| Message ID | de316385a84e079d3b23891e61c959094b9fa7e5.1547781007.git.ryder.lee@mediatek.com |
|---|---|
| State | Rejected |
| Headers | show |
| Series | [v1,1/5] pwm: mediatek: add a property "mediatek,num-pwms" | expand |
Hello, On Fri, Jan 18, 2019 at 11:24:41AM +0800, Ryder Lee wrote: > This adds a property "mediatek,num-pwms" to avoid having an endless > list of compatibles with no differences for the same driver. > > Thus, the driver should have backwards compatibility to older DTs. I still think Thierry should bless "num-pwms" without vendor prefix. > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > --- > Changes since v1: add some checks for backwards compatibility. > --- > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > index eb6674c..81b7e5e 100644 > --- a/drivers/pwm/pwm-mediatek.c > +++ b/drivers/pwm/pwm-mediatek.c > @@ -55,7 +55,7 @@ enum { > }; > > struct mtk_pwm_platform_data { Unrelated to this patch: This name is bad. This struct is not used as platform_data and so should better be named mtk_pwm_of_data. While at criticizing existing stuff: I'd prefer pwm_mediatek as common prefix to match the filename. > - unsigned int num_pwms; > + unsigned int num_pwms; /* it should not be used in the future SoCs */ I'd drop this comment in favour of a runtime warning. > bool pwm45_fixup; > bool has_clks; > }; > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > static int mtk_pwm_probe(struct platform_device *pdev) > { > - const struct mtk_pwm_platform_data *data; > + struct device_node *np = pdev->dev.of_node; > struct mtk_pwm_chip *pc; > struct resource *res; > - unsigned int i; > + unsigned int i, num_pwms; > int ret; > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > if (!pc) > return -ENOMEM; > > - data = of_device_get_match_data(&pdev->dev); > - if (data == NULL) > - return -EINVAL; > - pc->soc = data; > + pc->soc = of_device_get_match_data(&pdev->dev); This might return NULL which ... > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > pc->regs = devm_ioremap_resource(&pdev->dev, res); > if (IS_ERR(pc->regs)) > return PTR_ERR(pc->regs); > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > + /* Check if we have set 'num-pwms' in DTs. */ > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > + if (ret < 0) { > + /* If no, fallback to use SoC data for backwards compatibility. */ > + if (pc->soc->num_pwms) { ... here then results in a NULL pointer dereference. I think you want if (pc->soc) here. > + num_pwms = pc->soc->num_pwms; > + } else { > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); > + return ret; > + } > + } > + > + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { > pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); > if (IS_ERR(pc->clks[i])) { > dev_err(&pdev->dev, "clock: %s fail: %ld\n", > @@ -260,7 +269,7 @@ static int mtk_pwm_probe(struct platform_device *pdev) > pc->chip.dev = &pdev->dev; > pc->chip.ops = &mtk_pwm_ops; > pc->chip.base = -1; > - pc->chip.npwm = data->num_pwms; > + pc->chip.npwm = num_pwms; > > ret = pwmchip_add(&pc->chip); > if (ret < 0) { Best regards Uwe
Hello, just realized another issue while looking up a driver detail ... On Fri, Jan 18, 2019 at 11:24:41AM +0800, Ryder Lee wrote: > This adds a property "mediatek,num-pwms" to avoid having an endless > list of compatibles with no differences for the same driver. > > Thus, the driver should have backwards compatibility to older DTs. > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > --- > Changes since v1: add some checks for backwards compatibility. > --- > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > index eb6674c..81b7e5e 100644 > --- a/drivers/pwm/pwm-mediatek.c > +++ b/drivers/pwm/pwm-mediatek.c > @@ -55,7 +55,7 @@ enum { > }; > > struct mtk_pwm_platform_data { > - unsigned int num_pwms; > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > bool pwm45_fixup; > bool has_clks; > }; > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > static int mtk_pwm_probe(struct platform_device *pdev) > { > - const struct mtk_pwm_platform_data *data; > + struct device_node *np = pdev->dev.of_node; > struct mtk_pwm_chip *pc; > struct resource *res; > - unsigned int i; > + unsigned int i, num_pwms; > int