diff options
Diffstat (limited to 'drivers/pwm/pwm-renesas-tpu.c')
| -rw-r--r-- | drivers/pwm/pwm-renesas-tpu.c | 317 |
1 files changed, 180 insertions, 137 deletions
diff --git a/drivers/pwm/pwm-renesas-tpu.c b/drivers/pwm/pwm-renesas-tpu.c index 4381df90a527..d7311614c846 100644 --- a/drivers/pwm/pwm-renesas-tpu.c +++ b/drivers/pwm/pwm-renesas-tpu.c @@ -89,71 +89,71 @@ struct tpu_device { #define to_tpu_device(c) container_of(c, struct tpu_device, chip) -static void tpu_pwm_write(struct tpu_pwm_device *pwm, int reg_nr, u16 value) +static void tpu_pwm_write(struct tpu_pwm_device *tpd, int reg_nr, u16 value) { - void __iomem *base = pwm->tpu->base + TPU_CHANNEL_OFFSET - + pwm->channel * TPU_CHANNEL_SIZE; + void __iomem *base = tpd->tpu->base + TPU_CHANNEL_OFFSET + + tpd->channel * TPU_CHANNEL_SIZE; iowrite16(value, base + reg_nr); } -static void tpu_pwm_set_pin(struct tpu_pwm_device *pwm, +static void tpu_pwm_set_pin(struct tpu_pwm_device *tpd, enum tpu_pin_state state) { static const char * const states[] = { "inactive", "PWM", "active" }; - dev_dbg(&pwm->tpu->pdev->dev, "%u: configuring pin as %s\n", - pwm->channel, states[state]); + dev_dbg(&tpd->tpu->pdev->dev, "%u: configuring pin as %s\n", + tpd->channel, states[state]); switch (state) { case TPU_PIN_INACTIVE: - tpu_pwm_write(pwm, TPU_TIORn, - pwm->polarity == PWM_POLARITY_INVERSED ? + tpu_pwm_write(tpd, TPU_TIORn, + tpd->polarity == PWM_POLARITY_INVERSED ? TPU_TIOR_IOA_1 : TPU_TIOR_IOA_0); break; case TPU_PIN_PWM: - tpu_pwm_write(pwm, TPU_TIORn, - pwm->polarity == PWM_POLARITY_INVERSED ? + tpu_pwm_write(tpd, TPU_TIORn, + tpd->polarity == PWM_POLARITY_INVERSED ? TPU_TIOR_IOA_0_SET : TPU_TIOR_IOA_1_CLR); break; case TPU_PIN_ACTIVE: - tpu_pwm_write(pwm, TPU_TIORn, - pwm->polarity == PWM_POLARITY_INVERSED ? + tpu_pwm_write(tpd, TPU_TIORn, + tpd->polarity == PWM_POLARITY_INVERSED ? TPU_TIOR_IOA_0 : TPU_TIOR_IOA_1); break; } } -static void tpu_pwm_start_stop(struct tpu_pwm_device *pwm, int start) +static void tpu_pwm_start_stop(struct tpu_pwm_device *tpd, int start) { unsigned long flags; u16 value; - spin_lock_irqsave(&pwm->tpu->lock, flags); - value = ioread16(pwm->tpu->base + TPU_TSTR); + spin_lock_irqsave(&tpd->tpu->lock, flags); + value = ioread16(tpd->tpu->base + TPU_TSTR); if (start) - value |= 1 << pwm->channel; + value |= 1 << tpd->channel; else - value &= ~(1 << pwm->channel); + value &= ~(1 << tpd->channel); - iowrite16(value, pwm->tpu->base + TPU_TSTR); - spin_unlock_irqrestore(&pwm->tpu->lock, flags); + iowrite16(value, tpd->tpu->base + TPU_TSTR); + spin_unlock_irqrestore(&tpd->tpu->lock, flags); } -static int tpu_pwm_timer_start(struct tpu_pwm_device *pwm) +static int tpu_pwm_timer_start(struct tpu_pwm_device *tpd) { int ret; - if (!pwm->timer_on) { + if (!tpd->timer_on) { /* Wake up device and enable clock. */ - pm_runtime_get_sync(&pwm->tpu->pdev->dev); - ret = clk_prepare_enable(pwm->tpu->clk); + pm_runtime_get_sync(&tpd->tpu->pdev->dev); + ret = clk_prepare_enable(tpd->tpu->clk); if (ret) { - dev_err(&pwm->tpu->pdev->dev, "cannot enable clock\n"); + dev_err(&tpd->tpu->pdev->dev, "cannot enable clock\n"); return ret; } - pwm->timer_on = true; + tpd->timer_on = true; } /* @@ -161,8 +161,8 @@ static int tpu_pwm_timer_start(struct tpu_pwm_device *pwm) * completely. First drive the pin to the inactive state to avoid * glitches. */ - tpu_pwm_set_pin(pwm, TPU_PIN_INACTIVE); - tpu_pwm_start_stop(pwm, false); + tpu_pwm_set_pin(tpd, TPU_PIN_INACTIVE); + tpu_pwm_start_stop(tpd, false); /* * - Clear TCNT on TGRB match @@ -172,142 +172,168 @@ static int tpu_pwm_timer_start(struct tpu_pwm_device *pwm) * - Output 1 until TGRA, output 0 until TGRB (active high polarity * - PWM mode */ - tpu_pwm_write(pwm, TPU_TCRn, TPU_TCR_CCLR_TGRB | TPU_TCR_CKEG_RISING | - pwm->prescaler); - tpu_pwm_write(pwm, TPU_TMDRn, TPU_TMDR_MD_PWM); - tpu_pwm_set_pin(pwm, TPU_PIN_PWM); - tpu_pwm_write(pwm, TPU_TGRAn, pwm->duty); - tpu_pwm_write(pwm, TPU_TGRBn, pwm->period); + tpu_pwm_write(tpd, TPU_TCRn, TPU_TCR_CCLR_TGRB | TPU_TCR_CKEG_RISING | + tpd->prescaler); + tpu_pwm_write(tpd, TPU_TMDRn, TPU_TMDR_MD_PWM); + tpu_pwm_set_pin(tpd, TPU_PIN_PWM); + tpu_pwm_write(tpd, TPU_TGRAn, tpd->duty); + tpu_pwm_write(tpd, TPU_TGRBn, tpd->period); - dev_dbg(&pwm->tpu->pdev->dev, "%u: TGRA 0x%04x TGRB 0x%04x\n", - pwm->channel, pwm->duty, pwm->period); + dev_dbg(&tpd->tpu->pdev->dev, "%u: TGRA 0x%04x TGRB 0x%04x\n", + tpd->channel, tpd->duty, tpd->period); /* Start the channel. */ - tpu_pwm_start_stop(pwm, true); + tpu_pwm_start_stop(tpd, true); return 0; } -static void tpu_pwm_timer_stop(struct tpu_pwm_device *pwm) +static void tpu_pwm_timer_stop(struct tpu_pwm_device *tpd) { - if (!pwm->timer_on) + if (!tpd->timer_on) return; /* Disable channel. */ - tpu_pwm_start_stop(pwm, false); + tpu_pwm_start_stop(tpd, false); /* Stop clock and mark device as idle. */ - clk_disable_unprepare(pwm->tpu->clk); - pm_runtime_put(&pwm->tpu->pdev->dev); + clk_disable_unprepare(tpd->tpu->clk); + pm_runtime_put(&tpd->tpu->pdev->dev); - pwm->timer_on = false; + tpd->timer_on = false; } /* ----------------------------------------------------------------------------- * PWM API */ -static int tpu_pwm_request(struct pwm_chip *chip, struct pwm_device *_pwm) +static int tpu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { struct tpu_device *tpu = to_tpu_device(chip); - struct tpu_pwm_device *pwm; + struct tpu_pwm_device *tpd; - if (_pwm->hwpwm >= TPU_CHANNEL_MAX) + if (pwm->hwpwm >= TPU_CHANNEL_MAX) return -EINVAL; - pwm = kzalloc(sizeof(*pwm), GFP_KERNEL); - if (pwm == NULL) + tpd = kzalloc(sizeof(*tpd), GFP_KERNEL); + if (tpd == NULL) return -ENOMEM; - pwm->tpu = tpu; - pwm->channel = _pwm->hwpwm; - pwm->polarity = PWM_POLARITY_NORMAL; - pwm->prescaler = 0; - pwm->period = 0; - pwm->duty = 0; + tpd->tpu = tpu; + tpd->channel = pwm->hwpwm; + tpd->polarity = PWM_POLARITY_NORMAL; + tpd->prescaler = 0; + tpd->period = 0; + tpd->duty = 0; - pwm->timer_on = false; + tpd->timer_on = false; - pwm_set_chip_data(_pwm, pwm); + pwm_set_chip_data(pwm, tpd); return 0; } -static void tpu_pwm_free(struct pwm_chip *chip, struct pwm_device *_pwm) +static void tpu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { - struct tpu_pwm_device *pwm = pwm_get_chip_data(_pwm); + struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); - tpu_pwm_timer_stop(pwm); - kfree(pwm); + tpu_pwm_timer_stop(tpd); + kfree(tpd); } -static int tpu_pwm_config(struct pwm_chip *chip, struct pwm_device *_pwm, - int duty_ns, int period_ns) +static int tpu_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + u64 duty_ns, u64 period_ns, bool enabled) { - static const unsigned int prescalers[] = { 1, 4, 16, 64 }; - struct tpu_pwm_device *pwm = pwm_get_chip_data(_pwm); + struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); struct tpu_device *tpu = to_tpu_device(chip); unsigned int prescaler; bool duty_only = false; u32 clk_rate; - u32 period; + u64 period; u32 duty; int ret; + clk_rate = clk_get_rate(tpu->clk); + if (unlikely(clk_rate > NSEC_PER_SEC)) { + /* + * This won't happen in the nearer future, so this is only a + * safeguard to prevent the following calculation from + * overflowing. With this clk_rate * period_ns / NSEC_PER_SEC is + * not greater than period_ns and so fits into an u64. + */ + return -EINVAL; + } + + period = mul_u64_u64_div_u64(clk_rate, period_ns, NSEC_PER_SEC); + /* - * Pick a prescaler to avoid overflowing the counter. - * TODO: Pick the highest acceptable prescaler. + * Find the minimal prescaler in [0..3] such that + * + * period >> (2 * prescaler) < 0x10000 + * + * This could be calculated using something like: + * + * prescaler = max(ilog2(period) / 2, 7) - 7; + * + * but given there are only four allowed results and that ilog2 isn't + * cheap on all platforms using a switch statement is more effective. */ - clk_rate = clk_get_rate(tpu->clk); + switch (period) { + case 1 ... 0xffff: + prescaler = 0; + break; - for (prescaler = 0; prescaler < ARRAY_SIZE(prescalers); ++prescaler) { - period = clk_rate / prescalers[prescaler] - / (NSEC_PER_SEC / period_ns); - if (period <= 0xffff) - break; - } + case 0x10000 ... 0x3ffff: + prescaler = 1; + break; - if (prescaler == ARRAY_SIZE(prescalers) || period == 0) { - dev_err(&tpu->pdev->dev, "clock rate mismatch\n"); - return -ENOTSUPP; + case 0x40000 ... 0xfffff: + prescaler = 2; + break; + + case 0x100000 ... 0x3fffff: + prescaler = 3; + break; + + default: + return -EINVAL; } - if (duty_ns) { - duty = clk_rate / prescalers[prescaler] - / (NSEC_PER_SEC / duty_ns); - if (duty > period) - return -EINVAL; - } else { + period >>= 2 * prescaler; + + if (duty_ns) + duty = mul_u64_u64_div_u64(clk_rate, duty_ns, + (u64)NSEC_PER_SEC << (2 * prescaler)); + else duty = 0; - } dev_dbg(&tpu->pdev->dev, "rate %u, prescaler %u, period %u, duty %u\n", - clk_rate, prescalers[prescaler], period, duty); + clk_rate, 1 << (2 * prescaler), (u32)period, duty); - if (pwm->prescaler == prescaler && pwm->period == period) + if (tpd->prescaler == prescaler && tpd->period == period) duty_only = true; - pwm->prescaler = prescaler; - pwm->period = period; - pwm->duty = duty; + tpd->prescaler = prescaler; + tpd->period = period; + tpd->duty = duty; /* If the channel is disabled we're done. */ - if (!pwm_is_enabled(_pwm)) + if (!enabled) return 0; - if (duty_only && pwm->timer_on) { + if (duty_only && tpd->timer_on) { /* * If only the duty cycle changed and the timer is already * running, there's no need to reconfigure it completely, Just * modify the duty cycle. */ - tpu_pwm_write(pwm, TPU_TGRAn, pwm->duty); - dev_dbg(&tpu->pdev->dev, "%u: TGRA 0x%04x\n", pwm->channel, - pwm->duty); + tpu_pwm_write(tpd, TPU_TGRAn, tpd->duty); + dev_dbg(&tpu->pdev->dev, "%u: TGRA 0x%04x\n", tpd->channel, + tpd->duty); } else { /* Otherwise perform a full reconfiguration. */ - ret = tpu_pwm_timer_start(pwm); + ret = tpu_pwm_timer_start(tpd); if (ret < 0) return ret; } @@ -317,29 +343,29 @@ static int tpu_pwm_config(struct pwm_chip *chip, struct pwm_device *_pwm, * To avoid running the timer when not strictly required, handle * 0% and 100% duty cycles as fixed levels and stop the timer. */ - tpu_pwm_set_pin(pwm, duty ? TPU_PIN_ACTIVE : TPU_PIN_INACTIVE); - tpu_pwm_timer_stop(pwm); + tpu_pwm_set_pin(tpd, duty ? TPU_PIN_ACTIVE : TPU_PIN_INACTIVE); + tpu_pwm_timer_stop(tpd); } return 0; } -static int tpu_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *_pwm, +static int tpu_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity polarity) { - struct tpu_pwm_device *pwm = pwm_get_chip_data(_pwm); + struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); - pwm->polarity = polarity; + tpd->polarity = polarity; return 0; } -static int tpu_pwm_enable(struct pwm_chip *chip, struct pwm_device *_pwm) +static int tpu_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { - struct tpu_pwm_device *pwm = pwm_get_chip_data(_pwm); + struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); int ret; - ret = tpu_pwm_timer_start(pwm); + ret = tpu_pwm_timer_start(tpd); if (ret < 0) return ret; @@ -347,32 +373,64 @@ static int tpu_pwm_enable(struct pwm_chip *chip, struct pwm_device *_pwm) * To avoid running the timer when not strictly required, handle 0% and * 100% duty cycles as fixed levels and stop the timer. */ - if (pwm->duty == 0 || pwm->duty == pwm->period) { - tpu_pwm_set_pin(pwm, pwm->duty ? + if (tpd->duty == 0 || tpd->duty == tpd->period) { + tpu_pwm_set_pin(tpd, tpd->duty ? TPU_PIN_ACTIVE : TPU_PIN_INACTIVE); - tpu_pwm_timer_stop(pwm); + tpu_pwm_timer_stop(tpd); } return 0; } -static void tpu_pwm_disable(struct pwm_chip *chip, struct pwm_device *_pwm) +static void tpu_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { - struct tpu_pwm_device *pwm = pwm_get_chip_data(_pwm); + struct tpu_pwm_device *tpd = pwm_get_chip_data(pwm); /* The timer must be running to modify the pin output configuration. */ - tpu_pwm_timer_start(pwm); - tpu_pwm_set_pin(pwm, TPU_PIN_INACTIVE); - tpu_pwm_timer_stop(pwm); + tpu_pwm_timer_start(tpd); + tpu_pwm_set_pin(tpd, TPU_PIN_INACTIVE); + tpu_pwm_timer_stop(tpd); +} + +static int tpu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + int err; + bool enabled = pwm->state.enabled; + + if (state->polarity != pwm->state.polarity) { + if (enabled) { + tpu_pwm_disable(chip, pwm); + enabled = false; + } + + err = tpu_pwm_set_polarity(chip, pwm, state->polarity); + if (err) + return err; + } + + if (!state->enabled) { + if (enabled) + tpu_pwm_disable(chip, pwm); + + return 0; + } + + err = tpu_pwm_config(pwm->chip, pwm, + state->duty_cycle, state->period, enabled); + if (err) + return err; + + if (!enabled) + err = tpu_pwm_enable(chip, pwm); + + return err; } static const struct pwm_ops tpu_pwm_ops = { .request = tpu_pwm_request, .free = tpu_pwm_free, - .config = tpu_pwm_config, - .set_polarity = tpu_pwm_set_polarity, - .enable = tpu_pwm_enable, - .disable = tpu_pwm_disable, + .apply = tpu_pwm_apply, .owner = THIS_MODULE, }; @@ -398,10 +456,8 @@ static int tpu_probe(struct platform_device *pdev) return PTR_ERR(tpu->base); tpu->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(tpu->clk)) { - dev_err(&pdev->dev, "cannot get clock\n"); - return PTR_ERR(tpu->clk); - } + if (IS_ERR(tpu->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(tpu->clk), "Failed to get clock\n"); /* Initialize and register the device. */ platform_set_drvdata(pdev, tpu); @@ -410,25 +466,13 @@ static int tpu_probe(struct platform_device *pdev) tpu->chip.ops = &tpu_pwm_ops; tpu->chip.npwm = TPU_CHANNEL_MAX; - pm_runtime_enable(&pdev->dev); - - ret = pwmchip_add(&tpu->chip); - if (ret < 0) { - dev_err(&pdev->dev, "failed to register PWM chip\n"); - pm_runtime_disable(&pdev->dev); - return ret; - } - - return 0; -} - -static int tpu_remove(struct platform_device *pdev) -{ - struct tpu_device *tpu = platform_get_drvdata(pdev); - - pwmchip_remove(&tpu->chip); + ret = devm_pm_runtime_enable(&pdev->dev); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "Failed to enable runtime PM\n"); - pm_runtime_disable(&pdev->dev); + ret = devm_pwmchip_add(&pdev->dev, &tpu->chip); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "Failed to register PWM chip\n"); return 0; } @@ -447,7 +491,6 @@ MODULE_DEVICE_TABLE(of, tpu_of_table); static struct platform_driver tpu_driver = { .probe = tpu_probe, - .remove = tpu_remove, .driver = { .name = "renesas-tpu-pwm", .of_match_table = of_match_ptr(tpu_of_table), |