| Message ID | 1485726855-16236-8-git-send-email-lukma@denx.de |
|---|---|
| State | Accepted |
| Headers | show |
On Sun, 29 Jan 2017 22:54:11 +0100 Lukasz Majewski <lukma@denx.de> wrote: > This commit provides apply() callback implementation for i.MX's PWMv2. > > Suggested-by: Stefan Agner <stefan@agner.ch> > Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com> > Signed-off-by: Lukasz Majewski <l.majewski@majess.pl> > Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> > --- > Changes for v5: > - Modify ->apply() function to avoid unbalanced clock enabling/disabling > - Fix preventing iMX7 from hanging > > Changes for v4: > - Avoid recalculation of PWM parameters when disabling PWM signal > - Unconditionally call clk_prepare_enable(imx->clk_per) and > clk_disable_unprepare(imx->clk_per) > > Changes for v3: > - Remove ipg clock enable/disable functions > > Changes for v2: > - None > --- > drivers/pwm/pwm-imx.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 68 insertions(+) > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > index 60cdc5c..fdaa11b 100644 > --- a/drivers/pwm/pwm-imx.c > +++ b/drivers/pwm/pwm-imx.c > @@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip, > return ret; > } > > +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm, > + struct pwm_state *state) > +{ > + unsigned long period_cycles, duty_cycles, prescale; > + struct imx_chip *imx = to_imx_chip(chip); > + struct pwm_state cstate; > + unsigned long long c; > + int ret; > + > + pwm_get_state(pwm, &cstate); > + > + if (state->enabled) { > + c = clk_get_rate(imx->clk_per); > + c *= state->period; > + > + do_div(c, 1000000000); > + period_cycles = c; > + > + prescale = period_cycles / 0x10000 + 1; > + > + period_cycles /= prescale; > + c = (unsigned long long)period_cycles * state->duty_cycle; > + do_div(c, state->period); > + duty_cycles = c; > + > + /* > + * according to imx pwm RM, the real period value should be > + * PERIOD value in PWMPR plus 2. > + */ > + if (period_cycles > 2) > + period_cycles -= 2; > + else > + period_cycles = 0; > + > + /* > + * Wait for a free FIFO slot if the PWM is already enabled, and > + * flush the FIFO if the PWM was disabled and is about to be > + * enabled. > + */ > + if (cstate.enabled) { > + imx_pwm_wait_fifo_slot(chip, pwm); > + } else if (state->enabled) { Should just be } else { since we're already in the 'if (state->enabled)' block (see above). I see that Thierry already applied the series, so, just for the record, with this fixed, the whole series is Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> Thanks, Boris > + ret = clk_prepare_enable(imx->clk_per); > + if (ret) > + return ret; > + > + imx_pwm_sw_reset(chip); > + } > + > + writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); > + writel(period_cycles, imx->mmio_base + MX3_PWMPR); > + > + writel(MX3_PWMCR_PRESCALER(prescale) | > + MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | > + MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH | > + MX3_PWMCR_EN, > + imx->mmio_base + MX3_PWMCR); > + > + } else if (cstate.enabled) { > + writel(0, imx->mmio_base + MX3_PWMCR); > + > + clk_disable_unprepare(imx->clk_per); > + } > + > + return 0; > +} -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Jan 30, 2017 at 08:49:14AM +0100, Boris Brezillon wrote: > On Sun, 29 Jan 2017 22:54:11 +0100 > Lukasz Majewski <lukma@denx.de> wrote: > > > This commit provides apply() callback implementation for i.MX's PWMv2. > > > > Suggested-by: Stefan Agner <stefan@agner.ch> > > Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > Signed-off-by: Lukasz Majewski <l.majewski@majess.pl> > > Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > --- > > Changes for v5: > > - Modify ->apply() function to avoid unbalanced clock enabling/disabling > > - Fix preventing iMX7 from hanging > > > > Changes for v4: > > - Avoid recalculation of PWM parameters when disabling PWM signal > > - Unconditionally call clk_prepare_enable(imx->clk_per) and > > clk_disable_unprepare(imx->clk_per) > > > > Changes for v3: > > - Remove ipg clock enable/disable functions > > > > Changes for v2: > > - None > > --- > > drivers/pwm/pwm-imx.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 68 insertions(+) > > > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > > index 60cdc5c..fdaa11b 100644 > > --- a/drivers/pwm/pwm-imx.c > > +++ b/drivers/pwm/pwm-imx.c > > @@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip, > > return ret; > > } > > > > +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm, > > + struct pwm_state *state) > > +{ > > + unsigned long period_cycles, duty_cycles, prescale; > > + struct imx_chip *imx = to_imx_chip(chip); > > + struct pwm_state cstate; > > + unsigned long long c; > > + int ret; > > + > > + pwm_get_state(pwm, &cstate); > > + > > + if (state->enabled) { > > + c = clk_get_rate(imx->clk_per); > > + c *= state->period; > > + > > + do_div(c, 1000000000); > > + period_cycles = c; > > + > > + prescale = period_cycles / 0x10000 + 1; > > + > > + period_cycles /= prescale; > > + c = (unsigned long long)period_cycles * state->duty_cycle; > > + do_div(c, state->period); > > + duty_cycles = c; > > + > > + /* > > + * according to imx pwm RM, the real period value should be > > + * PERIOD value in PWMPR plus 2. > > + */ > > + if (period_cycles > 2) > > + period_cycles -= 2; > > + else > > + period_cycles = 0; > > + > > + /* > > + * Wait for a free FIFO slot if the PWM is already enabled, and > > + * flush the FIFO if the PWM was disabled and is about to be > > + * enabled. > > + */ > > + if (cstate.enabled) { > > + imx_pwm_wait_fifo_slot(chip, pwm); > > + } else if (state->enabled) { > > Should just be > > } else { > > since we're already in the 'if (state->enabled)' block (see above). > > I see that Thierry already applied the series, so, just for the record, > with this fixed, the whole series is > > Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com> I haven't gotten to that patch yet because I need to manually apply a bunch of these because of the const pwm_ops patch. I'll apply the change you mentioned and will add your R-b tag. Thanks, Thierry
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c index 60cdc5c..fdaa11b 100644 --- a/drivers/pwm/pwm-imx.c +++ b/drivers/pwm/pwm-imx.c @@ -249,6 +249,73 @@ static int imx_pwm_config(struct pwm_chip *chip, return ret; } +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + unsigned long period_cycles, duty_cycles, prescale; + struct imx_chip *imx = to_imx_chip(chip); + struct pwm_state cstate; + unsigned long long c; + int ret; + + pwm_get_state(pwm, &cstate); + + if (state->enabled) { + c = clk_get_rate(imx->clk_per); + c *= state->period; + + do_div(c, 1000000000); + period_cycles = c; + + prescale = period_cycles / 0x10000 + 1; + + period_cycles /= prescale; + c = (unsigned long long)period_cycles * state->duty_cycle; + do_div(c, state->period); + duty_cycles = c; + + /* + * according to imx pwm RM, the real period value should be + * PERIOD value in PWMPR plus 2. + */ + if (period_cycles > 2) + period_cycles -= 2; + else + period_cycles = 0; + + /* + * Wait for a free FIFO slot if the PWM is already enabled, and + * flush the FIFO if the PWM was disabled and is about to be + * enabled. + */ + if (cstate.enabled) { + imx_pwm_wait_fifo_slot(chip, pwm); + } else if (state->enabled) { + ret = clk_prepare_enable(imx->clk_per); + if (ret) + return ret; + + imx_pwm_sw_reset(chip); + } + + writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); + writel(period_cycles, imx->mmio_base + MX3_PWMPR); + + writel(MX3_PWMCR_PRESCALER(prescale) | + MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | + MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH | + MX3_PWMCR_EN, + imx->mmio_base + MX3_PWMCR); + + } else if (cstate.enabled) { + writel(0, imx->mmio_base + MX3_PWMCR); + + clk_disable_unprepare(imx->clk_per); + } + + return 0; +} + static int imx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct imx_chip *imx = to_imx_chip(chip); @@ -280,6 +347,7 @@ static struct pwm_ops imx_pwm_ops_v1 = { }; static struct pwm_ops imx_pwm_ops_v2 = { + .apply = imx_pwm_apply_v2, .enable = imx_pwm_enable, .disable = imx_pwm_disable, .config = imx_pwm_config,