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authorLinus Torvalds <torvalds@linux-foundation.org>2017-05-10 01:34:20 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-10 01:34:20 +0300
commitecc721a72c121e8b641d68efd24a225abedb9a30 (patch)
tree15d514f0c374292218a52dcc24a82d7c55bcfcfc /drivers/pwm/pwm-atmel.c
parent28b47809b2171a6cfbab839936b24280639c9f85 (diff)
parent97512ceafaacf8cdb96d6a36ae55e8335c0a9e55 (diff)
downloadlinux-ecc721a72c121e8b641d68efd24a225abedb9a30.tar.xz
Merge tag 'pwm/for-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding: "Adds a new driver for the PWM controller found on MediaTek SoCs and extends support for the Atmel PWM controller to include the SAMA5D2. Some existing drivers have been migrated to the atomic API and a few others see miscellaneous improvements" * tag 'pwm/for-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: tegra: Read PWM clock source rate in driver init pwm: pca9685: Fix GPIO-only operation pwm: mediatek: Don't explicitly set .owner pwm: tegra: Avoid potential overflow for short periods pwm: tegra: Add support to configure pin state in suspends/resume pwm: tegra: Add DT binding details to configure pin in suspends/resume pwm: tegra: Increase precision in PWM rate calculation pwm: tegra: Use DIV_ROUND_CLOSEST_ULL() instead of local implementation pwm: Add MediaTek PWM support dt-bindings: pwm: Add MediaTek PWM bindings pwm: atmel: Enable PWM on sama5d2 pwm: atmel: Switch to atomic PWM pwm: atmel-hlcdc: Implement the suspend/resume hooks pwm: atmel-hlcdc: Convert to the atomic PWM API
Diffstat (limited to 'drivers/pwm/pwm-atmel.c')
-rw-r--r--drivers/pwm/pwm-atmel.c276
1 files changed, 132 insertions, 144 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 67a7023be5c2..530d7dc5f1b5 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -58,17 +58,22 @@
#define PWM_MAX_PRD 0xFFFF
#define PRD_MAX_PRES 10
+struct atmel_pwm_registers {
+ u8 period;
+ u8 period_upd;
+ u8 duty;
+ u8 duty_upd;
+};
+
struct atmel_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
void __iomem *base;
+ const struct atmel_pwm_registers *regs;
unsigned int updated_pwms;
/* ISR is cleared when read, ensure only one thread does that */
struct mutex isr_lock;
-
- void (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
- unsigned long dty, unsigned long prd);
};
static inline struct atmel_pwm_chip *to_atmel_pwm_chip(struct pwm_chip *chip)
@@ -105,153 +110,71 @@ static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip,
writel_relaxed(val, chip->base + base + offset);
}
-static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip,
+ const struct pwm_state *state,
+ unsigned long *cprd, u32 *pres)
{
struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
- unsigned long prd, dty;
- unsigned long long div;
- unsigned int pres = 0;
- u32 val;
- int ret;
-
- if (pwm_is_enabled(pwm) && (period_ns != pwm_get_period(pwm))) {
- dev_err(chip->dev, "cannot change PWM period while enabled\n");
- return -EBUSY;
- }
+ unsigned long long cycles = state->period;
/* Calculate the period cycles and prescale value */
- div = (unsigned long long)clk_get_rate(atmel_pwm->clk) * period_ns;
- do_div(div, NSEC_PER_SEC);
+ cycles *= clk_get_rate(atmel_pwm->clk);
+ do_div(cycles, NSEC_PER_SEC);
- while (div > PWM_MAX_PRD) {
- div >>= 1;
- pres++;
- }
+ for (*pres = 0; cycles > PWM_MAX_PRD; cycles >>= 1)
+ (*pres)++;
- if (pres > PRD_MAX_PRES) {
+ if (*pres > PRD_MAX_PRES) {
dev_err(chip->dev, "pres exceeds the maximum value\n");
return -EINVAL;
}
- /* Calculate the duty cycles */
- prd = div;
- div *= duty_ns;
- do_div(div, period_ns);
- dty = prd - div;
-
- ret = clk_enable(atmel_pwm->clk);
- if (ret) {
- dev_err(chip->dev, "failed to enable PWM clock\n");
- return ret;
- }
-
- /* It is necessary to preserve CPOL, inside CMR */
- val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
- val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK);
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
- atmel_pwm->config(chip, pwm, dty, prd);
- mutex_lock(&atmel_pwm->isr_lock);
- atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
- atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm);
- mutex_unlock(&atmel_pwm->isr_lock);
-
- clk_disable(atmel_pwm->clk);
- return ret;
-}
-
-static void atmel_pwm_config_v1(struct pwm_chip *chip, struct pwm_device *pwm,
- unsigned long dty, unsigned long prd)
-{
- struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
- unsigned int val;
-
+ *cprd = cycles;
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CUPD, dty);
-
- val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
- val &= ~PWM_CMR_UPD_CDTY;
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
-
- /*
- * If the PWM channel is enabled, only update CDTY by using the update
- * register, it needs to set bit 10 of CMR to 0
- */
- if (pwm_is_enabled(pwm))
- return;
- /*
- * If the PWM channel is disabled, write value to duty and period
- * registers directly.
