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path: root/drivers/pwm/pwm-bcm-kona.c
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Diffstat (limited to 'drivers/pwm/pwm-bcm-kona.c')
-rw-r--r--drivers/pwm/pwm-bcm-kona.c154
1 files changed, 74 insertions, 80 deletions
diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c
index 81da91df2529..022c078aae84 100644
--- a/drivers/pwm/pwm-bcm-kona.c
+++ b/drivers/pwm/pwm-bcm-kona.c
@@ -1,15 +1,5 @@
-/*
- * Copyright (C) 2014 Broadcom Corporation
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation version 2.
- *
- * This program is distributed "as is" WITHOUT ANY WARRANTY of any
- * kind, whether express or implied; without even the implied warranty
- * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2014 Broadcom Corporation
#include <linux/clk.h>
#include <linux/delay.h>
@@ -66,14 +56,13 @@
#define DUTY_CYCLE_HIGH_MAX 0x00ffffff
struct kona_pwmc {
- struct pwm_chip chip;
void __iomem *base;
struct clk *clk;
};
-static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *_chip)
+static inline struct kona_pwmc *to_kona_pwmc(struct pwm_chip *chip)
{
- return container_of(_chip, struct kona_pwmc, chip);
+ return pwmchip_get_drvdata(chip);
}
/*
@@ -109,10 +98,10 @@ static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan)
}
static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+ u64 duty_ns, u64 period_ns)
{
struct kona_pwmc *kp = to_kona_pwmc(chip);
- u64 val, div, rate;
+ u64 div, rate;
unsigned long prescale = PRESCALE_MIN, pc, dc;
unsigned int value, chan = pwm->hwpwm;
@@ -132,13 +121,11 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,
while (1) {
div = 1000000000;
div *= 1 + prescale;
- val = rate * period_ns;
- pc = div64_u64(val, div);
- val = rate * duty_ns;
- dc = div64_u64(val, div);
+ pc = mul_u64_u64_div_u64(rate, period_ns, div);
+ dc = mul_u64_u64_div_u64(rate, duty_ns, div);
/* If duty_ns or period_ns are not achievable then return */
- if (pc < PERIOD_COUNT_MIN || dc < DUTY_CYCLE_HIGH_MIN)
+ if (pc < PERIOD_COUNT_MIN)
return -EINVAL;
/* If pc and dc are in bounds, the calculation is done */
@@ -150,25 +137,18 @@ static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,
return -EINVAL;
}
- /*
- * Don't apply settings if disabled. The period and duty cycle are
- * always calculated above to ensure the new values are
- * validated immediately instead of on enable.
- */
- if (pwm_is_enabled(pwm)) {
- kona_pwmc_prepare_for_settings(kp, chan);
+ kona_pwmc_prepare_for_settings(kp, chan);
- value = readl(kp->base + PRESCALE_OFFSET);
- value &= ~PRESCALE_MASK(chan);
- value |= prescale << PRESCALE_SHIFT(chan);
- writel(value, kp->base + PRESCALE_OFFSET);
+ value = readl(kp->base + PRESCALE_OFFSET);
+ value &= ~PRESCALE_MASK(chan);
+ value |= prescale << PRESCALE_SHIFT(chan);
+ writel(value, kp->base + PRESCALE_OFFSET);
- writel(pc, kp->base + PERIOD_COUNT_OFFSET(chan));
+ writel(pc, kp->base + PERIOD_COUNT_OFFSET(chan));
- writel(dc, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));
+ writel(dc, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));
- kona_pwmc_apply_settings(kp, chan);
- }
+ kona_pwmc_apply_settings(kp, chan);
return 0;
}
@@ -183,7 +163,7 @@ static int kona_pwmc_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
ret = clk_prepare_enable(kp->clk);
if (ret < 0) {
- dev_err(chip->dev, "failed to enable clock: %d\n", ret);
+ dev_err(pwmchip_parent(chip), "failed to enable clock: %d\n", ret);
return ret;
}
@@ -212,14 +192,7 @@ static int kona_pwmc_enable(struct pwm_chip *chip, struct pwm_device *pwm)
ret = clk_prepare_enable(kp->clk);
if (ret < 0) {
- dev_err(chip->dev, "failed to enable clock: %d\n", ret);
- return ret;
- }
-
- ret = kona_pwmc_config(chip, pwm, pwm_get_duty_cycle(pwm),
- pwm_get_period(pwm));
- if (ret < 0) {
- clk_disable_unprepare(kp->clk);
+ dev_err(pwmchip_parent(chip), "failed to enable clock: %d\n", ret);
return ret;
}
@@ -248,37 +221,71 @@ static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm)
clk_disable_unprepare(kp->clk);
}
+static int kona_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int err;
+ struct kona_pwmc *kp = to_kona_pwmc(chip);
+ bool enabled = pwm->state.enabled;
+
+ if (state->polarity != pwm->state.polarity) {
+ if (enabled) {
+ kona_pwmc_disable(chip, pwm);
+ enabled = false;
+ }
+
+ err = kona_pwmc_set_polarity(chip, pwm, state->polarity);
+ if (err)
+ return err;
+
+ pwm->state.polarity = state->polarity;
+ }
+
+ if (!state->enabled) {
+ if (enabled)
+ kona_pwmc_disable(chip, pwm);
+ return 0;
+ } else if (!enabled) {
+ /*
+ * This is a bit special here, usually the PWM should only be
+ * enabled when duty and period are setup. But before this
+ * driver was converted to .apply it was done the other way
+ * around and so this behaviour was kept even though this might
+ * result in a glitch. This might be improvable by someone with
+ * hardware and/or documentation.
+ */
+ err = kona_pwmc_enable(chip, pwm);
+ if (err)
+ return err;
+ }
+
+ err = kona_pwmc_config(chip, pwm, state->duty_cycle, state->period);
+ if (err && !pwm->state.enabled)
+ clk_disable_unprepare(kp->clk);
+
+ return err;
+}
+
static const struct pwm_ops kona_pwm_ops = {
- .config = kona_pwmc_config,
- .set_polarity = kona_pwmc_set_polarity,
- .enable = kona_pwmc_enable,
- .disable = kona_pwmc_disable,
- .owner = THIS_MODULE,
+ .apply = kona_pwmc_apply,
};
static int kona_pwmc_probe(struct platform_device *pdev)
{
+ struct pwm_chip *chip;
struct kona_pwmc *kp;
- struct resource *res;
unsigned int chan;
unsigned int value = 0;
int ret = 0;
- kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);
- if (kp == NULL)
- return -ENOMEM;
-
- platform_set_drvdata(pdev, kp);
+ chip = devm_pwmchip_alloc(&pdev->dev, 6, sizeof(*kp));
+ if (IS_ERR(chip))
+ return PTR_ERR(chip);
+ kp = to_kona_pwmc(chip);
- kp->chip.dev = &pdev->dev;
- kp->chip.ops = &kona_pwm_ops;
- kp->chip.base = -1;
- kp->chip.npwm = 6;
- kp->chip.of_xlate = of_pwm_xlate_with_flags;
- kp->chip.of_pwm_n_cells = 3;
+ chip->ops = &kona_pwm_ops;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- kp->base = devm_ioremap_resource(&pdev->dev, res);
+ kp->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(kp->base))
return PTR_ERR(kp->base);
@@ -296,32 +303,20 @@ static int kona_pwmc_probe(struct platform_device *pdev)
}
/* Set push/pull for all channels */
- for (chan = 0; chan < kp->chip.npwm; chan++)
+ for (chan = 0; chan < chip->npwm; chan++)
value |= (1 << PWM_CONTROL_TYPE_SHIFT(chan));
writel(value, kp->base + PWM_CONTROL_OFFSET);
clk_disable_unprepare(kp->clk);
- ret = pwmchip_add_with_polarity(&kp->chip, PWM_POLARITY_INVERSED);
+ ret = devm_pwmchip_add(&pdev->dev, chip);
if (ret < 0)
dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
return ret;
}
-static int kona_pwmc_remove(struct platform_device *pdev)
-{
- struct kona_pwmc *kp = platform_get_drvdata(pdev);
- unsigned int chan;
-
- for (chan = 0; chan < kp->chip.npwm; chan++)
- if (pwm_is_enabled(&kp->chip.pwms[chan]))
- clk_disable_unprepare(kp->clk);
-
- return pwmchip_remove(&kp->chip);
-}
-
static const struct of_device_id bcm_kona_pwmc_dt[] = {
{ .compatible = "brcm,kona-pwm" },
{ },
@@ -334,7 +329,6 @@ static struct platform_driver kona_pwmc_driver = {
.of_match_table = bcm_kona_pwmc_dt,
},
.probe = kona_pwmc_probe,
- .remove = kona_pwmc_remove,
};
module_platform_driver(kona_pwmc_driver);