// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) Overkiz SAS 2012 * * Author: Boris BREZILLON */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define NPWM 2 #define ATMEL_TC_ACMR_MASK (ATMEL_TC_ACPA | ATMEL_TC_ACPC | \ ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG) #define ATMEL_TC_BCMR_MASK (ATMEL_TC_BCPB | ATMEL_TC_BCPC | \ ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG) struct atmel_tcb_pwm_device { unsigned div; /* PWM clock divider */ unsigned duty; /* PWM duty expressed in clk cycles */ unsigned period; /* PWM period expressed in clk cycles */ }; struct atmel_tcb_channel { u32 enabled; u32 cmr; u32 ra; u32 rb; u32 rc; }; struct atmel_tcb_pwm_chip { spinlock_t lock; u8 channel; u8 width; struct regmap *regmap; struct clk *clk; struct clk *gclk; struct clk *slow_clk; struct atmel_tcb_pwm_device pwms[NPWM]; struct atmel_tcb_channel bkup; }; static const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128, 0, }; static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip) { return pwmchip_get_drvdata(chip); } static int atmel_tcb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_pwm_device *tcbpwm = &tcbpwmc->pwms[pwm->hwpwm]; unsigned cmr; int ret; ret = clk_prepare_enable(tcbpwmc->clk); if (ret) return ret; tcbpwm->duty = 0; tcbpwm->period = 0; tcbpwm->div = 0; guard(spinlock)(&tcbpwmc->lock); regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr); /* * Get init config from Timer Counter registers if * Timer Counter is already configured as a PWM generator. */ if (cmr & ATMEL_TC_WAVE) { if (pwm->hwpwm == 0) regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RA), &tcbpwm->duty); else regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RB), &tcbpwm->duty); tcbpwm->div = cmr & ATMEL_TC_TCCLKS; regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC), &tcbpwm->period); cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK | ATMEL_TC_BCMR_MASK); } else cmr = 0; cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0; regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr); return 0; } static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); clk_disable_unprepare(tcbpwmc->clk); } static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity polarity) { struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_pwm_device *tcbpwm = &tcbpwmc->pwms[pwm->hwpwm]; unsigned cmr; /* * If duty is 0 the timer will be stopped and we have to * configure the output correctly on software trigger: * - set output to high if PWM_POLARITY_INVERSED * - set output to low if PWM_POLARITY_NORMAL * * This is why we're reverting polarity in this case. */ if (tcbpwm->duty == 0) polarity = !polarity; regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr); /* flush old setting and set the new one */ if (pwm->hwpwm == 0) { cmr &= ~ATMEL_TC_ACMR_MASK; if (polarity == PWM_POLARITY_INVERSED) cmr |= ATMEL_TC_ASWTRG_CLEAR; else cmr |= ATMEL_TC_ASWTRG_SET; } else { cmr &= ~ATMEL_TC_BCMR_MASK; if (polarity == PWM_POLARITY_INVERSED) cmr |= ATMEL_TC_BSWTRG_CLEAR; else cmr |= ATMEL_TC_BSWTRG_SET; } regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr); /* * Use software trigger to apply the new setting. * If both PWM devices in this group are disabled we stop the clock. */ if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) { regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR), ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS); tcbpwmc->bkup.enabled = 1; } else { regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR), ATMEL_TC_SWTRG); tcbpwmc->bkup.enabled = 0; } } static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity polarity) { struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_pwm_device *tcbpwm = &tcbpwmc->pwms[pwm->hwpwm]; u32 cmr; /* * If duty is 0 the timer will be stopped and we have to * configure the output correctly on software trigger: * - set output to high if PWM_POLARITY_INVERSED * - set output to low if PWM_POLARITY_NORMAL * * This is why we're reverting polarity in this case. */ if (tcbpwm->duty == 0) polarity = !polarity; regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr); /* flush old setting and set the new one */ cmr &= ~ATMEL_TC_TCCLKS; if (pwm->hwpwm == 0) { cmr &= ~ATMEL_TC_ACMR_MASK; /* Set CMR flags according to given polarity */ if (polarity == PWM_POLARITY_INVERSED) cmr |= ATMEL_TC_ASWTRG_CLEAR; else cmr |= ATMEL_TC_ASWTRG_SET; } else { cmr &= ~ATMEL_TC_BCMR_MASK; if (polarity == PWM_POLARITY_INVERSED) cmr |= ATMEL_TC_BSWTRG_CLEAR; else cmr |= ATMEL_TC_BSWTRG_SET; } /* * If duty is 0 or equal to period there's no need to register * a specific action on RA/RB and RC compare. * The output will be configured on software trigger and keep * this config till next config call. */ if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) { if (pwm->hwpwm == 0) { if (polarity == PWM_POLARITY_INVERSED) cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR; else cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET; } else { if (polarity == PWM_POLARITY_INVERSED) cmr |= ATMEL_TC_BCPB_SET | ATMEL_TC_BCPC_CLEAR; else cmr |= ATMEL_TC_BCPB_CLEAR | ATMEL_TC_BCPC_SET; } } cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS); regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr); if (pwm->hwpwm == 0) regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RA), tcbpwm->duty); else regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RB), tcbpwm->duty); regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC), tcbpwm->period); /* Use software trigger to apply the new setting */ regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR), ATMEL_TC_SWTRG | ATMEL_TC_CLKEN); tcbpwmc->bkup.enabled = 1; return 0; } static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_pwm_device *tcbpwm = &tcbpwmc->pwms[pwm->hwpwm]; /* companion PWM sharing register values period and div */ struct atmel_tcb_pwm_device *atcbpwm = &tcbpwmc->pwms[pwm->hwpwm ^ 1]; int i = 0; int slowclk = 0; unsigned period; unsigned duty; unsigned rate = clk_get_rate(tcbpwmc->clk); unsigned long long min; unsigned long long max; /* * Find best clk divisor: * the smallest divisor which can fulfill the period_ns requirements. * If there is a gclk, the first divisor is actually the gclk selector */ if (tcbpwmc->gclk) i = 1; for (; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) { if (atmel_tcb_divisors[i] == 0) { slowclk = i; continue; } min = div_u64((u64)NSEC_PER_SEC * atmel_tcb_divisors[i], rate); max = min << tcbpwmc->width; if (max >= period_ns) break; } /* * If none of the divisor are small enough to represent period_ns * take slow clock (32KHz). */ if (i == ARRAY_SIZE(atmel_tcb_divisors)) { i = slowclk; rate = clk_get_rate(tcbpwmc->slow_clk); min = div_u64(NSEC_PER_SEC, rate); max = min << tcbpwmc->width; /* If period is too big return ERANGE error */ if (max < period_ns) return -ERANGE; } duty = div_u64(duty_ns, min); period = div_u64(period_ns, min); /* * PWM devices provided by the TCB driver are grouped by 2. * PWM devices in a given group must be configured with the * same period_ns. * * We're checking the period value of the second PWM device * in this group before applying the new config. */ if ((atcbpwm->duty > 0 && atcbpwm->duty != atcbpwm->period) && (atcbpwm->div != i || atcbpwm->period != period)) { dev_err(pwmchip_parent(chip), "failed to configure period_ns: PWM group already configured with a different value\n"); return -EINVAL; } tcbpwm->period = period; tcbpwm->div = i; tcbpwm->duty = duty; return 0; } static int atmel_tcb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); int duty_cycle, period; int ret; guard(spinlock)(&tcbpwmc->lock); if (!state->enabled) { atmel_tcb_pwm_disable(chip, pwm, state->polarity); return 0; } period = min(state->period, INT_MAX); duty_cycle = min(state->duty_cycle, INT_MAX); ret = atmel_tcb_pwm_config(chip, pwm, duty_cycle, period); if (ret) return ret; return atmel_tcb_pwm_enable(chip, pwm, state->polarity); } static const struct pwm_ops atmel_tcb_pwm_ops = { .request = atmel_tcb_pwm_request, .free = atmel_tcb_pwm_free, .apply = atmel_tcb_pwm_apply, }; static struct atmel_tcb_config tcb_rm9200_config = { .counter_width = 16, }; static struct atmel_tcb_config tcb_sam9x5_config = { .