From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Tue, 14 Jun 2016 11:13:14 +0200 Subject: [PATCH v3 06/14] pwm: rockchip: Add support for atomic update In-Reply-To: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> References: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> Message-ID: <1465895602-31008-7-git-send-email-boris.brezillon@free-electrons.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Implement the ->apply() function to add support for atomic update. Signed-off-by: Boris Brezillon Tested-by: Heiko Stuebner Reviewed-by: Brian Norris Tested-by: Brian Norris --- drivers/pwm/pwm-rockchip.c | 84 ++++++++++++++++++++++++---------------------- 1 file changed, 43 insertions(+), 41 deletions(-) diff --git a/drivers/pwm/pwm-rockchip.c b/drivers/pwm/pwm-rockchip.c index dd8ca86..ef89df1 100644 --- a/drivers/pwm/pwm-rockchip.c +++ b/drivers/pwm/pwm-rockchip.c @@ -47,10 +47,12 @@ struct rockchip_pwm_regs { struct rockchip_pwm_data { struct rockchip_pwm_regs regs; unsigned int prescaler; + bool supports_polarity; const struct pwm_ops *ops; void (*set_enable)(struct pwm_chip *chip, - struct pwm_device *pwm, bool enable); + struct pwm_device *pwm, bool enable, + enum pwm_polarity polarity); void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state); }; @@ -61,7 +63,8 @@ static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c) } static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, - struct pwm_device *pwm, bool enable) + struct pwm_device *pwm, bool enable, + enum pwm_polarity polarity) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN; @@ -91,14 +94,15 @@ static void rockchip_pwm_get_state_v1(struct pwm_chip *chip, } static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, - struct pwm_device *pwm, bool enable) + struct pwm_device *pwm, bool enable, + enum pwm_polarity polarity) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | PWM_CONTINUOUS; u32 val; - if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED) + if (polarity == PWM_POLARITY_INVERSED) enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE; else enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE; @@ -166,7 +170,6 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); unsigned long period, duty; u64 clk_rate, div; - int ret; clk_rate = clk_get_rate(pc->clk); @@ -182,69 +185,66 @@ static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, div = clk_rate * duty_ns; duty = DIV_ROUND_CLOSEST_ULL(div, pc->data->prescaler * NSEC_PER_SEC); - ret = clk_enable(pc->clk); - if (ret) - return ret; - writel(period, pc->base + pc->data->regs.period); writel(duty, pc->base + pc->data->regs.duty); - writel(0, pc->base + pc->data->regs.cntr); - - clk_disable(pc->clk); - - return 0; -} - -static int rockchip_pwm_set_polarity(struct pwm_chip *chip, - struct pwm_device *pwm, - enum pwm_polarity polarity) -{ - /* - * No action needed here because pwm->polarity will be set by the core - * and the core will only change polarity when the PWM is not enabled. - * We'll handle things in set_enable(). - */ return 0; } -static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +static int rockchip_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + struct pwm_state curstate; + bool enabled; int ret; + pwm_get_state(pwm, &curstate); + enabled = curstate.enabled; + ret = clk_enable(pc->clk); if (ret) return ret; - pc->data->set_enable(chip, pwm, true); + if (state->polarity != curstate.polarity && enabled) { + pc->data->set_enable(chip, pwm, false, state->polarity); + enabled = false; + } - return 0; -} + ret = rockchip_pwm_config(chip, pwm, state->duty_cycle, state->period); + if (ret) { + if (enabled != curstate.enabled) + pc->data->set_enable(chip, pwm, !enabled, + state->polarity); -static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); + goto out; + } + + if (state->enabled != enabled) + pc->data->set_enable(chip, pwm, state->enabled, + state->polarity); - pc->data->set_enable(chip, pwm, false); + /* + * Update the state with the real hardware, which can differ a bit + * because of period/duty_cycle approximation. + */ + rockchip_pwm_get_state(chip, pwm, state); +out: clk_disable(pc->clk); + + return ret; } static const struct pwm_ops rockchip_pwm_ops_v1 = { .get_state = rockchip_pwm_get_state, - .config = rockchip_pwm_config, - .enable = rockchip_pwm_enable, - .disable = rockchip_pwm_disable, + .apply = rockchip_pwm_apply, .owner = THIS_MODULE, }; static const struct pwm_ops rockchip_pwm_ops_v2 = { .get_state = rockchip_pwm_get_state, - .config = rockchip_pwm_config, - .set_polarity = rockchip_pwm_set_polarity, - .enable = rockchip_pwm_enable, - .disable = rockchip_pwm_disable, + .apply = rockchip_pwm_apply, .owner = THIS_MODULE, }; @@ -269,6 +269,7 @@ static const struct rockchip_pwm_data pwm_data_v2 = { .ctrl = 0x0c, }, .prescaler = 1, + .supports_polarity = true, .ops = &rockchip_pwm_ops_v2, .set_enable = rockchip_pwm_set_enable_v2, .get_state = rockchip_pwm_get_state_v2, @@ -282,6 +283,7 @@ static const struct rockchip_pwm_data pwm_data_vop = { .ctrl = 0x00, }, .prescaler = 1, + .supports_polarity = true, .ops = &rockchip_pwm_ops_v2, .set_enable = rockchip_pwm_set_enable_v2, .get_state = rockchip_pwm_get_state_v2, @@ -331,7 +333,7 @@ static int rockchip_pwm_probe(struct platform_device *pdev) pc->chip.base = -1; pc->chip.npwm = 1; - if (pc->data->ops->set_polarity) { + if (pc->data->supports_polarity) { pc->chip.of_xlate = of_pwm_xlate_with_flags; pc->chip.of_pwm_n_cells = 3; } -- 2.7.4