bool has_enable_bits;
};
+struct fsl_pwm_periodcfg {
+ enum fsl_pwm_clk clk_select;
+ unsigned int clk_ps;
+ unsigned int mod_period;
+};
+
struct fsl_pwm_chip {
struct pwm_chip chip;
-
struct mutex lock;
-
- unsigned int cnt_select;
- unsigned int clk_ps;
-
struct regmap *regmap;
- int period_ns;
+ /* This value is valid iff a pwm is running */
+ struct fsl_pwm_periodcfg period;
struct clk *ipg_clk;
struct clk *clk[FSL_PWM_CLK_MAX];
return container_of(chip, struct fsl_pwm_chip, chip);
}
+static void ftm_clear_write_protection(struct fsl_pwm_chip *fpc)
+{
+ u32 val;
+
+ regmap_read(fpc->regmap, FTM_FMS, &val);
+ if (val & FTM_FMS_WPEN)
+ regmap_update_bits(fpc->regmap, FTM_MODE, FTM_MODE_WPDIS,
+ FTM_MODE_WPDIS);
+}
+
+static void ftm_set_write_protection(struct fsl_pwm_chip *fpc)
+{
+ regmap_update_bits(fpc->regmap, FTM_FMS, FTM_FMS_WPEN, FTM_FMS_WPEN);
+}
+
+static bool fsl_pwm_periodcfg_are_equal(const struct fsl_pwm_periodcfg *a,
+ const struct fsl_pwm_periodcfg *b)
+{
+ if (a->clk_select != b->clk_select)
+ return false;
+ if (a->clk_ps != b->clk_ps)
+ return false;
+ if (a->mod_period != b->mod_period)
+ return false;
+ return true;
+}
+
static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
clk_disable_unprepare(fpc->ipg_clk);
}
-static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
- enum fsl_pwm_clk index)
+static unsigned int fsl_pwm_ticks_to_ns(struct fsl_pwm_chip *fpc,
+ unsigned int ticks)
{
- unsigned long sys_rate, cnt_rate;
- unsigned long long ratio;
-
- sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]);
- if (!sys_rate)
- return -EINVAL;
-
- cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]);
- if (!cnt_rate)
- return -EINVAL;
-
- switch (index) {
- case FSL_PWM_CLK_SYS:
- fpc->clk_ps = 1;
- break;
- case FSL_PWM_CLK_FIX:
- ratio = 2 * cnt_rate - 1;
- do_div(ratio, sys_rate);
- fpc->clk_ps = ratio;
- break;
- case FSL_PWM_CLK_EXT:
- ratio = 4 * cnt_rate - 1;
- do_div(ratio, sys_rate);
- fpc->clk_ps = ratio;
- break;
- default:
- return -EINVAL;
- }
-
- return 0;
+ unsigned long rate;
+ unsigned long long exval;
+
+ rate = clk_get_rate(fpc->clk[fpc->period.clk_select]);
+ exval = ticks;
+ exval *= 1000000000UL;
+ do_div(exval, rate >> fpc->period.clk_ps);
+ return exval;
}
-static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
- unsigned long period_ns)
+static bool fsl_pwm_calculate_period_clk(struct fsl_pwm_chip *fpc,
+ unsigned int period_ns,
+ enum fsl_pwm_clk index,
+ struct fsl_pwm_periodcfg *periodcfg
+ )
{
- unsigned long long c, c0;
+ unsigned long long c;
+ unsigned int ps;
- c = clk_get_rate(fpc->clk[fpc->cnt_select]);
+ c = clk_get_rate(fpc->clk[index]);
c = c * period_ns;
do_div(c, 1000000000UL);
- do {
- c0 = c;
- do_div(c0, (1 << fpc->clk_ps));
- if (c0 <= 0xFFFF)
- return (unsigned long)c0;
- } while (++fpc->clk_ps < 8);
-
- return 0;
-}
-
-static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc,
- unsigned long period_ns,
- enum fsl_pwm_clk index)
-{
- int ret;
+ if (c == 0)
+ return false;
- ret = fsl_pwm_calculate_default_ps(fpc, index);
- if (ret) {
- dev_err(fpc->chip.dev,
- "failed to calculate default prescaler: %d\n",
- ret);
- return 0;
+ for (ps = 0; ps < 8 ; ++ps, c >>= 1) {
+ if (c <= 0x10000) {