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[] = { { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, }, { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, }, { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, }, { /* sentinel */ } }; static int atmel_tcb_pwm_probe(struct platform_device *pdev) { struct pwm_chip *chip; const struct of_device_id *match; struct atmel_tcb_pwm_chip *tcbpwmc; const struct atmel_tcb_config *config; struct device_node *np = pdev->dev.of_node; char clk_name[] = "t0_clk"; int err; int channel; chip = devm_pwmchip_alloc(&pdev->dev, NPWM, sizeof(*tcbpwmc)); if (IS_ERR(chip)) return PTR_ERR(chip); tcbpwmc = to_tcb_chip(chip); err = of_property_read_u32(np, "reg", &channel); if (err < 0) { dev_err(&pdev->dev, "failed to get Timer Counter Block channel from device tree (error: %d)\n", err); return err; } tcbpwmc->regmap = syscon_node_to_regmap(np->parent); if (IS_ERR(tcbpwmc->regmap)) return PTR_ERR(tcbpwmc->regmap); tcbpwmc->slow_clk = of_clk_get_by_name(np->parent, "slow_clk"); if (IS_ERR(tcbpwmc->slow_clk)) return PTR_ERR(tcbpwmc->slow_clk); clk_name[1] += channel; tcbpwmc->clk = of_clk_get_by_name(np->parent, clk_name); if (IS_ERR(tcbpwmc->clk)) tcbpwmc->clk = of_clk_get_by_name(np->parent, "t0_clk"); if (IS_ERR(tcbpwmc->clk)) { err = PTR_ERR(tcbpwmc->clk); goto err_slow_clk; } match = of_match_node(atmel_tcb_of_match, np->parent); config = match->data; if (config->has_gclk) { tcbpwmc->gclk = of_clk_get_by_name(np->parent, "gclk"); if (IS_ERR(tcbpwmc->gclk)) { err = PTR_ERR(tcbpwmc->gclk); goto err_clk; } } chip->ops = &atmel_tcb_pwm_ops; tcbpwmc->channel = channel; tcbpwmc->width = config->counter_width; err = clk_prepare_enable(tcbpwmc->slow_clk); if (err) goto err_gclk; spin_lock_init(&tcbpwmc->lock); err = pwmchip_add(chip); if (err < 0) goto err_disable_clk; platform_set_drvdata(pdev, chip); return 0; err_disable_clk: clk_disable_unprepare(tcbpwmc->slow_clk); err_gclk: clk_put(tcbpwmc->gclk); err_clk: clk_put(tcbpwmc->clk); err_slow_clk: clk_put(tcbpwmc->slow_clk); return err; } static void atmel_tcb_pwm_remove(struct platform_device *pdev) { struct pwm_chip *chip = platform_get_drvdata(pdev); struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); pwmchip_remove(chip); clk_disable_unprepare(tcbpwmc->slow_clk); clk_put(tcbpwmc->gclk); clk_put(tcbpwmc->clk); clk_put(tcbpwmc->slow_clk); } static const struct of_device_id atmel_tcb_pwm_dt_ids[] = { { .compatible = "atmel,tcb-pwm", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids); static int atmel_tcb_pwm_suspend(struct device *dev) { struct pwm_chip *chip = dev_get_drvdata(dev); struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_channel *chan = &tcbpwmc->bkup; unsigned int channel = tcbpwmc->channel; regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(channel, CMR), &chan->cmr); regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(channel, RA), &chan->ra); regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(channel, RB), &chan->rb); regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(channel, RC), &chan->rc); return 0; } static int atmel_tcb_pwm_resume(struct device *dev) { struct pwm_chip *chip = dev_get_drvdata(dev); struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); struct atmel_tcb_channel *chan = &tcbpwmc->bkup; unsigned int channel = tcbpwmc->channel; regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(channel, CMR), chan->cmr); regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(channel, RA), chan->ra); regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(channel, RB), chan->rb); regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(channel, RC), chan->rc); if (chan->enabled) regmap_write(tcbpwmc->regmap, ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, ATMEL_TC_REG(channel, CCR)); return 0; } static DEFINE_SIMPLE_DEV_PM_OPS(atmel_tcb_pwm_pm_ops, atmel_tcb_pwm_suspend, atmel_tcb_pwm_resume); static struct platform_driver atmel_tcb_pwm_driver = { .driver = { .name = "atmel-tcb-pwm", .of_match_table = atmel_tcb_pwm_dt_ids, .pm = pm_ptr(&atmel_tcb_pwm_pm_ops), }, .probe = atmel_tcb_pwm_probe, .remove = atmel_tcb_pwm_remove, }; module_platform_driver(atmel_tcb_pwm_driver); MODULE_AUTHOR("Boris BREZILLON "); MODULE_DESCRIPTION("Atmel Timer Counter Pulse Width Modulation Driver"); MODULE_LICENSE("GPL v2");