| Message ID | 1572279108-25916-3-git-send-email-fabrice.gasnier@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: stm32: add max clock rate | expand |
On Mon, 28 Oct 2019 17:11:48 +0100 Fabrice Gasnier <fabrice.gasnier@st.com> wrote: > Add new optional dt property to tune analog clock prescaler. > Driver looks for optional "st,max-clk-rate-hz", then computes > best approximation below that rate, using ADC internal prescaler. > > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> If the previous email I wrote on this got to anyone before I hit cancel, please ignore. Had completely failed to read the code correctly. Anyhow this seems fine to me, but given there are a lot of existing clk related bindings I'd like to give a little longer for Rob to have a chance to take a look at the binding. Give me a poke if I seem to have lost this in a week or so. Thanks, Jonathan > --- > drivers/iio/adc/stm32-adc-core.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c > index 20c626c..6537f4f 100644 > --- a/drivers/iio/adc/stm32-adc-core.c > +++ b/drivers/iio/adc/stm32-adc-core.c > @@ -79,6 +79,7 @@ struct stm32_adc_priv_cfg { > * @domain: irq domain reference > * @aclk: clock reference for the analog circuitry > * @bclk: bus clock common for all ADCs, depends on part used > + * @max_clk_rate: desired maximum clock rate > * @booster: booster supply reference > * @vdd: vdd supply reference > * @vdda: vdda analog supply reference > @@ -95,6 +96,7 @@ struct stm32_adc_priv { > struct irq_domain *domain; > struct clk *aclk; > struct clk *bclk; > + u32 max_clk_rate; > struct regulator *booster; > struct regulator *vdd; > struct regulator *vdda; > @@ -141,7 +143,7 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev, > } > > for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) { > - if ((rate / stm32f4_pclk_div[i]) <= priv->cfg->max_clk_rate_hz) > + if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate) > break; > } > if (i >= ARRAY_SIZE(stm32f4_pclk_div)) { > @@ -230,7 +232,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev, > if (ckmode) > continue; > > - if ((rate / div) <= priv->cfg->max_clk_rate_hz) > + if ((rate / div) <= priv->max_clk_rate) > goto out; > } > } > @@ -250,7 +252,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev, > if (!ckmode) > continue; > > - if ((rate / div) <= priv->cfg->max_clk_rate_hz) > + if ((rate / div) <= priv->max_clk_rate) > goto out; > } > > @@ -655,6 +657,7 @@ static int stm32_adc_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct device_node *np = pdev->dev.of_node; > struct resource *res; > + u32 max_rate; > int ret; > > if (!pdev->dev.of_node) > @@ -731,6 +734,13 @@ static int stm32_adc_probe(struct platform_device *pdev) > priv->common.vref_mv = ret / 1000; > dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv); > > + ret = of_property_read_u32(pdev->dev.of_node, "st,max-clk-rate-hz", > + &max_rate); > + if (!ret) > + priv->max_clk_rate = min(max_rate, priv->cfg->max_clk_rate_hz); > + else > + priv->max_clk_rate = priv->cfg->max_clk_rate_hz; > + > ret = priv->cfg->clk_sel(pdev, priv); > if (ret < 0) > goto err_hw_stop;
On Sun, 3 Nov 2019 12:30:42 +0000 Jonathan Cameron <jic23@kernel.org> wrote: > On Mon, 28 Oct 2019 17:11:48 +0100 > Fabrice Gasnier <fabrice.gasnier@st.com> wrote: > > > Add new optional dt property to tune analog clock prescaler. > > Driver looks for optional "st,max-clk-rate-hz", then computes > > best approximation below that rate, using ADC internal prescaler. > > > > Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> > If the previous email I wrote on this got to anyone before I hit > cancel, please ignore. Had completely failed to read the code correctly. > > Anyhow this seems fine to me, but given there are a lot of existing > clk related bindings I'd like to give a little longer for Rob to > have a chance to take a look at the binding. > > Give me a poke if I seem to have lost this in a week or so. Applied to the togreg branch of iio.git. Shortly to be pushed out as testing for the autobuilders to poke at it. Thanks, Jonathan > > Thanks, > > Jonathan > > > > > --- > > drivers/iio/adc/stm32-adc-core.c | 16 +++++++++++++--- > > 1 file changed, 13 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c > > index 20c626c..6537f4f 100644 > > --- a/drivers/iio/adc/stm32-adc-core.c > > +++ b/drivers/iio/adc/stm32-adc-core.c > > @@ -79,6 +79,7 @@ struct stm32_adc_priv_cfg { > > * @domain: irq domain reference > > * @aclk: clock reference for the analog circuitry > > * @bclk: bus clock common for all ADCs, depends on part used > > + * @max_clk_rate: desired maximum clock rate > > * @booster: booster supply reference > > * @vdd: vdd supply reference > > * @vdda: vdda analog supply reference > > @@ -95,6 +96,7 @@ struct stm32_adc_priv { > > struct irq_domain *domain; > > struct clk *aclk; > > struct clk *bclk; > > + u32 max_clk_rate; > > struct regulator *booster; > > struct regulator *vdd; > > struct regulator *vdda; > > @@ -141,7 +143,7 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev, > > } > > > > for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) { > > - if ((rate / stm32f4_pclk_div[i]) <= priv->cfg->max_clk_rate_hz) > > + if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate) > > break; > > } > > if (i >= ARRAY_SIZE(stm32f4_pclk_div)) { > > @@ -230,7 +232,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev, > > if (ckmode) > > continue; > > > > - if ((rate / div) <= priv->cfg->max_clk_rate_hz) > > + if ((rate / div) <= priv->max_clk_rate) > > goto out; > > } > > } > > @@ -250,7 +252,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev, > > if (!ckmode) > > continue; > > > > - if ((rate / div) <= priv->cfg->max_clk_rate_hz) > > + if ((rate / div) <= priv->max_clk_rate) > > goto out; > > } > > > > @@ -655,6 +657,7 @@ static int stm32_adc_probe(struct platform_device *pdev) > > struct device *dev = &pdev->dev; > > struct device_node *np = pdev->dev.of_node; > > struct resource *res; > > + u32 max_rate; > > int ret; > > > > if (!pdev->dev.of_node) > > @@ -731,6 +734,13 @@ static int stm32_adc_probe(struct platform_device *pdev) > > priv->common.vref_mv = ret / 1000; > > dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv); > > > > + ret = of_property_read_u32(pdev->dev.of_node, "st,max-clk-rate-hz", > > + &max_rate); > > + if (!ret) > > + priv->max_clk_rate = min(max_rate, priv->cfg->max_clk_rate_hz); > > + else > > + priv->max_clk_rate = priv->cfg->max_clk_rate_hz; > > + > > ret = priv->cfg->clk_sel(pdev, priv); > > if (ret < 0) > > goto err_hw_stop; >
diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c index 20c626c..6537f4f 100644 --- a/drivers/iio/adc/stm32-adc-core.c +++ b/drivers/iio/adc/stm32-adc-core.c @@ -79,6 +79,7 @@ struct stm32_adc_priv_cfg { * @domain: irq domain reference * @aclk: clock reference for the analog circuitry * @bclk: bus clock common for all ADCs, depends on part used + * @max_clk_rate: desired maximum clock rate * @booster: booster supply reference * @vdd: vdd supply reference * @vdda: vdda analog supply reference @@ -95,6 +96,7 @@ struct stm32_adc_priv { struct irq_domain *domain; struct clk *aclk; struct clk *bclk; + u32 max_clk_rate; struct regulator *booster; struct regulator *vdd; struct regulator *vdda; @@ -141,7 +143,7 @@ static int stm32f4_adc_clk_sel(struct platform_device *pdev, } for (i = 0; i < ARRAY_SIZE(stm32f4_pclk_div); i++) { - if ((rate / stm32f4_pclk_div[i]) <= priv->cfg->max_clk_rate_hz) + if ((rate / stm32f4_pclk_div[i]) <= priv->max_clk_rate) break; } if (i >= ARRAY_SIZE(stm32f4_pclk_div)) { @@ -230,7 +232,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev, if (ckmode) continue; - if ((rate / div) <= priv->cfg->max_clk_rate_hz) + if ((rate / div) <= priv->max_clk_rate) goto out; } } @@ -250,7 +252,7 @@ static int stm32h7_adc_clk_sel(struct platform_device *pdev, if (!ckmode) continue; - if ((rate / div) <= priv->cfg->max_clk_rate_hz) + if ((rate / div) <= priv->max_clk_rate) goto out; } @@ -655,6 +657,7 @@ static int stm32_adc_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct device_node *np = pdev->dev.of_node; struct resource *res; + u32 max_rate; int ret; if (!pdev->dev.of_node) @@ -731,6 +734,13 @@ static int stm32_adc_probe(struct platform_device *pdev) priv->common.vref_mv = ret / 1000; dev_dbg(&pdev->dev, "vref+=%dmV\n", priv->common.vref_mv); + ret = of_property_read_u32(pdev->dev.of_node, "st,max-clk-rate-hz", + &max_rate); + if (!ret) + priv->max_clk_rate = min(max_rate, priv->cfg->max_clk_rate_hz); + else + priv->max_clk_rate = priv->cfg->max_clk_rate_hz; + ret = priv->cfg->clk_sel(pdev, priv); if (ret < 0) goto err_hw_stop;
Add new optional dt property to tune analog clock prescaler. Driver looks for optional "st,max-clk-rate-hz", then computes best approximation below that rate, using ADC internal prescaler. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> --- drivers/iio/adc/stm32-adc-core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)