提交 c760569d 编写于 作者: P Prathyush K 提交者: Kukjin Kim

ARM: EXYNOS: Add support for clock handling in power domain

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. With this patch, while
powering off a domain, parent is set to oscclk and while powering back
on, its re-set to the correct parent which is as per the recommended
pd on/off sequence.
Signed-off-by: NPrathyush K <prathyush.k@samsung.com>
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Signed-off-by: NArun Kumar K <arun.kk@samsung.com>
Signed-off-by: NShaik Ameer Basha <shaik.ameer@samsung.com>
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
上级 be0b420a
......@@ -9,6 +9,18 @@ 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.
- clock-names: The following clocks can be specified:
- oscclk: Oscillator clock.
- pclkN, clkN: Pairs of parent of input clock and input clock to the
devices in this power domain. Maximum of 4 pairs (N = 0 to 3)
are supported currently.
Node of a device using power domains must have a samsung,power-domain property
defined with a phandle to respective power domain.
......@@ -19,6 +31,14 @@ Example:
reg = <0x10023C00 0x10>;
};
mfc_pd: power-domain@10044060 {
compatible = "samsung,exynos4210-pd";
reg = <0x10044060 0x20>;
clocks = <&clock CLK_FIN_PLL>, <&clock CLK_MOUT_SW_ACLK333>,
<&clock CLK_MOUT_USER_ACLK333>;
clock-names = "oscclk", "pclk0", "clk0";
};
Example of the node using power domain:
node {
......
......@@ -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 +50,19 @@ 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 (IS_ERR(pd->clk[i]))
break;
if (clk_set_parent(pd->clk[i], pd->oscclk))
pr_err("%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 +79,20 @@ 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 (IS_ERR(pd->clk[i]))
break;
if (clk_set_parent(pd->clk[i], pd->pclk[i]))
pr_err("%s: error setting parent to clock%d\n",
pd->name, i);
}
}
return 0;
}
......@@ -152,9 +185,11 @@ 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 +205,30 @@ static __init int exynos4_pm_init_power_domain(void)
pd->pd.power_on = exynos_pd_power_on;
pd->pd.of_node = np;
pd->oscclk = clk_get(dev, "oscclk");
if (IS_ERR(pd->oscclk))
goto no_clk;
for (i = 0; i < MAX_CLK_PER_DOMAIN; i++) {
char clk_name[8];
snprintf(clk_name, sizeof(clk_name), "clk%d", i);
pd->clk[i] = clk_get(dev, clk_name);
if (IS_ERR(pd->clk[i]))
break;
snprintf(clk_name, sizeof(clk_name), "pclk%d", i);
pd->pclk[i] = clk_get(dev, clk_name);
if (IS_ERR(pd->pclk[i])) {
clk_put(pd->clk[i]);
pd->clk[i] = ERR_PTR(-EINVAL);
break;
}
}
if (IS_ERR(pd->clk[0]))
clk_put(pd->oscclk);
no_clk:
platform_set_drvdata(pdev, pd);
on = __raw_readl(pd->base + 0x4) & S5P_INT_LOCAL_PWR_EN;
......
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