Hi,
Le jeu. 13 déc. 2018 à 10:30, Uwe Kleine-König
<u.kleine-koe...@pengutronix.de> a écrit :
Hello,
On Wed, Dec 12, 2018 at 11:09:06PM +0100, Paul Cercueil wrote:
[...]
static int jz4740_pwm_enable(struct pwm_chip *chip, struct
pwm_device *pwm)
{
- uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
+ struct jz4740_pwm_chip *jz = to_jz4740(chip);
- ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
- jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
- jz4740_timer_enable(pwm->hwpwm);
+ /* Enable PWM output */
+ regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),
+ TCU_TCSR_PWM_EN, TCU_TCSR_PWM_EN);
Usually follow-up lines are indented to the matching parenthesis.
OK.
[...]
static int jz4740_pwm_config(struct pwm_chip *chip, struct
pwm_device *pwm,
int duty_ns, int period_ns)
{
struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
+ struct clk *clk = jz4740->clks[pwm->hwpwm];
+ unsigned long rate, new_rate, period, duty;
unsigned long long tmp;
- unsigned long period, duty;
- unsigned int prescaler = 0;
- uint16_t ctrl;
+ unsigned int tcsr;
bool is_enabled;
- tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
- do_div(tmp, 1000000000);
- period = tmp;
+ rate = clk_get_rate(clk);
+
+ for (;;) {
+ tmp = (unsigned long long) rate * period_ns;
+ do_div(tmp, 1000000000);
- while (period > 0xffff && prescaler < 6) {
- period >>= 2;
- ++prescaler;
+ if (tmp <= 0xffff)
+ break;
+
+ new_rate = clk_round_rate(clk, rate / 2);
+
+ if (new_rate < rate)
+ rate = new_rate;
+ else
+ return -EINVAL;
}
- if (prescaler == 6)
- return -EINVAL;
+ clk_set_rate(clk, rate);
Maybe this could better live in a separate patch. If you split still
further to have the conversion to regmap in a single patch, then the
conversion to the clk_* functions and then improve the algorithm for
the
clk settings each of the patches is easier to review than this one
patch
that does all three things at once.
I can try.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König
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