| Message ID | 1483573014-13185-3-git-send-email-lukma@denx.de |
|---|---|
| State | Superseded |
| Headers | show |
On Thu, 5 Jan 2017 00:36:45 +0100 Lukasz Majewski <lukma@denx.de> wrote: > From: Boris Brezillon <boris.brezillon@free-electrons.com> Can you keep Sascha as the author of this patch? > > The use of the ipg clock was introduced with commit 7b27c160c681 > ("pwm: i.MX: fix clock lookup"). > In the commit message it was claimed that the ipg clock is enabled for > register accesses. This is true for the ->config() callback, but not > for the ->set_enable() callback. Given that the ipg clock is not > consistently enabled for all register accesses we can assume that either > it is not required at all or that the current code does not work. > Remove the ipg clock code for now so that it's no longer in the way of > refactoring the driver. > > In the other hand, the imx7 IP requires the peripheral clock to be > enabled before accessing its registers. Since ->config() can be called > when the PWM is disabled (in which case, the peripheral clock is also > disabled), we need to surround the imx->config() with > clk_prepare_enable(per_clk)/clk_disable_unprepare(per_clk) calls. > > Note that the imx7 IP was working fine so far because the ipg clock was > actually pointing to the peripheral clock, which guaranteed peripheral > clock activation even when ->config() was called when the PWM was > disabled. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > Cc: Philipp Zabel <p.zabel@pengutronix.de> > --- > Changes in v4: > - Enable per clk before calling imx->config() > > Changes in v3: > - New patch > --- > drivers/pwm/pwm-imx.c | 12 ++---------- > 1 file changed, 2 insertions(+), 10 deletions(-) > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > index d600fd5..b1d1e50 100644 > --- a/drivers/pwm/pwm-imx.c > +++ b/drivers/pwm/pwm-imx.c > @@ -49,7 +49,6 @@ > > struct imx_chip { > struct clk *clk_per; > - struct clk *clk_ipg; > > void __iomem *mmio_base; > > @@ -206,13 +205,13 @@ static int imx_pwm_config(struct pwm_chip *chip, > struct imx_chip *imx = to_imx_chip(chip); > int ret; > > - ret = clk_prepare_enable(imx->clk_ipg); > + ret = clk_prepare_enable(imx->clk_per); > if (ret) > return ret; > > ret = imx->config(chip, pwm, duty_ns, period_ns); > > - clk_disable_unprepare(imx->clk_ipg); > + clk_disable_unprepare(imx->clk_per); > > return ret; > } > @@ -293,13 +292,6 @@ static int imx_pwm_probe(struct platform_device *pdev) > return PTR_ERR(imx->clk_per); > } > > - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); > - if (IS_ERR(imx->clk_ipg)) { > - dev_err(&pdev->dev, "getting ipg clock failed with %ld\n", > - PTR_ERR(imx->clk_ipg)); > - return PTR_ERR(imx->clk_ipg); > - } > - > imx->chip.ops = &imx_pwm_ops; > imx->chip.dev = &pdev->dev; > imx->chip.base = -1; -- 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
Hi Boris, > On Thu, 5 Jan 2017 00:36:45 +0100 > Lukasz Majewski <lukma@denx.de> wrote: > > > From: Boris Brezillon <boris.brezillon@free-electrons.com> > > Can you keep Sascha as the author of this patch? But the patch differs from the original one - and that change was sent by you - so I assume that you made the modifications. Apparently there are two authors and we only have one "Author" field :-) so I took the patch as it was sent by you. Is the rest of the series correct? Best regards, Łukasz Majewski > > > > > The use of the ipg clock was introduced with commit 7b27c160c681 > > ("pwm: i.MX: fix clock lookup"). > > In the commit message it was claimed that the ipg clock is enabled > > for register accesses. This is true for the ->config() callback, > > but not for the ->set_enable() callback. Given that the ipg clock > > is not consistently enabled for all