+ periodcfg->clk_select = index;
+ periodcfg->clk_ps = ps;
+ periodcfg->mod_period = c - 1;
+ return true;
+ }
}
-
- return fsl_pwm_calculate_cycles(fpc, period_ns);
+ return false;
}
-static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
- unsigned long period_ns)
+static bool fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
+ unsigned int period_ns,
+ struct fsl_pwm_periodcfg *periodcfg)
{
enum fsl_pwm_clk m0, m1;
- unsigned long fix_rate, ext_rate, cycles;
+ unsigned long fix_rate, ext_rate;
+ bool ret;
- cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
- FSL_PWM_CLK_SYS);
- if (cycles) {
- fpc->cnt_select = FSL_PWM_CLK_SYS;
- return cycles;
- }
+ ret = fsl_pwm_calculate_period_clk(fpc, period_ns, FSL_PWM_CLK_SYS,
+ periodcfg);
+ if (ret)
+ return true;
fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
m1 = FSL_PWM_CLK_FIX;
}
- cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
- if (cycles) {
- fpc->cnt_select = m0;
- return cycles;
- }
-
- fpc->cnt_select = m1;
+ ret = fsl_pwm_calculate_period_clk(fpc, period_ns, m0, periodcfg);
+ if (ret)
+ return true;
- return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1);
+ return fsl_pwm_calculate_period_clk(fpc, period_ns, m1, periodcfg);
}
-static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
- unsigned long period_ns,
- unsigned long duty_ns)
+static unsigned int fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
+ unsigned int duty_ns)
{
unsigned long long duty;
- u32 val;
- regmap_read(fpc->regmap, FTM_MOD, &val);
- duty = (unsigned long long)duty_ns * (val + 1);
+ unsigned int period = fpc->period.mod_period + 1;
+ unsigned int period_ns = fsl_pwm_ticks_to_ns(fpc, period);
+
+ duty = (unsigned long long)duty_ns * period;
do_div(duty, period_ns);
- return (unsigned long)duty;
+ return (unsigned int)duty;
}
-static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+static bool fsl_pwm_is_any_pwm_enabled(struct fsl_pwm_chip *fpc,
+ struct pwm_device *pwm)
{
- struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
- u32 period, duty;
+ u32 val;
- mutex_lock(&fpc->lock);
+ regmap_read(fpc->regmap, FTM_OUTMASK, &val);
+ if (~val & 0xFF)
+ return true;
+ else
+ return false;
+}
+
+static bool fsl_pwm_is_other_pwm_enabled(struct fsl_pwm_chip *fpc,
+ struct pwm_device *pwm)
+{
+ u32 val;
+ regmap_read(fpc->regmap, FTM_OUTMASK, &val);
+ if (~(val | BIT(pwm->hwpwm)) & 0xFF)
+ return true;
+ else
+ return false;
+}
+
+static int fsl_pwm_apply_config(struct fsl_pwm_chip *fpc,
+ struct pwm_device *pwm,
+ struct pwm_state *newstate)
+{
+ unsigned int duty;
+ u32 reg_polarity;
+
+ struct fsl_pwm_periodcfg periodcfg;
+ bool do_write_period = false;
+
+ if (!fsl_pwm_calculate_period(fpc, newstate->period, &periodcfg)) {
+ dev_err(fpc->chip.dev, "failed to calculate new period\n");
+ return -EINVAL;
+ }
+
+ if (!fsl_pwm_is_any_pwm_enabled(fpc, pwm))
+ do_write_period = true;
/*
* The Freescale FTM controller supports only a single period for
- * all PWM channels, therefore incompatible changes need to be
- * refused.
+ * all PWM channels, therefore verify if the newly computed period
+ * is different than the current period being used. In such case
+ * we allow to change the period only if no other pwm is running.