- */
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CDTY, dty);
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CPRD, prd);
+ return 0;
}
-static void atmel_pwm_config_v2(struct pwm_chip *chip, struct pwm_device *pwm,
- unsigned long dty, unsigned long prd)
+static void atmel_pwm_calculate_cdty(const struct pwm_state *state,
+ unsigned long cprd, unsigned long *cdty)
{
- struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+ unsigned long long cycles = state->duty_cycle;
- if (pwm_is_enabled(pwm)) {
- /*
- * If the PWM channel is enabled, using the duty update register
- * to update the value.
- */
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV2_CDTYUPD, dty);
- } else {
- /*
- * If the PWM channel is disabled, write value to duty and
- * period registers directly.
- */
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV2_CDTY, dty);
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV2_CPRD, prd);
- }
+ cycles *= cprd;
+ do_div(cycles, state->period);
+ *cdty = cprd - cycles;
}
-static int atmel_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
- enum pwm_polarity polarity)
+static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm,
+ unsigned long cdty)
{
struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
u32 val;
- int ret;
-
- val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
- if (polarity == PWM_POLARITY_NORMAL)
- val &= ~PWM_CMR_CPOL;
- else
- val |= PWM_CMR_CPOL;
-
- ret = clk_enable(atmel_pwm->clk);
- if (ret) {
- dev_err(chip->dev, "failed to enable PWM clock\n");
- return ret;
+ if (atmel_pwm->regs->duty_upd ==
+ atmel_pwm->regs->period_upd) {
+ val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+ val &= ~PWM_CMR_UPD_CDTY;
+ atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
}
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
-
- clk_disable(atmel_pwm->clk);
-
- return 0;
+ atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
+ atmel_pwm->regs->duty_upd, cdty);
}
-static int atmel_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ unsigned long cprd, unsigned long cdty)
{
struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
- int ret;
-
- ret = clk_enable(atmel_pwm->clk);
- if (ret) {
- dev_err(chip->dev, "failed to enable PWM clock\n");
- return ret;
- }
- atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);
-
- return 0;
+ atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
+ atmel_pwm->regs->duty, cdty);
+ atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm,
+ atmel_pwm->regs->period, cprd);
}
-static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm,
+ bool disable_clk)
{
struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
unsigned long timeout = jiffies + 2 * HZ;
@@ -282,37 +205,99 @@ static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
time_before(jiffies, timeout))
usleep_range(10, 100);
- clk_disable(atmel_pwm->clk);
+ if (disable_clk)
+ clk_disable(atmel_pwm->clk);
+}
+
+static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
+ struct pwm_state cstate;
+ unsigned long cprd, cdty;
+ u32 pres, val;
+ int ret;
+
+ pwm_get_state(pwm, &cstate);
+
+ if (state->enabled) {
+ if (cstate.enabled &&
+ cstate.polarity == state->polarity &&
+ cstate.period == state->period) {
+ cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
+ atmel_pwm->regs->period);
+ atmel_pwm_calculate_cdty(state, cprd, &cdty);
+ atmel_pwm_update_cdty(chip, pwm, cdty);
+ return 0;
+ }
+
+ ret = atmel_pwm_calculate_cprd_and_pres(chip, state, &cprd,
+ &pres);
+ if (ret) {
+ dev_err(chip->dev,
+ "failed to calculate cprd and prescaler\n");
+ return ret;
+ }
+
+ atmel_pwm_calculate_cdty(state, cprd, &cdty);
+
+ if (cstate.enabled) {
