diff options
Diffstat (limited to 'drivers/clk/renesas/clk-div6.c')
| -rw-r--r-- | drivers/clk/renesas/clk-div6.c | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/drivers/clk/renesas/clk-div6.c b/drivers/clk/renesas/clk-div6.c index 3e0040c0ac87..151336d2ba59 100644 --- a/drivers/clk/renesas/clk-div6.c +++ b/drivers/clk/renesas/clk-div6.c @@ -14,8 +14,10 @@ #include <linux/init.h> #include <linux/io.h> #include <linux/kernel.h> +#include <linux/notifier.h> #include <linux/of.h> #include <linux/of_address.h> +#include <linux/pm.h> #include <linux/slab.h> #include "clk-div6.h" @@ -32,6 +34,7 @@ * @src_shift: Shift to access the register bits to select the parent clock * @src_width: Number of register bits to select the parent clock (may be 0) * @parents: Array to map from valid parent clocks indices to hardware indices + * @nb: Notifier block to save/restore clock state for system resume */ struct div6_clock { struct clk_hw hw; @@ -40,6 +43,7 @@ struct div6_clock { u32 src_shift; u32 src_width; u8 *parents; + struct notifier_block nb; }; #define to_div6_clock(_hw) container_of(_hw, struct div6_clock, hw) @@ -176,6 +180,29 @@ static const struct clk_ops cpg_div6_clock_ops = { .set_rate = cpg_div6_clock_set_rate, }; +static int cpg_div6_clock_notifier_call(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct div6_clock *clock = container_of(nb, struct div6_clock, nb); + + switch (action) { + case PM_EVENT_RESUME: + /* + * TODO: This does not yet support DIV6 clocks with multiple + * parents, as the parent selection bits are not restored. + * Fortunately so far such DIV6 clocks are found only on + * R/SH-Mobile SoCs, while the resume functionality is only + * needed on R-Car Gen3. + */ + if (__clk_get_enable_count(clock->hw.clk)) + cpg_div6_clock_enable(&clock->hw); + else + cpg_div6_clock_disable(&clock->hw); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} /** * cpg_div6_register - Register a DIV6 clock @@ -183,11 +210,13 @@ static const struct clk_ops cpg_div6_clock_ops = { * @num_parents: Number of parent clocks of the DIV6 clock (1, 4, or 8) * @parent_names: Array containing the names of the parent clocks * @reg: Mapped register used to control the DIV6 clock + * @notifiers: Optional notifier chain to save/restore state for system resume */ struct clk * __init cpg_div6_register(const char *name, unsigned int num_parents, const char **parent_names, - void __iomem *reg) + void __iomem *reg, + struct raw_notifier_head *notifiers) { unsigned int valid_parents; struct clk_init_data init; @@ -258,6 +287,11 @@ struct clk * __init cpg_div6_register(const char *name, if (IS_ERR(clk)) goto free_parents; + if (notifiers) { + clock->nb.notifier_call = cpg_div6_clock_notifier_call; + raw_notifier_chain_register(notifiers, &clock->nb); + } + return clk; free_parents: @@ -301,7 +335,7 @@ static void __init cpg_div6_clock_init(struct device_node *np) for (i = 0; i < num_parents; i++) parent_names[i] = of_clk_get_parent_name(np, i); - clk = cpg_div6_register(clk_name, num_parents, parent_names, reg); + clk = cpg_div6_register(clk_name, num_parents, parent_names, reg, NULL); if (IS_ERR(clk)) { pr_err("%s: failed to register %s DIV6 clock (%ld)\n", __func__, np->name, PTR_ERR(clk)); |