register accesses we can assume > > that either it is not required at all or that the current code does > > not work. Remove the ipg clock code for now so that it's no longer > > in the way of refactoring the driver. > > > > In the other hand, the imx7 IP requires the peripheral clock to be > > enabled before accessing its registers. Since ->config() can be > > called when the PWM is disabled (in which case, the peripheral > > clock is also disabled), we need to surround the imx->config() with > > clk_prepare_enable(per_clk)/clk_disable_unprepare(per_clk) calls. > > > > Note that the imx7 IP was working fine so far because the ipg clock > > was actually pointing to the peripheral clock, which guaranteed > > peripheral clock activation even when ->config() was called when > > the PWM was disabled. > > > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > Cc: Philipp Zabel <p.zabel@pengutronix.de> > > --- > > Changes in v4: > > - Enable per clk before calling imx->config() > > > > Changes in v3: > > - New patch > > --- > > drivers/pwm/pwm-imx.c | 12 ++---------- > > 1 file changed, 2 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > > index d600fd5..b1d1e50 100644 > > --- a/drivers/pwm/pwm-imx.c > > +++ b/drivers/pwm/pwm-imx.c > > @@ -49,7 +49,6 @@ > > > > struct imx_chip { > > struct clk *clk_per; > > - struct clk *clk_ipg; > > > > void __iomem *mmio_base; > > > > @@ -206,13 +205,13 @@ static int imx_pwm_config(struct pwm_chip > > *chip, struct imx_chip *imx = to_imx_chip(chip); > > int ret; > > > > - ret = clk_prepare_enable(imx->clk_ipg); > > + ret = clk_prepare_enable(imx->clk_per); > > if (ret) > > return ret; > > > > ret = imx->config(chip, pwm, duty_ns, period_ns); > > > > - clk_disable_unprepare(imx->clk_ipg); > > + clk_disable_unprepare(imx->clk_per); > > > > return ret; > > } > > @@ -293,13 +292,6 @@ static int imx_pwm_probe(struct > > platform_device *pdev) return PTR_ERR(imx->clk_per); > > } > > > > - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); > > - if (IS_ERR(imx->clk_ipg)) { > > - dev_err(&pdev->dev, "getting ipg clock failed with > > %ld\n", > > - PTR_ERR(imx->clk_ipg)); > > - return PTR_ERR(imx->clk_ipg); > > - } > > - > > imx->chip.ops = &imx_pwm_ops; > > imx->chip.dev = &pdev->dev; > > imx->chip.base = -1; > Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de -- 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 Thu, 5 Jan 2017 08:26:09 +0100 Lukasz Majewski <lukma@denx.de> wrote: > Hi Boris, > > > On Thu, 5 Jan 2017 00:36:45 +0100 > > Lukasz Majewski <lukma@denx.de> wrote: > > > > > From: Boris Brezillon <boris.brezillon@free-electrons.com> > > > > Can you keep Sascha as the author of this patch? > > But the patch differs from the original one - and that change was sent > by you - so I assume that you made the modifications. > > Apparently there are two authors and we only have one "Author" > field :-) so I took the patch as it was sent by you. Well, when the changes are substantial it can be justified, but here the changes are trivial (2 lines changed), and I don't think it calls for an authorship change (unless Sascha doesn't want to take the responsibility for those 2 lines). > > Is the rest of the series correct? I'll have a look. > > Best regards, > Łukasz Majewski > > > > > > > > > The use of the ipg clock was introduced with commit 7b27c160c681 > > > ("pwm: i.MX: fix clock lookup"). > > > In the commit message it was claimed that the ipg clock is enabled > > > for register accesses. This is true for the ->config() callback, > > > but not for the ->set_enable() callback. Given that the ipg clock > > > is not consistently enabled for all register accesses we can assume > > > that either it is not required at all or that the current code