[PATCH v4 2/7] clk: at91: add I2S clock mux driver
From: sboyd@kernel.org (Stephen Boyd)
Date: 2018-05-31 15:26:46
Also in:
alsa-devel, linux-clk, linux-devicetree, lkml
Quoting Codrin Ciubotariu (2018-05-25 05:34:23)
This driver is a simple muxing driver that controls the I2S's clock input by using syscon/regmap to change the parrent.
s/parrent/parent/
The available inputs can be Peripheral clock and Generated clock.
Why capitalize peripheral and generated?
quoted hunk ↗ jump to hunk
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com> ---diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig index 1254bf9..903f23c 100644 --- a/arch/arm/mach-at91/Kconfig +++ b/arch/arm/mach-at91/Kconfig@@ -27,6 +27,7 @@ config SOC_SAMA5D2 select HAVE_AT91_H32MX select HAVE_AT91_GENERATED_CLK select HAVE_AT91_AUDIO_PLL + select HAVE_AT91_I2S_MUX_CLK select PINCTRL_AT91PIO4 help Select this if ou are using one of Microchip's SAMA5D2 family SoC.@@ -129,6 +130,9 @@ config HAVE_AT91_GENERATED_CLK config HAVE_AT91_AUDIO_PLL bool +config HAVE_AT91_I2S_MUX_CLK + bool + config SOC_SAM_V4_V5 bool
I guess this is OK.
quoted hunk ↗ jump to hunk
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index 082596f..facc169 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile@@ -13,3 +13,4 @@ obj-$(CONFIG_HAVE_AT91_USB_CLK) += clk-usb.o obj-$(CONFIG_HAVE_AT91_SMD) += clk-smd.o obj-$(CONFIG_HAVE_AT91_H32MX) += clk-h32mx.o obj-$(CONFIG_HAVE_AT91_GENERATED_CLK) += clk-generated.o +obj-$(CONFIG_HAVE_AT91_I2S_MUX_CLK) += clk-i2s-mux.odiff --git a/drivers/clk/at91/clk-i2s-mux.c b/drivers/clk/at91/clk-i2s-mux.c new file mode 100644 index 0000000..2d56ded --- /dev/null +++ b/drivers/clk/at91/clk-i2s-mux.c@@ -0,0 +1,117 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2018 Microchip Technology Inc, + * Codrin Ciubotariu <codrin.ciubotariu@microchip.com> + * + * + */ + +#include <linux/clk-provider.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include <soc/at91/atmel-sfr.h> + +#define I2S_BUS_NR 2 + +struct clk_i2s_mux { + struct clk_hw hw; + struct regmap *regmap; + u32 bus_id;
Can be a u8?
+};
+
+#define to_clk_i2s_mux(hw) container_of(hw, struct clk_i2s_mux, hw)
+
+static u8 clk_i2s_mux_get_parent(struct clk_hw *hw)
+{
+ struct clk_i2s_mux *mux = to_clk_i2s_mux(hw);
+ u32 val;
+
+ regmap_read(mux->regmap, AT91_SFR_I2SCLKSEL, &val);
+
+ return (val & BIT(mux->bus_id)) >> mux->bus_id;
+}
+
+static int clk_i2s_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct clk_i2s_mux *mux = to_clk_i2s_mux(hw);
+
+ return regmap_update_bits(mux->regmap, AT91_SFR_I2SCLKSEL,
+ BIT(mux->bus_id), index << mux->bus_id);
+}
+
+const struct clk_ops clk_i2s_mux_ops = {static?
+ .get_parent = clk_i2s_mux_get_parent,
+ .set_parent = clk_i2s_mux_set_parent,
+ .determine_rate = __clk_mux_determine_rate,
+};
+
+static struct clk_hw * __init
+at91_clk_i2s_mux_register(struct regmap *regmap, const char *name,
+ const char * const *parent_names,
+ unsigned int num_parents, u32 bus_id)
+{
+ struct clk_init_data init = {};
+ struct clk_i2s_mux *i2s_ck;
+ int ret;
+
+ i2s_ck = kzalloc(sizeof(*i2s_ck), GFP_KERNEL);
+ if (!i2s_ck)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &clk_i2s_mux_ops;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+ init.flags = CLK_IGNORE_UNUSED;Really? Why?
+
+ i2s_ck->hw.init = &init;
+ i2s_ck->bus_id = bus_id;
+ i2s_ck->regmap = regmap;
+
+ ret = clk_hw_register(NULL, &i2s_ck->hw);
+ if (ret) {
+ kfree(i2s_ck);
+ return ERR_PTR(ret);
+ }
+
+ return &i2s_ck->hw;
+}