pwm: meson: Add check for error from clk_round_rate()

[ Upstream commit 3e551115aee079931b82e1ec78c05f3d5033473f ]

clk_round_rate() can return not only zero if requested frequency can not
be provided but also negative error code so add check for it too.

Also change type of variable holding clk_round_rate() result from
unsigned long to long. It's safe due to clk_round_rate() returns long.

Fixes: 329db102a26d ("pwm: meson: make full use of common clock framework")
Signed-off-by: Dmitry Rokosov <ddrokosov@salutedevices.com>
Signed-off-by: George Stark <gnstark@salutedevices.com>
Link: https://lore.kernel.org/r/20240425171253.2752877-3-gnstark@salutedevices.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 8f67d6ba443de3dea0a8520b8138c94d9fd54a38..6fefa80af0a4cd9c959c8d755eeb9787d8861f47 100644 (file)
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -149,7 +149,7 @@ static int meson_pwm_calc(struct pwm_chip *chip, struct pwm_device *pwm,
        struct meson_pwm *meson = to_meson_pwm(chip);
        struct meson_pwm_channel *channel = &meson->channels[pwm->hwpwm];
        unsigned int cnt, duty_cnt;
-       unsigned long fin_freq;
+       long fin_freq;
        u64 duty, period, freq;
 
        duty = state->duty_cycle;
@@ -169,12 +169,13 @@ static int meson_pwm_calc(struct pwm_chip *chip, struct pwm_device *pwm,
                freq = ULONG_MAX;
 
        fin_freq = clk_round_rate(channel->clk, freq);
-       if (fin_freq == 0) {
-               dev_err(pwmchip_parent(chip), "invalid source clock frequency\n");
-               return -EINVAL;
+       if (fin_freq <= 0) {
+               dev_err(pwmchip_parent(chip),
+                       "invalid source clock frequency %llu\n", freq);
+               return fin_freq ? fin_freq : -EINVAL;
        }
 
-       dev_dbg(pwmchip_parent(chip), "fin_freq: %lu Hz\n", fin_freq);
+       dev_dbg(pwmchip_parent(chip), "fin_freq: %ld Hz\n", fin_freq);
 
        cnt = div_u64(fin_freq * period, NSEC_PER_SEC);
        if (cnt > 0xffff) {