ret; > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > if (!pc) > return -ENOMEM; > > - data = of_device_get_match_data(&pdev->dev); > - if (data == NULL) > - return -EINVAL; > - pc->soc = data; > + pc->soc = of_device_get_match_data(&pdev->dev); > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > pc->regs = devm_ioremap_resource(&pdev->dev, res); > if (IS_ERR(pc->regs)) > return PTR_ERR(pc->regs); > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > + /* Check if we have set 'num-pwms' in DTs. */ > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > + if (ret < 0) { > + /* If no, fallback to use SoC data for backwards compatibility. */ > + if (pc->soc->num_pwms) { > + num_pwms = pc->soc->num_pwms; > + } else { > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); > + return ret; > + } > + } > + > + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { > pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); If a dt contains mediatek,num-pwms = <17>; you're accessing pc->clks[18] which is an out-of-bounds access, so better check the limit or allocate the clks array dynamically. Best regards Uwe
On 18/01/2019 04:24, Ryder Lee wrote: > This adds a property "mediatek,num-pwms" to avoid having an endless > list of compatibles with no differences for the same driver. > > Thus, the driver should have backwards compatibility to older DTs. > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > --- > Changes since v1: add some checks for backwards compatibility. > --- > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > 1 file changed, 18 insertions(+), 9 deletions(-) > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > index eb6674c..81b7e5e 100644 > --- a/drivers/pwm/pwm-mediatek.c > +++ b/drivers/pwm/pwm-mediatek.c > @@ -55,7 +55,7 @@ enum { > }; > > struct mtk_pwm_platform_data { > - unsigned int num_pwms; > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > bool pwm45_fixup; > bool has_clks; > }; > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > static int mtk_pwm_probe(struct platform_device *pdev) > { > - const struct mtk_pwm_platform_data *data; > + struct device_node *np = pdev->dev.of_node; > struct mtk_pwm_chip *pc; > struct resource *res; > - unsigned int i; > + unsigned int i, num_pwms; > int ret; > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > if (!pc) > return -ENOMEM; > > - data = of_device_get_match_data(&pdev->dev); > - if (data == NULL) > - return -EINVAL; > - pc->soc = data; > + pc->soc = of_device_get_match_data(&pdev->dev); > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > pc->regs = devm_ioremap_resource(&pdev->dev, res); > if (IS_ERR(pc->regs)) > return PTR_ERR(pc->regs); > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > + /* Check if we have set 'num-pwms' in DTs. */ > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > + if (ret < 0) { > + /* If no, fallback to use SoC data for backwards compatibility. */ > + if (pc->soc->num_pwms) { > + num_pwms = pc->soc->num_pwms; Maybe that's bike shedding, but I think it would be better to carve out the num_pwms from the mtk_pwm_platform_data and check against the compatible here. With a expressive comment it will help other driver developers to not start adding num_pwms in the platform data in their first attempt. Regards, Matthias > + } else { > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); > + return ret; > + } > + } > + > + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { > pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); > if (IS_ERR(pc->clks[i])) { > dev_err(&pdev->dev, "clock: %s fail: %ld\n", > @@ -260,7 +269,7 @@ static int mtk_pwm_probe(struct platform_device *pdev) > pc->chip.dev = &pdev->dev; > pc->chip.ops = &mtk_pwm_ops; > pc->chip.base = -1; > - pc->chip.npwm = data->num_pwms; > + pc->chip.npwm = num_pwms; > > ret = pwmchip_add(&pc->chip); > if (ret < 0) { >
