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pwm: ab8500: Fix register offset calculation to not depend on probe order

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The assumption that lead to commit 5e5da1e9fb ("pwm: ab8500:
Explicitly allocate pwm chip base dynamically") was wrong: The
pwm-ab8500 devices are not directly instantiated from device tree, but
from the ab8500 mfd driver. So the pdev->id isn't -1, but a number
between 1 and 3. Now that pwmchip ids are always allocated dynamically,
this cannot easily be reverted.

Introduce a new member in the driver data struct that tracks the
hardware id and use this to calculate the register offset.

Side-note: Using chip->base to calculate the offset was never robust
because if there was already a PWM with id 1 at the time ab8500-pwm.1
was probed, the associated pwmchip would get assigned chip->base = 2 (or
something bigger).

Fixes: 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip base dynamically")
Fixes: 6173f8f4ed ("pwm: Move AB8500 PWM driver to PWM framework")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Uwe Kleine-König 2021-07-05 18:55:10 +02:00 committed by Thierry Reding
parent 52eaba4ced
commit eb41f33458
1 changed files with 14 additions and 3 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

17
drivers/pwm/pwm-ab8500.c
View file

@ -22,14 +22,21 @@
struct ab8500_pwm_chip { struct ab8500_pwm_chip {
struct pwm_chip chip; struct pwm_chip chip;
unsigned int hwid;
}; };
static struct ab8500_pwm_chip *ab8500_pwm_from_chip(struct pwm_chip *chip)
{
return container_of(chip, struct ab8500_pwm_chip, chip);
}
static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *state) const struct pwm_state *state)
{ {
int ret; int ret;
u8 reg; u8 reg;
unsigned int higher_val, lower_val; unsigned int higher_val, lower_val;
struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
if (state->polarity != PWM_POLARITY_NORMAL) if (state->polarity != PWM_POLARITY_NORMAL)
return -EINVAL; return -EINVAL;
@ -37,7 +44,7 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
if (!state->enabled) { if (!state->enabled) {
ret = abx500_mask_and_set_register_interruptible(chip->dev, ret = abx500_mask_and_set_register_interruptible(chip->dev,
AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
1 << (chip->base - 1), 0); 1 << ab8500->hwid, 0);
if (ret < 0) if (ret < 0)
dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
@ -56,7 +63,7 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
*/ */
higher_val = ((state->duty_cycle & 0x0300) >> 8); higher_val = ((state->duty_cycle & 0x0300) >> 8);
reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2); reg = AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2);
ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC, ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
reg, (u8)lower_val); reg, (u8)lower_val);
@ -70,7 +77,7 @@ static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
ret = abx500_mask_and_set_register_interruptible(chip->dev, ret = abx500_mask_and_set_register_interruptible(chip->dev,
AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
1 << (chip->base - 1), 1 << (chip->base - 1)); 1 << ab8500->hwid, 1 << ab8500->hwid);
if (ret < 0) if (ret < 0)
dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n", dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
pwm->label, ret); pwm->label, ret);
@ -88,6 +95,9 @@ static int ab8500_pwm_probe(struct platform_device *pdev)
struct ab8500_pwm_chip *ab8500; struct ab8500_pwm_chip *ab8500;
int err; int err;
if (pdev->id < 1 || pdev->id > 31)
return dev_err_probe(&pdev->dev, EINVAL, "Invalid device id %d\n", pdev->id);
/* /*
* Nothing to be done in probe, this is required to get the * Nothing to be done in probe, this is required to get the
* device which is required for ab8500 read and write * device which is required for ab8500 read and write
@ -99,6 +109,7 @@ static int ab8500_pwm_probe(struct platform_device *pdev)
ab8500->chip.dev = &pdev->dev; ab8500->chip.dev = &pdev->dev;
ab8500->chip.ops = &ab8500_pwm_ops; ab8500->chip.ops = &ab8500_pwm_ops;
ab8500->chip.npwm = 1; ab8500->chip.npwm = 1;
ab8500->hwid = pdev->id - 1;
err = pwmchip_add(&ab8500->chip); err = pwmchip_add(&ab8500->chip);
if (err < 0) if (err < 0)