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pwm: atmel-tcb: Add sama5d2 support

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Add sama5d2 support. The sama5d2 has a new clock input, its gclk. Index 0
of the clock selector is the gclk instead of the peripheral clock divided
by 2.

For now, the gclk is not used because the peripheral clock divided by 8
already gives a 9.6ns resolution which is enough for most use cases.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Alexandre Belloni 2020-10-30 19:36:57 +01:00 committed by Thierry Reding
parent 061f8572a3
commit 34cbcd7258
1 changed files with 20 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

23
drivers/pwm/pwm-atmel-tcb.c
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@ -55,6 +55,7 @@ struct atmel_tcb_pwm_chip {
u8 width; u8 width;
struct regmap *regmap; struct regmap *regmap;
struct clk *clk; struct clk *clk;
struct clk *gclk;
struct clk *slow_clk; struct clk *slow_clk;
struct atmel_tcb_pwm_device *pwms[NPWM]; struct atmel_tcb_pwm_device *pwms[NPWM];
struct atmel_tcb_channel bkup; struct atmel_tcb_channel bkup;
@ -292,7 +293,7 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm); struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
struct atmel_tcb_pwm_device *atcbpwm = NULL; struct atmel_tcb_pwm_device *atcbpwm = NULL;
int i; int i = 0;
int slowclk = 0; int slowclk = 0;
unsigned period; unsigned period;
unsigned duty; unsigned duty;
@ -303,8 +304,11 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
/* /*
* Find best clk divisor: * Find best clk divisor:
* the smallest divisor which can fulfill the period_ns requirements. * the smallest divisor which can fulfill the period_ns requirements.
* If there is a gclk, the first divisor is actuallly the gclk selector
*/ */
for (i = 0; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) { if (tcbpwmc->gclk)
i = 1;
for (; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) {
if (atmel_tcb_divisors[i] == 0) { if (atmel_tcb_divisors[i] == 0) {
slowclk = i; slowclk = i;
continue; continue;
@ -383,9 +387,15 @@ static struct atmel_tcb_config tcb_sam9x5_config = {
.counter_width = 32, .counter_width = 32,
}; };
static struct atmel_tcb_config tcb_sama5d2_config = {
.counter_width = 32,
.has_gclk = 1,
};
static const struct of_device_id atmel_tcb_of_match[] = { static const struct of_device_id atmel_tcb_of_match[] = {
{ .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, }, { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
{ .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, }, { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
{ .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
{ /* sentinel */ } { /* sentinel */ }
}; };
@ -396,7 +406,7 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
const struct atmel_tcb_config *config; const struct atmel_tcb_config *config;
struct device_node *np = pdev->dev.of_node; struct device_node *np = pdev->dev.of_node;
struct regmap *regmap; struct regmap *regmap;
struct clk *clk; struct clk *clk, *gclk = NULL;
struct clk *slow_clk; struct clk *slow_clk;
char clk_name[] = "t0_clk"; char clk_name[] = "t0_clk";
int err; int err;
@ -428,6 +438,12 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
match = of_match_node(atmel_tcb_of_match, np->parent); match = of_match_node(atmel_tcb_of_match, np->parent);
config = match->data; config = match->data;
if (config->has_gclk) {
gclk = of_clk_get_by_name(np->parent, "gclk");
if (IS_ERR(gclk))
return PTR_ERR(gclk);
}
tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL); tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
if (tcbpwm == NULL) { if (tcbpwm == NULL) {
err = -ENOMEM; err = -ENOMEM;
@ -443,6 +459,7 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
tcbpwm->channel = channel; tcbpwm->channel = channel;
tcbpwm->regmap = regmap; tcbpwm->regmap = regmap;
tcbpwm->clk = clk; tcbpwm->clk = clk;
tcbpwm->gclk = gclk;
tcbpwm->slow_clk = slow_clk; tcbpwm->slow_clk = slow_clk;
tcbpwm->width = config->counter_width; tcbpwm->width = config->counter_width;