+ atmel_pwm_disable(chip, pwm, false);
+ } else {
+ ret = clk_enable(atmel_pwm->clk);
+ if (ret) {
+ dev_err(chip->dev, "failed to enable clock\n");
+ return ret;
+ }
+ }
+
+ /* It is necessary to preserve CPOL, inside CMR */
+ val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+ val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK);
+ if (state->polarity == PWM_POLARITY_NORMAL)
+ val &= ~PWM_CMR_CPOL;
+ else
+ val |= PWM_CMR_CPOL;
+ atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
+ atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty);
+ mutex_lock(&atmel_pwm->isr_lock);
+ atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR);
+ atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm);
+ mutex_unlock(&atmel_pwm->isr_lock);
+ atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm);
+ } else if (cstate.enabled) {
+ atmel_pwm_disable(chip, pwm, true);
+ }
+
+ return 0;
}
static const struct pwm_ops atmel_pwm_ops = {
- .config = atmel_pwm_config,
- .set_polarity = atmel_pwm_set_polarity,
- .enable = atmel_pwm_enable,
- .disable = atmel_pwm_disable,
+ .apply = atmel_pwm_apply,
.owner = THIS_MODULE,
};
-struct atmel_pwm_data {
- void (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
- unsigned long dty, unsigned long prd);
+static const struct atmel_pwm_registers atmel_pwm_regs_v1 = {
+ .period = PWMV1_CPRD,
+ .period_upd = PWMV1_CUPD,
+ .duty = PWMV1_CDTY,
+ .duty_upd = PWMV1_CUPD,
};
-static const struct atmel_pwm_data atmel_pwm_data_v1 = {
- .config = atmel_pwm_config_v1,
-};
-
-static const struct atmel_pwm_data atmel_pwm_data_v2 = {
- .config = atmel_pwm_config_v2,
+static const struct atmel_pwm_registers atmel_pwm_regs_v2 = {
+ .period = PWMV2_CPRD,
+ .period_upd = PWMV2_CPRDUPD,
+ .duty = PWMV2_CDTY,
+ .duty_upd = PWMV2_CDTYUPD,
};
static const struct platform_device_id atmel_pwm_devtypes[] = {
{
.name = "at91sam9rl-pwm",
- .driver_data = (kernel_ulong_t)&atmel_pwm_data_v1,
+ .driver_data = (kernel_ulong_t)&atmel_pwm_regs_v1,
}, {
.name = "sama5d3-pwm",
- .driver_data = (kernel_ulong_t)&atmel_pwm_data_v2,
+ .driver_data = (kernel_ulong_t)&atmel_pwm_regs_v2,
}, {
/* sentinel */
},
@@ -322,17 +307,20 @@ MODULE_DEVICE_TABLE(platform, atmel_pwm_devtypes);
static const struct of_device_id atmel_pwm_dt_ids[] = {
{
.compatible = "atmel,at91sam9rl-pwm",
- .data = &atmel_pwm_data_v1,
+ .data = &atmel_pwm_regs_v1,
}, {
.compatible = "atmel,sama5d3-pwm",
- .data = &atmel_pwm_data_v2,
+ .data = &atmel_pwm_regs_v2,
+ }, {
+ .compatible = "atmel,sama5d2-pwm",
+ .data = &atmel_pwm_regs_v2,
}, {
/* sentinel */
},
};
MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids);
-static inline const struct atmel_pwm_data *
+static inline const struct atmel_pwm_registers *
atmel_pwm_get_driver_data(struct platform_device *pdev)
{
const struct platform_device_id *id;
@@ -342,18 +330,18 @@ atmel_pwm_get_driver_data(struct platform_device *pdev)
id = platform_get_device_id(pdev);
- return (struct atmel_pwm_data *)id->driver_data;
+ return (struct atmel_pwm_registers *)id->driver_data;
}
static int atmel_pwm_probe(struct platform_device *pdev)
{
- const struct atmel_pwm_data *data;
+ const struct atmel_pwm_registers *regs;
struct atmel_pwm_chip *atmel_pwm;
struct resource *res;
int ret;
- data = atmel_pwm_get_driver_data(pdev);
- if (!data)
+ regs = atmel_pwm_get_driver_data(pdev);
+ if (!regs)
return -ENODEV;
atmel_pwm = devm_kzalloc(&pdev->dev, sizeof(*atmel_pwm), GFP_KERNEL);
@@ -385,7 +373,7 @@ static int atmel_pwm_probe(struct platform_device *pdev)
atmel_pwm->chip.base = -1;
atmel_pwm->chip.npwm = 4;
- atmel_pwm->config = data->config;
+ atmel_pwm->regs = regs;
atmel_pwm->updated_pwms = 0;
mutex_init(&atmel_pwm->isr_lock);