On Fri, 2019-01-18 at 08:59 +0100, Uwe Kleine-König wrote: > Hello, > > On Fri, Jan 18, 2019 at 11:24:41AM +0800, Ryder Lee wrote: > > This adds a property "mediatek,num-pwms" to avoid having an endless > > list of compatibles with no differences for the same driver. > > > > Thus, the driver should have backwards compatibility to older DTs. > > I still think Thierry should bless "num-pwms" without vendor prefix. Okay. > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > --- > > Changes since v1: add some checks for backwards compatibility. > > --- > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > index eb6674c..81b7e5e 100644 > > --- a/drivers/pwm/pwm-mediatek.c > > +++ b/drivers/pwm/pwm-mediatek.c > > @@ -55,7 +55,7 @@ enum { > > }; > > > > struct mtk_pwm_platform_data { > > Unrelated to this patch: This name is bad. This struct is not used as > platform_data and so should better be named mtk_pwm_of_data. While at > criticizing existing stuff: I'd prefer pwm_mediatek as common prefix to > match the filename. I think we can take care about that in another patch. > > - unsigned int num_pwms; > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > I'd drop this comment in favour of a runtime warning. Sorry, I can't get you here. > > bool pwm45_fixup; > > bool has_clks; > > }; > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > { > > - const struct mtk_pwm_platform_data *data; > > + struct device_node *np = pdev->dev.of_node; > > struct mtk_pwm_chip *pc; > > struct resource *res; > > - unsigned int i; > > + unsigned int i, num_pwms; > > int ret; > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > if (!pc) > > return -ENOMEM; > > > > - data = of_device_get_match_data(&pdev->dev); > > - if (data == NULL) > > - return -EINVAL; > > - pc->soc = data; > > + pc->soc = of_device_get_match_data(&pdev->dev); > > This might return NULL which ... The only way to call probe() is to match an entry in mtk_pwm_of_match[], so match cannot be NULL. > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > pc->regs = devm_ioremap_resource(&pdev->dev, res); > > if (IS_ERR(pc->regs)) > > return PTR_ERR(pc->regs); > > > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > > + /* Check if we have set 'num-pwms' in DTs. */ > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > + if (ret < 0) { > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > + if (pc->soc->num_pwms) { > > ... here then results in a NULL pointer dereference. I think you want So we have no chance to get a NULL pointer, right? > if (pc->soc) > > here. > > > + num_pwms = pc->soc->num_pwms; > > + } else { > > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); > > + return ret; > > + } > > + } > > + > > + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { > > pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); > > if (IS_ERR(pc->clks[i])) { > > dev_err(&pdev->dev, "clock: %s fail: %ld\n", > > @@ -260,7 +269,7 @@ static int mtk_pwm_probe(struct platform_device *pdev) > > pc->chip.dev = &pdev->dev; > > pc->chip.ops = &mtk_pwm_ops; > > pc->chip.base = -1; > > - pc->chip.npwm = data->num_pwms; > > + pc->chip.npwm = num_pwms; > > > > ret = pwmchip_add(&pc->chip); > > if (ret < 0) { > > Best regards > Uwe >
On Fri, 2019-01-18 at 09:05 +0100, Uwe Kleine-König wrote: > Hello, > > just realized another issue while looking up a driver detail ... > > On Fri, Jan 18, 2019 at 11:24:41AM +0800, Ryder Lee wrote: > > This adds a property "mediatek,num-pwms" to avoid having an endless > > list of compatibles with no differences for the same driver. > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > --- > > Changes since v1: add some checks for backwards compatibility. > > --- > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > index eb6674c..81b7e5e 100644 > > --- a/drivers/pwm/pwm-mediatek.c > > +++ b/drivers/pwm/pwm-mediatek.c > > @@ -55,7 +55,7 @@ enum { > > }; > > > > struct mtk_pwm_platform_data { > > - unsigned int num_pwms; > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > bool pwm45_fixup; > > bool has_clks; > > }; > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > { > > - const struct mtk_pwm_platform_data *data; > > + struct device_node *np = pdev->dev.of_node; > > struct mtk_pwm_chip *pc; > > struct resource *res; > > - unsigned int i; > > + unsigned int i, num_pwms; > > int ret; > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > if (!pc) > > return -ENOMEM; > > > > - data = of_device_get_match_data(&pdev->dev); > > - if (data == NULL) > > - return -EINVAL; > > - pc->soc = data; > > + pc->soc = of_device_get_match_data(&pdev->dev); > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > pc->regs = devm_ioremap_resource(&pdev->dev, res); > > if (IS_ERR(pc->regs)) > > return PTR_ERR(pc->regs); > > > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > > + /* Check if we have set 'num-pwms' in DTs. */ > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > + if (ret < 0) { > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > + if (pc->soc->num_pwms) { > > + num_pwms = pc->soc->num_pwms; > > + } else { > > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); > > + return ret; > > + } > > + } > > + > > + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { > > pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); > > If a dt contains > > mediatek,num-pwms = <17>; > > you're accessing pc->clks[18] which is an out-of-bounds access, so > better check the limit or allocate the clks array dynamically. > Thanks for the reminder. I will fix it in v2. Ryder
Hello Ryder, On Fri, Jan 18, 2019 at 05:42:54PM +0800, Ryder Lee wrote: > On Fri, 2019-01-18 at 08:59 +0100, Uwe Kleine-König wrote: > > Hello, > > > > On Fri, Jan 18, 2019 at 11:24:41AM +0800, Ryder Lee wrote: > > > This adds a property "mediatek,num-pwms" to avoid having an endless > > > list of compatibles with no differences for the same driver. > > > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > I still think Thierry should bless "num-pwms" without vendor prefix. > > Okay. > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > > --- > > > Changes since v1: add some checks for backwards compatibility. > > > --- > > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > > index eb6674c..81b7e5e 100644 > > > --- a/drivers/pwm/pwm-mediatek.c > > > +++ b/drivers/pwm/pwm-mediatek.c > > > @@ -55,7 +55,7 @@ enum { > > > }; > > > > > > struct mtk_pwm_platform_data { > > > > Unrelated to this patch: This name is bad. This struct is not used as > > platform_data and so should better be named mtk_pwm_of_data. While at > > criticizing existing stuff: I'd prefer pwm_mediatek as common prefix to > > match the filename. > > I think we can take care about that in another patch. That's what I wanted to say, right. Do you follow up? > > > - unsigned int num_pwms; > > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > > > I'd drop this comment in favour of a runtime warning. > > Sorry, I can't get you here. I'd do a dev_warn(dev, "dt didn't specify number of PWMs, falling back to %d\n", pc->soc->num_pwms); to make people aware that updating the dt would be nice. > > > > bool pwm45_fixup; > > > bool has_clks; > > > }; > > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > > { > > > - const struct mtk_pwm_platform_data *data; > > > + struct device_node *np = pdev->dev.of_node; > > > struct mtk_pwm_chip *pc; > > > struct resource *res; > > > - unsigned int i; > > > + unsigned int i, num_pwms; > > > int ret; > > > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > > if (!pc) > > > return -ENOMEM; > > > > > > - data = of_device_get_match_data(&pdev->dev); > > > - if (data == NULL) > > > - return -EINVAL; > > > - pc->soc = data; > > > + pc->soc = of_device_get_match_data(&pdev->dev); > > > > This might return NULL which ... > > The only way to call probe() is to match an entry in > mtk_pwm_of_match[], so match cannot be NULL. (<pedantic>Theoretically the driver can be probed by device name, but that is not what I meant here.</pedantic>). You're right, as long as all entries in mtk_pwm_of_match have a non-NULL .data entry, you're fine. I somehow thought there might be some without one. I wouldn't oppose to check for that anyhow as a defensive measure. > > > [...] > > > + /* Check if we have set 'num-pwms' in DTs. */ > > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > > + if (ret < 0) { > > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > > + if (pc->soc->num_pwms) { > > > > ... here then results in a NULL pointer dereference. I think you want > > So we have no chance to get a NULL pointer, right? Ack. Best regards Uwe
