#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)
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;
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 */
},
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;
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);
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);
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