*/
- if (fpc->period_ns && fpc->period_ns != period_ns) {
- dev_err(fpc->chip.dev,
- "conflicting period requested for PWM %u\n",
- pwm->hwpwm);
- mutex_unlock(&fpc->lock);
- return -EBUSY;
+ else if (!fsl_pwm_periodcfg_are_equal(&fpc->period, &periodcfg)) {
+ if (fsl_pwm_is_other_pwm_enabled(fpc, pwm)) {
+ dev_err(fpc->chip.dev,
+ "Cannot change period for PWM %u, disable other PWMs first\n",
+ pwm->hwpwm);
+ return -EBUSY;
+ }
+ if (fpc->period.clk_select != periodcfg.clk_select) {
+ int ret;
+ enum fsl_pwm_clk oldclk = fpc->period.clk_select;
+ enum fsl_pwm_clk newclk = periodcfg.clk_select;
+
+ ret = clk_prepare_enable(fpc->clk[newclk]);
+ if (ret)
+ return ret;
+ clk_disable_unprepare(fpc->clk[oldclk]);
+ }
+ do_write_period = true;
}
- if (!fpc->period_ns && duty_ns) {
- period = fsl_pwm_calculate_period(fpc, period_ns);
- if (!period) {
- dev_err(fpc->chip.dev, "failed to calculate period\n");
- mutex_unlock(&fpc->lock);
- return -EINVAL;
- }
+ ftm_clear_write_protection(fpc);
+ if (do_write_period) {
+ regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
+ FTM_SC_CLK(periodcfg.clk_select));
regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
- fpc->clk_ps);
- regmap_write(fpc->regmap, FTM_MOD, period - 1);
+ periodcfg.clk_ps);
+ regmap_write(fpc->regmap, FTM_MOD, periodcfg.mod_period);
- fpc->period_ns = period_ns;
+ fpc->period = periodcfg;
}
- mutex_unlock(&fpc->lock);
-
- duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
+ duty = fsl_pwm_calculate_duty(fpc, newstate->duty_cycle);
regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
FTM_CSC_MSB | FTM_CSC_ELSB);
regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
- return 0;
-}
-
-static int fsl_pwm_set_polarity(struct pwm_chip *chip,
- struct pwm_device *pwm,
- enum pwm_polarity polarity)
-{
- struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
- u32 val;
+ reg_polarity = 0;
+ if (newstate->polarity == PWM_POLARITY_INVERSED)
+ reg_polarity = BIT(pwm->hwpwm);
- regmap_read(fpc->regmap, FTM_POL, &val);
+ regmap_update_bits(fpc->regmap, FTM_POL, BIT(pwm->hwpwm), reg_polarity);
- if (polarity == PWM_POLARITY_INVERSED)
- val |= BIT(pwm->hwpwm);
- else
- val &= ~BIT(pwm->hwpwm);
+ newstate->period = fsl_pwm_ticks_to_ns(fpc,
+ fpc->period.mod_period + 1);
+ newstate->duty_cycle = fsl_pwm_ticks_to_ns(fpc, duty);
- regmap_write(fpc->regmap, FTM_POL, val);
+ ftm_set_write_protection(fpc);
return 0;
}
-static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
-{
- int ret;
-
- /* select counter clock source */
- regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
- FTM_SC_CLK(fpc->cnt_select));
-
- ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
- if (ret)
- return ret;
-
- ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
- if (ret) {
- clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
- return ret;
- }
-
- return 0;
-}
-
-static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+static int fsl_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *newstate)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
- int ret;
-
- mutex_lock(&fpc->lock);
- regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm), 0);
+ struct pwm_state *oldstate = &pwm->state;
+ int ret = 0;
- ret = fsl_counter_clock_enable(fpc);
- mutex_unlock(&fpc->lock);
+ /*
+ * oldstate to newstate : action
+ *
+ * disabled to disabled : ignore
+ * enabled to disabled : disable
+ * enabled to enabled : update settings
+ * disabled to enabled : update settings + enable
+ */
- return ret;
-}
+ mutex_lock(&fpc->lock);
-static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
-{
- struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
- u32 val;
+ if (!newstate->enabled) {
+ if (oldstate->enabled) {
+ regmap_update_bits(fpc->regmap, FTM_OUTMASK,
+ BIT(pwm->hwpwm), BIT(pwm->hwpwm));
+ clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
+ clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
+ }
- mutex_lock(&fpc->lock);
- regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
- BIT(pwm->hwpwm));
+ goto end_mutex;
+ }
- clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
- clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
+ ret = fsl_pwm_apply_config(fpc, pwm, newstate);
+ if (ret)
+ goto end_mutex;
+
+ /* check if need to enable */
+ if (!oldstate->enabled) {
+ ret = clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
+ if (ret)
+ goto end_mutex;
+
+ ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
+ if (ret) {
+ clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
+ goto end_mutex;
+ }
- regmap_read(fpc->regmap, FTM_OUTMASK, &val);
- if ((val & 0xFF) == 0xFF)
- fpc->period_ns = 0;
+ regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
+ 0);
+ }
+end_mutex:
mutex_unlock(&fpc->lock);
+ return ret;
}
static const struct pwm_ops fsl_pwm_ops = {
.request = fsl_pwm_request,
.free = fsl_pwm_free,
- .config = fsl_pwm_config,
- .set_polarity = fsl_pwm_set_polarity,
- .enable = fsl_pwm_enable,
- .disable = fsl_pwm_disable,
+ .apply = fsl_pwm_apply,
.owner = THIS_MODULE,
};
static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
+ case FTM_FMS:
+ case FTM_MODE:
case FTM_CNT:
return true;
}
continue;
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
- clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
+ clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
}
return 0;
if (!pwm_is_enabled(pwm))
continue;
- clk_prepare_enable(fpc->clk[fpc->cnt_select]);
+ clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
}
git.samba.org / sfrench / cifs-2.6.git / blobdiff