On Fri, 2019-01-18 at 10:53 +0100, Uwe Kleine-König wrote: > Hello Ryder, > > On Fri, Jan 18, 2019 at 05:42:54PM +0800, Ryder Lee wrote: > > On Fri, 2019-01-18 at 08:59 +0100, Uwe Kleine-König wrote: > > > Hello, > > > > > > On Fri, Jan 18, 2019 at 11:24:41AM +0800, Ryder Lee wrote: > > > > This adds a property "mediatek,num-pwms" to avoid having an endless > > > > list of compatibles with no differences for the same driver. > > > > > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > > > I still think Thierry should bless "num-pwms" without vendor prefix. > > > > Okay. > > > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > > > --- > > > > Changes since v1: add some checks for backwards compatibility. > > > > --- > > > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > > > index eb6674c..81b7e5e 100644 > > > > --- a/drivers/pwm/pwm-mediatek.c > > > > +++ b/drivers/pwm/pwm-mediatek.c > > > > @@ -55,7 +55,7 @@ enum { > > > > }; > > > > > > > > struct mtk_pwm_platform_data { > > > > > > Unrelated to this patch: This name is bad. This struct is not used as > > > platform_data and so should better be named mtk_pwm_of_data. While at > > > criticizing existing stuff: I'd prefer pwm_mediatek as common prefix to > > > match the filename. > > > > I think we can take care about that in another patch. > > That's what I wanted to say, right. Do you follow up? Yes, I will do that. > > > > - unsigned int num_pwms; > > > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > > > > > I'd drop this comment in favour of a runtime warning. > > > > Sorry, I can't get you here. > > I'd do a > > dev_warn(dev, "dt didn't specify number of PWMs, falling back to %d\n", pc->soc->num_pwms); > > to make people aware that updating the dt would be nice. Okay! Thanks Ryder
On Fri, 2019-01-18 at 09:43 +0100, Matthias Brugger wrote: > > On 18/01/2019 04:24, Ryder Lee wrote: > > This adds a property "mediatek,num-pwms" to avoid having an endless > > list of compatibles with no differences for the same driver. > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > --- > > Changes since v1: add some checks for backwards compatibility. > > --- > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > index eb6674c..81b7e5e 100644 > > --- a/drivers/pwm/pwm-mediatek.c > > +++ b/drivers/pwm/pwm-mediatek.c > > @@ -55,7 +55,7 @@ enum { > > }; > > > > struct mtk_pwm_platform_data { > > - unsigned int num_pwms; > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > bool pwm45_fixup; > > bool has_clks; > > }; > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > { > > - const struct mtk_pwm_platform_data *data; > > + struct device_node *np = pdev->dev.of_node; > > struct mtk_pwm_chip *pc; > > struct resource *res; > > - unsigned int i; > > + unsigned int i, num_pwms; > > int ret; > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > if (!pc) > > return -ENOMEM; > > > > - data = of_device_get_match_data(&pdev->dev); > > - if (data == NULL) > > - return -EINVAL; > > - pc->soc = data; > > + pc->soc = of_device_get_match_data(&pdev->dev); > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > pc->regs = devm_ioremap_resource(&pdev->dev, res); > > if (IS_ERR(pc->regs)) > > return PTR_ERR(pc->regs); > > > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > > + /* Check if we have set 'num-pwms' in DTs. */ > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > + if (ret < 0) { > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > + if (pc->soc->num_pwms) { > > + num_pwms = pc->soc->num_pwms; > > Maybe that's bike shedding, but I think it would be better to carve out the > num_pwms from the mtk_pwm_platform_data and check against the compatible here. I'm not sure how to properly curve it out? I think we still need this variable to save the specific value for some legacy SoCs (with older DTs). > With a expressive comment it will help other driver developers to not start > adding num_pwms in the platform data in their first attempt. Definitely. Ryder > > > + } else { > > + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); > > + return ret; > > + } > > + } > > + > > + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { > > pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); > > if (IS_ERR(pc->clks[i])) { > > dev_err(&pdev->dev, "clock: %s fail: %ld\n", > > @@ -260,7 +269,7 @@ static int mtk_pwm_probe(struct platform_device *pdev) > > pc->chip.dev = &pdev->dev; > > pc->chip.ops = &mtk_pwm_ops; > > pc->chip.base = -1; > > - pc->chip.npwm = data->num_pwms; > > + pc->chip.npwm = num_pwms; > > > > ret = pwmchip_add(&pc->chip); > > if (ret < 0) { > >
