| Message ID | 1399883945-22500-1-git-send-email-arun.kk@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, Any comments on this patch? If this approach is ok, then I can drop the RFC tag and resend this for merging? Regards Arun On Mon, May 12, 2014 at 2:09 PM, Arun Kumar K <arun.kk@samsung.com> wrote: > From: Prathyush K <prathyush.k@samsung.com> > > While powering on/off a local powerdomain in exynos5 chipsets, the input > clocks to each device gets modified. This behaviour is based on the > SYSCLK_SYS_PWR_REG registers. > E.g. SYSCLK_MFC_SYS_PWR_REG = 0x0, the parent of input clock to MFC > (aclk333) gets modified to oscclk > = 0x1, no change in clocks. > The recommended value of SYSCLK_SYS_PWR_REG before power gating any > domain is 0x0. So we must also restore the clocks while powering on a > domain everytime. > > This patch adds the framework for getting the required mux and parent clocks > through a power domain device node. > Just setting the parent while powering on is not enough since according > to the clock framework, the parent has never changed. So we set the > parent clock as oscclk before power gating and then set back the correct > parent clock after powering on a domain. > > Signed-off-by: Prathyush K <prathyush.k@samsung.com> > Signed-off-by: Andrew Bresticker <abrestic@chromium.org> > Signed-off-by: Arun Kumar K <arun.kk@samsung.com> > --- > This patch is posted for getting the opinion from all on what would > be the best possible solution to the issue at hand. > The issue is observed with multiple IPs like MFC, GSC, G2D, MSC etc. > where after a PD OFF-ON sequence, the parent clock gets reset to oscclk. > I would like to get the opinion from all on what would be the right > place to handle this. Either the clock re-parenting should be done > by all these individual IP drivers > OR > power-domain driver can handle this at a common place as is being done > in this patch. > > One more possible change I can do is to make a exynos5250 compatible for > the power-domain driver and get the extra clocks only for exynos5 onwards. > But since there are no errors being reported even if these clocks are not > provided, these changes are fully backward compatible with exynos4 also. > --- > .../bindings/arm/exynos/power_domain.txt | 18 +++++++ > arch/arm/mach-exynos/pm_domains.c | 56 +++++++++++++++++++- > 2 files changed, 73 insertions(+), 1 deletion(-) > > diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt > index 5216b41..2e19a9f 100644 > --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt > +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt > @@ -9,6 +9,16 @@ Required Properties: > - reg: physical base address of the controller and length of memory mapped > region. > > +Optional Properties: > +- clocks: List of clock handles. The parent clocks of the input clocks to the > + devices in this power domain are set to oscclk before power gating and > + restored back after powering on a domain. This is required for all domains > + which are powered on and off and not required for unused domains. > + The following clocks can be specified: > + - oscclk: oscillator clock. > + - clk(n): input clock to the devices in this power domain > + - pclk(n): parent clock of input clock to the devices in this power domain > + > Node of a device using power domains must have a samsung,power-domain property > defined with a phandle to respective power domain. > > @@ -19,6 +29,14 @@ Example: > reg = <0x10023C00 0x10>; > }; > > + mfc_pd: power-domain@10044060 { > + compatible = "samsung,exynos4210-pd"; > + reg = <0x10044060 0x20>; > + clocks = <&clock CLK_FIN_PLL>, <&clock MOUT_SW_ACLK333>, > + <&clock MOUT_USER_ACLK333>; > + clock-names = "oscclk", "pclk0", "clk0"; > + }; > + > Example of the node using power domain: > > node { > diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c > index fe6570e..e5fe76d 100644 > --- a/arch/arm/mach-exynos/pm_domains.c > +++ b/arch/arm/mach-exynos/pm_domains.c > @@ -17,6 +17,7 @@ > #include <linux/err.h> > #include <linux/slab.h> > #include <linux/pm_domain.h> > +#include <linux/clk.h> > #include <linux/delay.h> > #include <linux/of_address.h> > #include <linux/of_platform.h> > @@ -24,6 +25,8 @@ > > #include "regs-pmu.h" > > +#define MAX_CLK_PER_DOMAIN 4 > + > /* > * Exynos specific wrapper around the generic power domain > */ > @@ -32,6 +35,9 @@ struct exynos_pm_domain { > char const *name; > bool is_off; > struct generic_pm_domain pd; > + struct clk *oscclk; > + struct clk *clk[MAX_CLK_PER_DOMAIN]; > + struct clk *pclk[MAX_CLK_PER_DOMAIN]; > }; > > static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) > @@ -44,6 +50,18 @@ static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) > pd = container_of(domain, struct exynos_pm_domain, pd); > base = pd->base; > > + /* Set oscclk before powering off a domain*/ > + if (!power_on) { > + int i; > + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { > + if (!pd->clk[i]) > + break; > + if (clk_set_parent(pd->clk[i], pd->oscclk)) > + pr_info("%s: error setting oscclk as parent to clock %d\n", > + pd->name, i); > + } > + } > + > pwr = power_on ? S5P_INT_LOCAL_PWR_EN : 0; > __raw_writel(pwr, base); > > @@ -60,6 +78,19 @@ static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) > cpu_relax(); > usleep_range(80, 100); > } > + > + /* Restore clocks after powering on a domain*/ > + if (power_on) { > + int i; > + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { > + if (!pd->clk[i]) > + break; > + if (clk_set_parent(pd->clk[i], pd->pclk[i])) > + pr_info("%s: error setting parent to clock%d\n", > + pd->name, i); > + } > + } > + > return 0; > } > > @@ -152,9 +183,11 @@ static __init int exynos4_pm_init_power_domain(void) > > for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") { > struct exynos_pm_domain *pd; > - int on; > + int on, i; > + struct device *dev; > > pdev = of_find_device_by_node(np); > + dev = &pdev->dev; > > pd = kzalloc(sizeof(*pd), GFP_KERNEL); > if (!pd) { > @@ -170,6 +203,27 @@ static __init int exynos4_pm_init_power_domain(void) > pd->pd.power_on = exynos_pd_power_on; > pd->pd.of_node = np; > > + pd->oscclk = devm_clk_get(dev, "oscclk"); > + if (IS_ERR(pd->oscclk)) > + goto no_clk; > + > + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { > + struct clk *tmp, *tmp_parent; > + char clk_name[8]; > + > + snprintf(clk_name, sizeof(clk_name), "clk%d", i); > + tmp = devm_clk_get(dev, clk_name); > + if (IS_ERR(tmp)) > + break; > + snprintf(clk_name, sizeof(clk_name), "pclk%d", i); > + tmp_parent = devm_clk_get(dev, clk_name); > + if (IS_ERR(tmp_parent)) > + break; > + pd->clk[i] = tmp; > + pd->pclk[i] = tmp_parent; > + } > + > +no_clk: > platform_set_drvdata(pdev, pd); > > on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN; > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" 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/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt index 5216b41..2e19a9f 100644 --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt @@ -9,6 +9,16 @@ Required Properties: - reg: physical base address of the controller and length of memory mapped region. +Optional Properties: +- clocks: List of clock handles. The parent clocks of the input clocks to the + devices in this power domain are set to oscclk before power gating and + restored back after powering on a domain. This is required for all domains + which are powered on and off and not required for unused domains. + The following clocks can be specified: + - oscclk: oscillator clock. + - clk(n): input clock to the devices in this power domain + - pclk(n): parent clock of input clock to the devices in this power domain + Node of a device using power domains must have a samsung,power-domain property defined with a phandle to respective power domain. @@ -19,6 +29,14 @@ Example: reg = <0x10023C00 0x10>; }; + mfc_pd: power-domain@10044060 { + compatible = "samsung,exynos4210-pd"; + reg = <0x10044060 0x20>; + clocks = <&clock CLK_FIN_PLL>, <&clock MOUT_SW_ACLK333>, + <&clock MOUT_USER_ACLK333>; + clock-names = "oscclk", "pclk0", "clk0"; + }; + Example of the node using power domain: node { diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c index fe6570e..e5fe76d 100644 --- a/arch/arm/mach-exynos/pm_domains.c +++ b/arch/arm/mach-exynos/pm_domains.c @@ -17,6 +17,7 @@ #include <linux/err.h> #include <linux/slab.h> #include <linux/pm_domain.h> +#include <linux/clk.h> #include <linux/delay.h> #include <linux/of_address.h> #include <linux/of_platform.h> @@ -24,6 +25,8 @@ #include "regs-pmu.h" +#define MAX_CLK_PER_DOMAIN 4 + /* * Exynos specific wrapper around the generic power domain */ @@ -32,6 +35,9 @@ struct exynos_pm_domain { char const *name; bool is_off; struct generic_pm_domain pd; + struct clk *oscclk; + struct clk *clk[MAX_CLK_PER_DOMAIN]; + struct clk *pclk[MAX_CLK_PER_DOMAIN]; }; static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) @@ -44,6 +50,18 @@ static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) pd = container_of(domain, struct exynos_pm_domain, pd); base = pd->base; + /* Set oscclk before powering off a domain*/ + if (!power_on) { + int i; + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (!pd->clk[i]) + break; + if (clk_set_parent(pd->clk[i], pd->oscclk)) + pr_info("%s: error setting oscclk as parent to clock %d\n", + pd->name, i); + } + } + pwr = power_on ? S5P_INT_LOCAL_PWR_EN : 0; __raw_writel(pwr, base); @@ -60,6 +78,19 @@ static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on) cpu_relax(); usleep_range(80, 100); } + + /* Restore clocks after powering on a domain*/ + if (power_on) { + int i; + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + if (!pd->clk[i]) + break; + if (clk_set_parent(pd->clk[i], pd->pclk[i])) + pr_info("%s: error setting parent to clock%d\n", + pd->name, i); + } + } + return 0; } @@ -152,9 +183,11 @@ static __init int exynos4_pm_init_power_domain(void) for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") { struct exynos_pm_domain *pd; - int on; + int on, i; + struct device *dev; pdev = of_find_device_by_node(np); + dev = &pdev->dev; pd = kzalloc(sizeof(*pd), GFP_KERNEL); if (!pd) { @@ -170,6 +203,27 @@ static __init int exynos4_pm_init_power_domain(void) pd->pd.power_on = exynos_pd_power_on; pd->pd.of_node = np; + pd->oscclk = devm_clk_get(dev, "oscclk"); + if (IS_ERR(pd->oscclk)) + goto no_clk; + + for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) { + struct clk *tmp, *tmp_parent; + char clk_name[8]; + + snprintf(clk_name, sizeof(clk_name), "clk%d", i); + tmp = devm_clk_get(dev, clk_name); + if (IS_ERR(tmp)) + break; + snprintf(clk_name, sizeof(clk_name), "pclk%d", i); + tmp_parent = devm_clk_get(dev, clk_name); + if (IS_ERR(tmp_parent)) + break; + pd->clk[i] = tmp; + pd->pclk[i] = tmp_parent; + } + +no_clk: platform_set_drvdata(pdev, pd); on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN;