Merge tag 'pwm/for-6.15-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux
Pull pwm fixes from Uwe Kleine-König:
"A set of fixes for pwm core and various drivers
The first three patches handle clk_get_rate() returning 0 (which might
happen for example if the CCF is disabled). The first of these was
found because this triggered a warning with clang, the two others by
looking for similar issues in other drivers.
The remaining three fixes address issues in the new waveform pwm API.
Now that I worked on this a bit more, the finer details and corner
cases are better understood and the code is fixed accordingly"
* tag 'pwm/for-6.15-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux:
pwm: axi-pwmgen: Let .round_waveform_tohw() signal when request was rounded up
pwm: stm32: Search an appropriate duty_cycle if period cannot be modified
pwm: Let pwm_set_waveform() succeed even if lowlevel driver rounded up
pwm: fsl-ftm: Handle clk_get_rate() returning 0
pwm: rcar: Improve register calculation
pwm: mediatek: Prevent divide-by-zero in pwm_mediatek_config()
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index a40c511..0387bd8 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -322,7 +322,7 @@ static int __pwm_set_waveform(struct pwm_device *pwm,
const struct pwm_ops *ops = chip->ops;
char wfhw[WFHWSIZE];
struct pwm_waveform wf_rounded;
- int err;
+ int err, ret_tohw;
BUG_ON(WFHWSIZE < ops->sizeof_wfhw);
@@ -332,16 +332,16 @@ static int __pwm_set_waveform(struct pwm_device *pwm,
if (!pwm_wf_valid(wf))
return -EINVAL;
- err = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw);
- if (err)
- return err;
+ ret_tohw = __pwm_round_waveform_tohw(chip, pwm, wf, &wfhw);
+ if (ret_tohw < 0)
+ return ret_tohw;
if ((IS_ENABLED(CONFIG_PWM_DEBUG) || exact) && wf->period_length_ns) {
err = __pwm_round_waveform_fromhw(chip, pwm, &wfhw, &wf_rounded);
if (err)
return err;
- if (IS_ENABLED(CONFIG_PWM_DEBUG) && !pwm_check_rounding(wf, &wf_rounded))
+ if (IS_ENABLED(CONFIG_PWM_DEBUG) && ret_tohw == 0 && !pwm_check_rounding(wf, &wf_rounded))
dev_err(&chip->dev, "Wrong rounding: requested %llu/%llu [+%llu], result %llu/%llu [+%llu]\n",
wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns);
@@ -382,7 +382,8 @@ static int __pwm_set_waveform(struct pwm_device *pwm,
wf_rounded.duty_length_ns, wf_rounded.period_length_ns, wf_rounded.duty_offset_ns,
wf_set.duty_length_ns, wf_set.period_length_ns, wf_set.duty_offset_ns);
}
- return 0;
+
+ return ret_tohw;
}
/**
diff --git a/drivers/pwm/pwm-axi-pwmgen.c b/drivers/pwm/pwm-axi-pwmgen.c
index 4259a0db..4337c8f 100644
--- a/drivers/pwm/pwm-axi-pwmgen.c
+++ b/drivers/pwm/pwm-axi-pwmgen.c
@@ -75,6 +75,7 @@ static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip,
{
struct axi_pwmgen_waveform *wfhw = _wfhw;
struct axi_pwmgen_ddata *ddata = axi_pwmgen_ddata_from_chip(chip);
+ int ret = 0;
if (wf->period_length_ns == 0) {
*wfhw = (struct axi_pwmgen_waveform){
@@ -91,12 +92,15 @@ static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip,
if (wfhw->period_cnt == 0) {
/*
* The specified period is too short for the hardware.
- * Let's round .duty_cycle down to 0 to get a (somewhat)
- * valid result.
+ * So round up .period_cnt to 1 (i.e. the smallest
+ * possible period). With .duty_cycle and .duty_offset
+ * being less than or equal to .period, their rounded
+ * value must be 0.
