diff mbox

[v4,2/7] clk: at91: add I2S clock mux driver

Message ID 1527251668-31396-3-git-send-email-codrin.ciubotariu@microchip.com (mailing list archive)
State New, archived
Headers show

Commit Message

Codrin Ciubotariu May 25, 2018, 12:34 p.m. UTC
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

Comments

Stephen Boyd May 31, 2018, 3:26 p.m. UTC | #1
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?

> 
> 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.

> 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;

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;
> +}
Codrin Ciubotariu June 4, 2018, 8:20 a.m. UTC | #2
On 31.05.2018 18:26, Stephen Boyd wrote:
> 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/

I will fix it.

> 
>> The available inputs can be Peripheral clock and Generated clock.
> 
> Why capitalize peripheral and generated?

In DS, at I2S block these clocks appear defined with capital letters... 
I will fix it.

> 
>>
>> 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.
> 
>> 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;
> 
> Can be a u8?

I think so, I will cast out_value parameter of of_property_read_u32() to 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?

Yes, I will fix it.

> 
>> +       .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?

I am thinking that there is no need to gate this clock, since there is 
no way to gate this clock in HW.

> 
>> +
>> +       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;
>> +}

Thank you for your review. I will wait a few more days for more comments 
on this series and send a V5 afterwards.

Best regards,
Codrin
Stephen Boyd June 12, 2018, 4:33 p.m. UTC | #3
Quoting Codrin Ciubotariu (2018-06-04 01:20:29)
> On 31.05.2018 18:26, Stephen Boyd wrote:
> > Quoting Codrin Ciubotariu (2018-05-25 05:34:23)
> > 
> >> +       .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?
> 
> I am thinking that there is no need to gate this clock, since there is 
> no way to gate this clock in HW.

This flag is not necessary if the clk can't be gated via hardware
control registers. Please remove the flag.
diff mbox

Patch

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);