does > > > not work. Remove the ipg clock code for now so that it's no longer > > > in the way of refactoring the driver. > > > > > > In the other hand, the imx7 IP requires the peripheral clock to be > > > enabled before accessing its registers. Since ->config() can be > > > called when the PWM is disabled (in which case, the peripheral > > > clock is also disabled), we need to surround the imx->config() with > > > clk_prepare_enable(per_clk)/clk_disable_unprepare(per_clk) calls. > > > > > > Note that the imx7 IP was working fine so far because the ipg clock > > > was actually pointing to the peripheral clock, which guaranteed > > > peripheral clock activation even when ->config() was called when > > > the PWM was disabled. > > > > > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > > > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > > > Cc: Philipp Zabel <p.zabel@pengutronix.de> > > > --- > > > Changes in v4: > > > - Enable per clk before calling imx->config() > > > > > > Changes in v3: > > > - New patch > > > --- > > > drivers/pwm/pwm-imx.c | 12 ++---------- > > > 1 file changed, 2 insertions(+), 10 deletions(-) > > > > > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > > > index d600fd5..b1d1e50 100644 > > > --- a/drivers/pwm/pwm-imx.c > > > +++ b/drivers/pwm/pwm-imx.c > > > @@ -49,7 +49,6 @@ > > > > > > struct imx_chip { > > > struct clk *clk_per; > > > - struct clk *clk_ipg; > > > > > > void __iomem *mmio_base; > > > > > > @@ -206,13 +205,13 @@ static int imx_pwm_config(struct pwm_chip > > > *chip, struct imx_chip *imx = to_imx_chip(chip); > > > int ret; > > > > > > - ret = clk_prepare_enable(imx->clk_ipg); > > > + ret = clk_prepare_enable(imx->clk_per); > > > if (ret) > > > return ret; > > > > > > ret = imx->config(chip, pwm, duty_ns, period_ns); > > > > > > - clk_disable_unprepare(imx->clk_ipg); > > > + clk_disable_unprepare(imx->clk_per); > > > > > > return ret; > > > } > > > @@ -293,13 +292,6 @@ static int imx_pwm_probe(struct > > > platform_device *pdev) return PTR_ERR(imx->clk_per); > > > } > > > > > > - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); > > > - if (IS_ERR(imx->clk_ipg)) { > > > - dev_err(&pdev->dev, "getting ipg clock failed with > > > %ld\n", > > > - PTR_ERR(imx->clk_ipg)); > > > - return PTR_ERR(imx->clk_ipg); > > > - } > > > - > > > imx->chip.ops = &imx_pwm_ops; > > > imx->chip.dev = &pdev->dev; > > > imx->chip.base = -1; > > > > > > > Best regards, > > Lukasz Majewski > > -- > > DENX Software Engineering GmbH, Managing Director: Wolfgang Denk > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de -- 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
Hi Boris, > On Thu, 5 Jan 2017 08:26:09 +0100 > Lukasz Majewski <lukma@denx.de> wrote: > > > Hi Boris, > > > > > On Thu, 5 Jan 2017 00:36:45 +0100 > > > Lukasz Majewski <lukma@denx.de> wrote: > > > > > > > From: Boris Brezillon <boris.brezillon@free-electrons.com> > > > > > > Can you keep Sascha as the author of this patch? > > > > But the patch differs from the original one - and that change was > > sent by you - so I assume that you made the modifications. > > > > Apparently there are two authors and we only have one "Author" > > field :-) so I took the patch as it was sent by you. > > Well, when the changes are substantial it can be justified, but here > the changes are trivial (2 lines changed), and I don't think it calls > for an authorship change (unless Sascha doesn't want to take the > responsibility for those 2 lines). > I will correct this if v5 is required, otherwise I can re-send only this single patch. > > > > Is the rest of the series correct? > > I'll have a look. Ok. > > > > > Best regards, > > Łukasz Majewski > > > > > > > > > > > > > The use of the ipg clock was introduced with commit 7b27c160c681 > > > > ("pwm: i.MX: fix clock lookup"). > > > > In the commit message it was claimed that the ipg clock is > > > > enabled for register accesses. This is true for the ->config() > > > > callback, but not for the ->set_enable() callback. Given that > > > > the ipg clock is not consistently enabled for all register > > > > accesses we can assume that either it is not required at all or > > > > that the current code does not work. Remove the ipg clock code > > > > for now so that it's no longer in the way of refactoring the > > > > driver. > > > > > > > > In the other hand, the imx7 IP requires the peripheral clock to > > > > be enabled before accessing its registers. Since ->config() can > > > > be called when the PWM is disabled (in which case, the > > > > peripheral clock is also disabled), we need to surround the > > > > imx->config() with > > > > clk_prepare_enable(per_clk)/clk_disable_unprepare(per_clk) > > > > calls. > > > > > > > > Note that the imx7 IP was working fine so far because the ipg > > > > clock was actually pointing to the peripheral clock, which > > > > guaranteed peripheral clock activation even when ->config() was > > > > called when the PWM was disabled. > > > > > > > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > > > > Signed-off-by: Boris Brezillon > > > > <boris.brezillon@free-electrons.com> Cc: Philipp Zabel > > > > <p.zabel@pengutronix.de> --- > > > > Changes in v4: > > > > - Enable per clk before calling imx->config() > > > > > > > > Changes in v3: > > > > - New patch > > > > --- > > > > drivers/pwm/pwm-imx.c | 12 ++---------- > > > > 1 file changed, 2 insertions(+), 10 deletions(-) > > > > > > > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > > > > index d600fd5..b1d1e50 100644 > > > > --- a/drivers/pwm/pwm-imx.c > > > > +++ b/drivers/pwm/pwm-imx.c > > > > @@ -49,7 +49,6 @@ > > > > > > > > struct imx_chip { > > > > struct clk *clk_per; > > > > - struct clk *clk_ipg; > > > > > > > > void __iomem *mmio_base; > > > > > > > > @@ -206,13 +205,13 @@ static int imx_pwm_config(struct pwm_chip > > > > *chip, struct imx_chip *imx = to_imx_chip(chip); > > > > int ret; > > > > > > > > - ret = clk_prepare_enable(imx->clk_ipg); > > > > + ret = clk_prepare_enable(imx->clk_per); > > > > if (ret) > > > > return ret; > > > > > > > > ret = imx->config(chip, pwm, duty_ns, period_ns); > > > > > > > > - clk_disable_unprepare(imx->clk_ipg); > > > > + clk_disable_unprepare(imx->clk_per); > > > > > > > > return ret; > > > > } > > > > @@ -293,13 +292,6 @@ static int imx_pwm_probe(struct > > > > platform_device *pdev) return PTR_ERR(imx->clk_per); > > > > } > > > > > > > > - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); > > > > - if (IS_ERR(imx->clk_ipg)) { > > > > - dev_err(&pdev->dev, "getting ipg clock failed > > > > with %ld\n", > > > > - PTR_ERR(imx->clk_ipg)); > > > > - return PTR_ERR(imx->clk_ipg); > > > > - } > > > > - > > > > imx->chip.ops = &imx_pwm_ops; > > > > imx->chip.dev = &pdev->dev; > > > > imx->chip.base = -1; > > > > > > > > > > > > > Best regards, > > > > Lukasz Majewski > > > > -- > > > > DENX Software Engineering GmbH, Managing Director: Wolfgang > > Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, > > Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: > > wd@denx.de > Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de -- 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 2017-01-04 15:36, Lukasz Majewski wrote: > From: Boris Brezillon <boris.brezillon@free-electrons.com> > > The use of the ipg clock was introduced with commit 7b27c160c681 > ("pwm: i.MX: fix clock lookup"). > In the commit message it was claimed that the ipg clock is enabled for > register accesses. This is true for the ->config() callback, but not > for the ->set_enable() callback. Given that the ipg clock is not > consistently enabled for all register accesses we can assume that either > it is not required at all or that the current code does not work. > Remove the ipg clock code for now so that it's no longer in the way of > refactoring the driver. > > In the other hand, the imx7 IP requires the peripheral clock to be Nit: s/In/On? > enabled before accessing its registers. Since ->config() can be called > when the PWM is disabled (in which case, the peripheral clock is also > disabled), we need to surround the imx->config() with > clk_prepare_enable(per_clk)/clk_disable_unprepare(per_clk) calls. > > Note that the imx7 IP was working fine so far because the ipg clock was > actually pointing to the peripheral clock, which guaranteed peripheral > clock activation even when ->config() was called when the PWM was > disabled. That is not entirely true, but almost, I would say: "Note that the driver was working fine for the i.MX 7 IP so far because the ipg and peripheral clock use the same hardware clock gate, which guaranteed..." > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> > Cc: Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by: Stefan Agner <stefan@agner.ch> Tried on-top of 4.10-rc3, only this patch, still works. Tested-by: Stefan Agner <stefan@agner.ch> -- Stefan > --- > Changes in v4: > - Enable per clk before calling imx->config() > > Changes in v3: > - New patch > --- > drivers/pwm/pwm-imx.c | 12 ++---------- > 1 file changed, 2 insertions(+), 10 deletions(-) > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > index d600fd5..b1d1e50 100644 > --- a/drivers/pwm/pwm-imx.c > +++ b/drivers/pwm/pwm-imx.c > @@ -49,7 +49,6 @@ > > struct imx_chip { > struct clk *clk_per; > - struct clk *clk_ipg; > > void __iomem *mmio_base; > > @@ -206,13 +205,13 @@ static int imx_pwm_config(struct pwm_chip *chip, > struct imx_chip *imx = to_imx_chip(chip); > int ret; > > - ret = clk_prepare_enable(imx->clk_ipg); > + ret = clk_prepare_enable(imx->clk_per); > if (ret) > return ret; > > ret = imx->config(chip, pwm, duty_ns, period_ns); > > - clk_disable_unprepare(imx->clk_ipg); > + clk_disable_unprepare(imx->clk_per); > > return ret; > } > @@ -293,13 +292,6 @@ static int imx_pwm_probe(struct platform_device *pdev) > return PTR_ERR(imx->clk_per); > } > > - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); > - if (IS_ERR(imx->clk_ipg)) { > - dev_err(&pdev->dev, "getting ipg clock failed with %ld\n", > - PTR_ERR(imx->clk_ipg)); > - return PTR_ERR(imx->clk_ipg); > - } > - > imx->chip.ops = &imx_pwm_ops; > imx->chip.dev = &pdev->dev; > imx->chip.base = -1; -- 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
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c index d600fd5..b1d1e50 100644 --- a/drivers/pwm/pwm-imx.c +++ b/drivers/pwm/pwm-imx.c @@ -49,7 +49,6 @@ struct imx_chip { struct clk *clk_per; - struct clk *clk_ipg; void __iomem *mmio_base; @@ -206,13 +205,13 @@ static int imx_pwm_config(struct pwm_chip *chip, struct imx_chip *imx = to_imx_chip(chip); int ret; - ret = clk_prepare_enable(imx->clk_ipg); + ret = clk_prepare_enable(imx->clk_per); if (ret) return ret; ret = imx->config(chip, pwm, duty_ns, period_ns); - clk_disable_unprepare(imx->clk_ipg); + clk_disable_unprepare(imx->clk_per); return ret; } @@ -293,13 +292,6 @@ static int imx_pwm_probe(struct platform_device *pdev) return PTR_ERR(imx->clk_per); } - imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); - if (IS_ERR(imx->clk_ipg)) { - dev_err(&pdev->dev, "getting ipg clock failed with %ld\n", - PTR_ERR(imx->clk_ipg)); - return PTR_ERR(imx->clk_ipg); - } - imx->chip.ops = &imx_pwm_ops; imx->chip.dev = &pdev->dev; imx->chip.base = -1;