ehrpwm_pwm_resume);
+
static struct platform_driver ehrpwm_pwm_driver = {
.driver = {
- .name = "ehrpwm",
+ .name = "ehrpwm",
+ .owner = THIS_MODULE,
+ .of_match_table = ehrpwm_of_match,
+ .pm = &ehrpwm_pwm_pm_ops,
},
.probe = ehrpwm_pwm_probe,
- .remove = __devexit_p(ehrpwm_pwm_remove),
+ .remove = ehrpwm_pwm_remove,
};
module_platform_driver(ehrpwm_pwm_driver);