On Sat, Jan 19, 2019 at 10:54:47AM +0800, Ryder Lee wrote: > On Fri, 2019-01-18 at 09:43 +0100, Matthias Brugger wrote: > > > > On 18/01/2019 04:24, Ryder Lee wrote: > > > This adds a property "mediatek,num-pwms" to avoid having an endless > > > list of compatibles with no differences for the same driver. > > > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > > --- > > > Changes since v1: add some checks for backwards compatibility. > > > --- > > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > > index eb6674c..81b7e5e 100644 > > > --- a/drivers/pwm/pwm-mediatek.c > > > +++ b/drivers/pwm/pwm-mediatek.c > > > @@ -55,7 +55,7 @@ enum { > > > }; > > > > > > struct mtk_pwm_platform_data { > > > - unsigned int num_pwms; > > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > > bool pwm45_fixup; > > > bool has_clks; > > > }; > > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > > { > > > - const struct mtk_pwm_platform_data *data; > > > + struct device_node *np = pdev->dev.of_node; > > > struct mtk_pwm_chip *pc; > > > struct resource *res; > > > - unsigned int i; > > > + unsigned int i, num_pwms; > > > int ret; > > > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > > if (!pc) > > > return -ENOMEM; > > > > > > - data = of_device_get_match_data(&pdev->dev); > > > - if (data == NULL) > > > - return -EINVAL; > > > - pc->soc = data; > > > + pc->soc = of_device_get_match_data(&pdev->dev); > > > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > pc->regs = devm_ioremap_resource(&pdev->dev, res); > > > if (IS_ERR(pc->regs)) > > > return PTR_ERR(pc->regs); > > > > > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > > > + /* Check if we have set 'num-pwms' in DTs. */ > > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > > + if (ret < 0) { > > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > > + if (pc->soc->num_pwms) { > > > + num_pwms = pc->soc->num_pwms; > > > > Maybe that's bike shedding, but I think it would be better to carve out the > > num_pwms from the mtk_pwm_platform_data and check against the compatible here. > > I'm not sure how to properly curve it out? I think we still need this > variable to save the specific value for some legacy SoCs (with older > DTs). I guess he means something like: if (is_compatible_to_variant_A(dev)) num_pwms = 12; else if (is_compatible_to_variant_B(dev)) num_pwms = 2; . In my eyes the bike shed should be light red and I prefer to collect the fallback num_pwms in the compatible_data as is to keep the code simpler. Maybe rename the member from num_pwms to fallback_num_pwms to make it more obvious that it doesn't represent the actually used value. > > With a expressive comment it will help other driver developers to not start > > adding num_pwms in the platform data in their first attempt. > > Definitely. My suggestion was to add a dev_warn, which IMHO is still better than a comment. Best regards Uwe
+John HI John, On Mon, 2019-01-21 at 16:49 +0800, Uwe Kleine-König wrote: > On Sat, Jan 19, 2019 at 10:54:47AM +0800, Ryder Lee wrote: > > On Fri, 2019-01-18 at 09:43 +0100, Matthias Brugger wrote: > > > > > > On 18/01/2019 04:24, Ryder Lee wrote: > > > > This adds a property "mediatek,num-pwms" to avoid having an endless > > > > list of compatibles with no differences for the same driver. > > > > > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > > > --- > > > > Changes since v1: add some checks for backwards compatibility. > > > > --- > > > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > > > index eb6674c..81b7e5e 100644 > > > > --- a/drivers/pwm/pwm-mediatek.c > > > > +++ b/drivers/pwm/pwm-mediatek.c > > > > @@ -55,7 +55,7 @@ enum { > > > > }; > > > > > > > > struct mtk_pwm_platform_data { > > > > - unsigned int num_pwms; > > > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > > > bool pwm45_fixup; > > > > bool has_clks; > > > > }; > > > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > > > { > > > > - const struct mtk_pwm_platform_data *data; > > > > + struct device_node *np = pdev->dev.of_node; > > > > struct mtk_pwm_chip *pc; > > > > struct resource *res; > > > > - unsigned int i; > > > > + unsigned int i, num_pwms; > > > > int