*/
wfhw->period_cnt = 1;
wfhw->duty_cycle_cnt = 0;
wfhw->duty_offset_cnt = 0;
+ ret = 1;
} else {
wfhw->duty_cycle_cnt = min_t(u64,
mul_u64_u32_div(wf->duty_length_ns, ddata->clk_rate_hz, NSEC_PER_SEC),
@@ -111,7 +115,7 @@ static int axi_pwmgen_round_waveform_tohw(struct pwm_chip *chip,
pwm->hwpwm, wf->duty_length_ns, wf->period_length_ns, wf->duty_offset_ns,
ddata->clk_rate_hz, wfhw->period_cnt, wfhw->duty_cycle_cnt, wfhw->duty_offset_cnt);
- return 0;
+ return ret;
}
static int axi_pwmgen_round_waveform_fromhw(struct pwm_chip *chip, struct pwm_device *pwm,
diff --git a/drivers/pwm/pwm-fsl-ftm.c b/drivers/pwm/pwm-fsl-ftm.c
index 2510c10..c45a5fc 100644
--- a/drivers/pwm/pwm-fsl-ftm.c
+++ b/drivers/pwm/pwm-fsl-ftm.c
@@ -118,6 +118,9 @@ static unsigned int fsl_pwm_ticks_to_ns(struct fsl_pwm_chip *fpc,
unsigned long long exval;
rate = clk_get_rate(fpc->clk[fpc->period.clk_select]);
+ if (rate >> fpc->period.clk_ps == 0)
+ return 0;
+
exval = ticks;
exval *= 1000000000UL;
do_div(exval, rate >> fpc->period.clk_ps);
@@ -190,6 +193,9 @@ static unsigned int fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
unsigned int period = fpc->period.mod_period + 1;
unsigned int period_ns = fsl_pwm_ticks_to_ns(fpc, period);
+ if (!period_ns)
+ return 0;
+
duty = (unsigned long long)duty_ns * period;
do_div(duty, period_ns);
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c
index 01dfa0f..7eaab58 100644
--- a/drivers/pwm/pwm-mediatek.c
+++ b/drivers/pwm/pwm-mediatek.c
@@ -121,21 +121,25 @@ static int pwm_mediatek_config(struct pwm_chip *chip, struct pwm_device *pwm,
struct pwm_mediatek_chip *pc = to_pwm_mediatek_chip(chip);
u32 clkdiv = 0, cnt_period, cnt_duty, reg_width = PWMDWIDTH,
reg_thres = PWMTHRES;
+ unsigned long clk_rate;
u64 resolution;
int ret;
ret = pwm_mediatek_clk_enable(chip, pwm);
-
if (ret < 0)
return ret;
+ clk_rate = clk_get_rate(pc->clk_pwms[pwm->hwpwm]);
+ if (!clk_rate)
+ return -EINVAL;
+
/* Make sure we use the bus clock and not the 26MHz clock */
if (pc->soc->has_ck_26m_sel)
writel(0, pc->regs + PWM_CK_26M_SEL);
/* Using resolution in picosecond gets accuracy higher */
resolution = (u64)NSEC_PER_SEC * 1000;
- do_div(resolution, clk_get_rate(pc->clk_pwms[pwm->hwpwm]));
+ do_div(resolution, clk_rate);
cnt_period = DIV_ROUND_CLOSEST_ULL((u64)period_ns * 1000, resolution);
while (cnt_period > 8191) {
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c
index 2261789..578dbdd 100644
--- a/drivers/pwm/pwm-rcar.c
+++ b/drivers/pwm/pwm-rcar.c
@@ -8,6 +8,7 @@
* - The hardware cannot generate a 0% duty cycle.
*/
+#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
@@ -102,23 +103,24 @@ static void rcar_pwm_set_clock_control(struct rcar_pwm_chip *rp,
rcar_pwm_write(rp, value, RCAR_PWMCR);
}
-static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns,
- int period_ns)
+static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, u64 duty_ns,
+ u64 period_ns)
{
- unsigned long long one_cycle, tmp; /* 0.01 nanoseconds */
+ unsigned long long tmp;
unsigned long clk_rate = clk_get_rate(rp->clk);
u32 cyc, ph;
- one_cycle = NSEC_PER_SEC * 100ULL << div;
- do_div(one_cycle, clk_rate);
+ /* div <= 24 == RCAR_PWM_MAX_DIVISION, so the shift doesn't overflow. */
+ tmp = mul_u64_u64_div_u64(period_ns, clk_rate, (u64)NSEC_PER_SEC << div);
+ if (tmp > FIELD_MAX(RCAR_PWMCNT_CYC0_MASK))
+ tmp = FIELD_MAX(RCAR_PWMCNT_CYC0_MASK);
- tmp = period_ns * 100ULL;
- do_div(tmp, one_cycle);
- cyc = (tmp << RCAR_PWMCNT_CYC0_SHIFT) & RCAR_PWMCNT_CYC0_MASK;
+ cyc = FIELD_PREP(RCAR_PWMCNT_CYC0_MASK, tmp);
- tmp = duty_ns * 100ULL;
- do_div(tmp, one_cycle);
- ph = tmp & RCAR_PWMCNT_PH0_MASK;
+ tmp = mul_u64_u64_div_u64(duty_ns, clk_rate, (u64)NSEC_PER_SEC << div);
+ if (tmp > FIELD_MAX(RCAR_PWMCNT_PH0_MASK))
+ tmp = FIELD_MAX(RCAR_PWMCNT_PH0_MASK);
+ ph = FIELD_PREP(RCAR_PWMCNT_PH0_MASK, tmp);
/* Avoid prohibited setting */
if (cyc == 0 || ph == 0)
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index a59de4d..ec2c05c 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -103,22 +103,16 @@ static int stm32_pwm_round_waveform_tohw(struct pwm_chip *chip,
if (ret)
goto out;
- /*
- * calculate the best value for ARR for the given PSC, refuse if
- * the resulting period gets bigger than the requested one.
- */
arr = mul_u64_u64_div_u64(wf->period_length_ns, rate,
(u64)NSEC_PER_SEC * (wfhw->psc + 1));
if (arr <= wfhw->arr) {
/*
- * requested period is small than the currently
+ * requested period is smaller than the currently
* configured and unchangable period, report back the smallest
- * possible period, i.e. the current state; Initialize
- * ccr to anything valid.
+ * possible period, i.e. the current state and return 1
+ * to indicate the wrong rounding direction.
*/
- wfhw->ccr = 0;
ret = 1;
- goto out;
}
} else {
