This is a note to let you know that I've just added the patch titled pwm: ab8500: Fix register offset calculation to not depend on probe order to the 5.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: pwm-ab8500-fix-register-offset-calculation-to-not-depend-on-probe-order.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From eb41f334589d66b9da6f2b1acf7963ef8ca8d94e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@xxxxxxxxxxxxxx> Date: Mon, 5 Jul 2021 18:55:10 +0200 Subject: pwm: ab8500: Fix register offset calculation to not depend on probe order MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> commit eb41f334589d66b9da6f2b1acf7963ef8ca8d94e upstream. The assumption that lead to commit 5e5da1e9fbee ("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: 5e5da1e9fbee ("pwm: ab8500: Explicitly allocate pwm chip base dynamically") Fixes: 6173f8f4ed9c ("pwm: Move AB8500 PWM driver to PWM framework") Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pwm/pwm-ab8500.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) --- a/drivers/pwm/pwm-ab8500.c +++ b/drivers/pwm/pwm-ab8500.c @@ -22,14 +22,21 @@ struct ab8500_pwm_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, const struct pwm_state *state) { int ret; u8 reg; unsigned int higher_val, lower_val; + struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip); if (state->polarity != PWM_POLARITY_NORMAL) return -EINVAL; @@ -37,7 +44,7 @@ static int ab8500_pwm_apply(struct pwm_c if (!state->enabled) { ret = abx500_mask_and_set_register_interruptible(chip->dev, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, - 1 << (chip->base - 1), 0); + 1 << ab8500->hwid, 0); if (ret < 0) dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n", @@ -56,7 +63,7 @@ static int ab8500_pwm_apply(struct pwm_c */ 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, reg, (u8)lower_val); @@ -70,7 +77,7 @@ static int ab8500_pwm_apply(struct pwm_c ret = abx500_mask_and_set_register_interruptible(chip->dev, AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG, - 1 << (chip->base - 1), 1 << (chip->base - 1)); + 1 << ab8500->hwid, 1 << ab8500->hwid); if (ret < 0) dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n", pwm->label, ret); @@ -88,6 +95,9 @@ static int ab8500_pwm_probe(struct platf struct ab8500_pwm_chip *ab8500; 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 * device which is required for ab8500 read and write @@ -99,6 +109,7 @@ static int ab8500_pwm_probe(struct platf ab8500->chip.dev = &pdev->dev; ab8500->chip.ops = &ab8500_pwm_ops; ab8500->chip.npwm = 1; + ab8500->hwid = pdev->id - 1; err = pwmchip_add(&ab8500->chip); if (err < 0) Patches currently in stable-queue which might be from u.kleine-koenig@xxxxxxxxxxxxxx are queue-5.14/pwm-mxs-don-t-modify-hw-state-in-.probe-after-the-pwm-chip-was-registered.patch queue-5.14/pwm-lpc32xx-don-t-modify-hw-state-in-.probe-after-the-pwm-chip-was-registered.patch queue-5.14/pwm-ab8500-fix-register-offset-calculation-to-not-depend-on-probe-order.patch