This driver is a simple muxing driver that controls the I2S's clock input by using syscon/regmap to change the parrent. The available inputs can be Peripheral clock and Generated clock.
Signed-off-by: Codrin Ciubotariu codrin.ciubotariu@microchip.com --- arch/arm/mach-at91/Kconfig | 4 ++ drivers/clk/at91/Makefile | 1 + drivers/clk/at91/clk-i2s-mux.c | 117 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 122 insertions(+) create mode 100644 drivers/clk/at91/clk-i2s-mux.c
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
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.o diff --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; +}; + +#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 = { + .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; + + 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; +} + +static void __init of_sama5d2_clk_i2s_mux_setup(struct device_node *np) +{ + struct regmap *regmap_sfr; + u32 bus_id; + const char *parent_names[2]; + struct device_node *i2s_mux_np; + struct clk_hw *hw; + int ret; + + regmap_sfr = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr"); + if (IS_ERR(regmap_sfr)) + return; + + for_each_child_of_node(np, i2s_mux_np) { + if (of_property_read_u32(i2s_mux_np, "reg", &bus_id)) + continue; + + if (bus_id > I2S_BUS_NR) + continue; + + ret = of_clk_parent_fill(i2s_mux_np, parent_names, 2); + if (ret != 2) + continue; + + hw = at91_clk_i2s_mux_register(regmap_sfr, i2s_mux_np->name, + parent_names, 2, bus_id); + if (IS_ERR(hw)) + continue; + + of_clk_add_hw_provider(i2s_mux_np, of_clk_hw_simple_get, hw); + } +} + +CLK_OF_DECLARE(sama5d2_clk_i2s_mux, "atmel,sama5d2-clk-i2s-mux", + of_sama5d2_clk_i2s_mux_setup);