regmap: mmio: Add function to attach a clock

regmap_init_mmio_clk allows to specify a clock that needs to be enabled
while accessing the registers.

However, that clock is retrieved through its clock ID, which means it will
lookup that clock based on the current device that registers the regmap,
and, in the DT case, will only look in that device OF node.

This might be problematic if the clock to enable is stored in another node.
Let's add a function that allows to attach a clock that has already been
retrieved to a regmap in order to fix this.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c
index 5189fd6182f6c6126b21b1d6b3e25f760d4df290..5cadfd3394d8a31e726eaacd5166e1c83bf8875d 100644 (file)
--- a/drivers/base/regmap/regmap-mmio.c
+++ b/drivers/base/regmap/regmap-mmio.c
@@ -28,6 +28,8 @@
 struct regmap_mmio_context {
        void __iomem *regs;
        unsigned val_bytes;
+
+       bool attached_clk;
        struct clk *clk;
 
        void (*reg_write)(struct regmap_mmio_context *ctx,
@@ -363,4 +365,26 @@ struct regmap *__devm_regmap_init_mmio_clk(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(__devm_regmap_init_mmio_clk);
 
+int regmap_mmio_attach_clk(struct regmap *map, struct clk *clk)
+{
+       struct regmap_mmio_context *ctx = map->bus_context;
+
+       ctx->clk = clk;
+       ctx->attached_clk = true;
+
+       return clk_prepare(ctx->clk);
+}
+EXPORT_SYMBOL_GPL(regmap_mmio_attach_clk);
+
+void regmap_mmio_detach_clk(struct regmap *map)
+{
+       struct regmap_mmio_context *ctx = map->bus_context;
+
+       clk_unprepare(ctx->clk);
+
+       ctx->attached_clk = false;
+       ctx->clk = NULL;
+}
+EXPORT_SYMBOL_GPL(regmap_mmio_detach_clk);
+
 MODULE_LICENSE("GPL v2");

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 6a3aeba40e9e402e44293979cc1978d30020e211..5f7ad0552c0381e9ffe4136cf77cdb050200231f 100644 (file)
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -21,6 +21,7 @@
 #include <linux/lockdep.h>
 
 struct module;
+struct clk;
 struct device;
 struct i2c_client;
 struct irq_domain;
@@ -905,6 +906,8 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
        __regmap_lockdep_wrapper(__devm_regmap_init_sdw, #config,       \
                                sdw, config)
 
+int regmap_mmio_attach_clk(struct regmap *map, struct clk *clk);
+void regmap_mmio_detach_clk(struct regmap *map);
 void regmap_exit(struct regmap *map);
 int regmap_reinit_cache(struct regmap *map,
                        const struct regmap_config *config);