Add Clock Domain support to the Clock Pulse Generator (CPG) Module Stop
(MSTP) Clocks driver using the generic PM Domain. This allows to
power-manage the module clocks of SoC devices that are part of the
CPG/MSTP Clock Domain using Runtime PM, or for system suspend/resume.
SoC devices that are part of the CPG/MSTP Clock Domain and can be
power-managed through an MSTP clock should be tagged in DT with a
proper "power-domains" property.
The CPG/MSTP Clock Domain code will scan such devices for clocks that
are suitable for power-managing the device, by looking for a clock that
is compatible with "renesas,cpg-mstp-clocks".
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Reviewed-by: Kevin Hilman <khilman@xxxxxxxxxx>
---
v3:
- Add Acked-by,
- Use "CPG/MSTP Clock Domain" instead of "CPG Clock Domain",
- Drop bogus addition of #includes to clk-rcar-gen2.c,
- Call pm_clk_destroy() from cpg_mstp_detach_dev() only if
cpg_mstp_attach_dev() actually added a clock,
v2:
- Add Acked-by and Reviewed-by,
- Move core CPG Clock Domain code from the R-Car Gen2 driver to the
CPG MSTP Clock driver, as it's generic, and can be used on other
Renesas SoCs that have a CPG/MSTP block,
- Scan for an MSTP clock instead of using the first clock tied to the
device (con_id NULL),
- Extract R-Car Gen2 specifics to a separate patch.
---
drivers/clk/shmobile/clk-mstp.c | 86 +++++++++++++++++++++++++++++++++++++++++
include/linux/clk/shmobile.h | 12 ++++++
2 files changed, 98 insertions(+)
diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c
index 2d2fe773ac8168f9..9b4451304f5732d4 100644
--- a/drivers/clk/shmobile/clk-mstp.c
+++ b/drivers/clk/shmobile/clk-mstp.c
@@ -2,6 +2,7 @@
* R-Car MSTP clocks
*
* Copyright (C) 2013 Ideas On Board SPRL
+ * Copyright (C) 2015 Glider bvba
*
* Contact: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
*
@@ -12,9 +13,13 @@
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
+#include <linux/clk/shmobile.h>
+#include <linux/device.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
+#include <linux/pm_clock.h>
+#include <linux/pm_domain.h>
#include <linux/spinlock.h>
/*
@@ -236,3 +241,84 @@ static void __init cpg_mstp_clocks_init(struct device_node *np)
of_clk_add_provider(np, of_clk_src_onecell_get, &group->data);
}
CLK_OF_DECLARE(cpg_mstp_clks, "renesas,cpg-mstp-clocks", cpg_mstp_clocks_init);
+
+
+#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
+int cpg_mstp_attach_dev(struct generic_pm_domain *domain, struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct of_phandle_args clkspec;
+ struct clk *clk;
+ int i = 0;
+ int error;
+
+ while (!of_parse_phandle_with_args(np, "clocks", "#clock-cells", i,
+ &clkspec)) {
+ if (of_device_is_compatible(clkspec.np,
+ "renesas,cpg-mstp-clocks"))
+ goto found;
+
+ of_node_put(clkspec.np);
+ i++;
+ }
+
+ return 0;
+
+found:
+ clk = of_clk_get_from_provider(&clkspec);
+ of_node_put(clkspec.np);
+
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ error = pm_clk_create(dev);
+ if (error) {
+ dev_err(dev, "pm_clk_create failed %d\n", error);
+ goto fail_put;
+ }
+
+ error = pm_clk_add_clk(dev, clk);
+ if (error) {
+ dev_err(dev, "pm_clk_add_clk %pC failed %d\n", clk, error);
+ goto fail_destroy;
+ }
+
+ return 0;
+
+fail_destroy:
+ pm_clk_destroy(dev);
+fail_put:
+ clk_put(clk);
+ return error;
+}
+
+void cpg_mstp_detach_dev(struct generic_pm_domain *domain, struct device *dev)
+{
+ if (!list_empty(&dev->power.subsys_data->clock_list))
+ pm_clk_destroy(dev);
+}
+
+void __init cpg_mstp_add_clk_domain(struct device_node *np)
+{
+ struct generic_pm_domain *pd;
+ u32 ncells;
+
+ if (of_property_read_u32(np, "#power-domain-cells", &ncells)) {
+ pr_warn("%s lacks #power-domain-cells\n", np->full_name);
+ return;
+ }
+
+ pd = kzalloc(sizeof(*pd), GFP_KERNEL);
+ if (!pd)
+ return;
+
+ pd->name = np->name;
+
+ pd->flags = GENPD_FLAG_PM_CLK;
+ pm_genpd_init(pd, &simple_qos_governor, false);
+ pd->attach_dev = cpg_mstp_attach_dev;
+ pd->detach_dev = cpg_mstp_detach_dev;
+
+ of_genpd_add_provider_simple(np, pd);
+}
+#endif /* !CONFIG_PM_GENERIC_DOMAINS_OF */
diff --git a/include/linux/clk/shmobile.h b/include/linux/clk/shmobile.h
index 63a8159c4e64153d..cb19cc1865ca5cfb 100644
--- a/include/linux/clk/shmobile.h
+++ b/include/linux/clk/shmobile.h
@@ -16,8 +16,20 @@
#include <linux/types.h>
+struct device;
+struct device_node;
+struct generic_pm_domain;
+
void r8a7778_clocks_init(u32 mode);
void r8a7779_clocks_init(u32 mode);
void rcar_gen2_clocks_init(u32 mode);
+#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
+void cpg_mstp_add_clk_domain(struct device_node *np);
+int cpg_mstp_attach_dev(struct generic_pm_domain *domain, struct device *dev);
+void cpg_mstp_detach_dev(struct generic_pm_domain *domain, struct device *dev);
+#else
+static inline void cpg_mstp_add_clk_domain(struct device_node *np) {}
+#endif
+
#endif
--
1.9.1
--
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