ret; > > > > > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > > > if (!pc) > > > > return -ENOMEM; > > > > > > > > - data = of_device_get_match_data(&pdev->dev); > > > > - if (data == NULL) > > > > - return -EINVAL; > > > > - pc->soc = data; > > > > + pc->soc = of_device_get_match_data(&pdev->dev); > > > > > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > > pc->regs = devm_ioremap_resource(&pdev->dev, res); > > > > if (IS_ERR(pc->regs)) > > > > return PTR_ERR(pc->regs); > > > > > > > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > > > > + /* Check if we have set 'num-pwms' in DTs. */ > > > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > > > + if (ret < 0) { > > > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > > > + if (pc->soc->num_pwms) { > > > > + num_pwms = pc->soc->num_pwms; > > > > > > Maybe that's bike shedding, but I think it would be better to carve out the > > > num_pwms from the mtk_pwm_platform_data and check against the compatible here. > > > > I'm not sure how to properly curve it out? I think we still need this > > variable to save the specific value for some legacy SoCs (with older > > DTs). > > I guess he means something like: > > if (is_compatible_to_variant_A(dev)) > num_pwms = 12; > else if (is_compatible_to_variant_B(dev)) > num_pwms = 2; > > . In my eyes the bike shed should be light red and I prefer to collect > the fallback num_pwms in the compatible_data as is to keep the code > simpler. Maybe rename the member from num_pwms to fallback_num_pwms to > make it more obvious that it doesn't represent the actually used value. > > > > With a expressive comment it will help other driver developers to not start > > > adding num_pwms in the platform data in their first attempt. > > > > Definitely. > > My suggestion was to add a dev_warn, which IMHO is still better than a > comment. > > Best regards > Uwe > Unrelated to this patch: I'm ready to send v2 to allocate the clks array dynamically, but I guess MT7628 couldn't work in original code. In mtk_pwm_config(): clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]; .... resolution = (u64)NSEC_PER_SEC * 1000; do_div(resolution, clk_get_rate(clk)); .... I think clk should be NULL and resolution is always 0 here. Ryder
+John HI John, On Mon, 2019-01-21 at 16:49 +0800, Uwe Kleine-König wrote: > On Sat, Jan 19, 2019 at 10:54:47AM +0800, Ryder Lee wrote: > > On Fri, 2019-01-18 at 09:43 +0100, Matthias Brugger wrote: > > > > > > On 18/01/2019 04:24, Ryder Lee wrote: > > > > This adds a property "mediatek,num-pwms" to avoid having an endless > > > > list of compatibles with no differences for the same driver. > > > > > > > > Thus, the driver should have backwards compatibility to older DTs. > > > > > > > > Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> > > > > --- > > > > Changes since v1: add some checks for backwards compatibility. > > > > --- > > > > drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- > > > > 1 file changed, 18 insertions(+), 9 deletions(-) > > > > > > > > diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c > > > > index eb6674c..81b7e5e 100644 > > > > --- a/drivers/pwm/pwm-mediatek.c > > > > +++ b/drivers/pwm/pwm-mediatek.c > > > > @@ -55,7 +55,7 @@ enum { > > > > }; > > > > > > > > struct mtk_pwm_platform_data { > > > > - unsigned int num_pwms; > > > > + unsigned int num_pwms; /* it should not be used in the future SoCs */ > > > > bool pwm45_fixup; > > > > bool has_clks; > > > > }; > > > > @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > > > > > > > > static int mtk_pwm_probe(struct platform_device *pdev) > > > > { > > > > - const struct mtk_pwm_platform_data *data; > > > > + struct device_node *np = pdev->dev.of_node; > > > > struct mtk_pwm_chip *pc; > > > > struct resource *res; > > > > - unsigned int i; > > > > + unsigned int i, num_pwms; > > > > int ret; > > > > > > > > pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); > > > > if (!pc) > > > > return -ENOMEM; > > > > > > > > - data = of_device_get_match_data(&pdev->dev); > > > > - if (data == NULL) > > > > - return -EINVAL; > > > > - pc->soc = data; > > > > + pc->soc = of_device_get_match_data(&pdev->dev); > > > > > > > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > > > pc->regs = devm_ioremap_resource(&pdev->dev, res); > > > > if (IS_ERR(pc->regs)) > > > > return PTR_ERR(pc->regs); > > > > > > > > - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { > > > > + /* Check if we have set 'num-pwms' in DTs. */ > > > > + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); > > > > + if (ret < 0) { > > > > + /* If no, fallback to use SoC data for backwards compatibility. */ > > > > + if (pc->soc->num_pwms) { > > > > + num_pwms = pc->soc->num_pwms; > > > > > > Maybe that's bike shedding, but I think it would be better to carve out the > > > num_pwms from the mtk_pwm_platform_data and check against the compatible here. > > > > I'm not sure how to properly curve it out? I think we still need this > > variable to save the specific value for some legacy SoCs (with older > > DTs). > > I guess he means something like: > > if (is_compatible_to_variant_A(dev)) > num_pwms = 12; > else if (is_compatible_to_variant_B(dev)) > num_pwms = 2; > > . In my eyes the bike shed should be light red and I prefer to collect > the fallback num_pwms in the compatible_data as is to keep the code > simpler. Maybe rename the member from num_pwms to fallback_num_pwms to > make it more obvious that it doesn't represent the actually used value. > > > > With a expressive comment it will help other driver developers to not start > > > adding num_pwms in the platform data in their first attempt. > > > > Definitely. > > My suggestion was to add a dev_warn, which IMHO is still better than a > comment. > > Best regards > Uwe > Unrelated to this patch: I'm ready to send v2 to allocate the clks array dynamically, but I guess MT7628 couldn't work in original code. In mtk_pwm_config(): clk = pc->clks[MTK_CLK_PWM1 + pwm->hwpwm]; .... resolution = (u64)NSEC_PER_SEC * 1000; do_div(resolution, clk_get_rate(clk)); .... I think clk should be NULL and resolution is always 0 here. Ryder
diff --git a/drivers/pwm/pwm-mediatek.c b/drivers/pwm/pwm-mediatek.c index eb6674c..81b7e5e 100644 --- a/drivers/pwm/pwm-mediatek.c +++ b/drivers/pwm/pwm-mediatek.c @@ -55,7 +55,7 @@ enum { }; struct mtk_pwm_platform_data { - unsigned int num_pwms; + unsigned int num_pwms; /* it should not be used in the future SoCs */ bool pwm45_fixup; bool has_clks; }; @@ -226,27 +226,36 @@ static void mtk_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) static int mtk_pwm_probe(struct platform_device *pdev) { - const struct mtk_pwm_platform_data *data; + struct device_node *np = pdev->dev.of_node; struct mtk_pwm_chip *pc; struct resource *res; - unsigned int i; + unsigned int i, num_pwms; int ret; pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); if (!pc) return -ENOMEM; - data = of_device_get_match_data(&pdev->dev); - if (data == NULL) - return -EINVAL; - pc->soc = data; + pc->soc = of_device_get_match_data(&pdev->dev); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); pc->regs = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(pc->regs)) return PTR_ERR(pc->regs); - for (i = 0; i < data->num_pwms + 2 && pc->soc->has_clks; i++) { + /* Check if we have set 'num-pwms' in DTs. */ + ret = of_property_read_u32(np, "mediatek,num-pwms", &num_pwms); + if (ret < 0) { + /* If no, fallback to use SoC data for backwards compatibility. */ + if (pc->soc->num_pwms) { + num_pwms = pc->soc->num_pwms; + } else { + dev_err(&pdev->dev, "failed to get pwm number: %d\n", ret); + return ret; + } + } + + for (i = 0; i < num_pwms + 2 && pc->soc->has_clks; i++) { pc->clks[i] = devm_clk_get(&pdev->dev, mtk_pwm_clk_name[i]); if (IS_ERR(pc->clks[i])) { dev_err(&pdev->dev, "clock: %s fail: %ld\n", @@ -260,7 +269,7 @@ static int mtk_pwm_probe(struct platform_device *pdev) pc->chip.dev = &pdev->dev; pc->chip.ops = &mtk_pwm_ops; pc->chip.base = -1; - pc->chip.npwm = data->num_pwms; + pc->chip.npwm = num_pwms; ret = pwmchip_add(&pc->chip); if (ret < 0) {
This adds a property "mediatek,num-pwms" to avoid having an endless list of compatibles with no differences for the same driver. Thus, the driver should have backwards compatibility to older DTs. Signed-off-by: Ryder Lee <ryder.lee@mediatek.com> --- Changes since v1: add some checks for backwards compatibility. --- drivers/pwm/pwm-mediatek.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-)