[PATCH v4 1/4] dt-bindings: Document img,boston-clock binding

[PATCH v4 1/4] dt-bindings: Document img,boston-clock binding

[Paul Burton]

Add device tree binding documentation for the clocks provided by the
MIPS Boston development board from Imagination Technologies, and a
header file describing the available clocks for use by device trees &
driver.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: devicetree@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-mips@linux-mips.org

---

Changes in v4:
- Move img,boston-clock node under platform register syscon node.
- Add MAINTAINERS entry.

Changes in v3: None

Changes in v2:
- Add BOSTON_CLK_INPUT to expose the input clock.

 .../devicetree/bindings/clock/img,boston-clock.txt | 31 ++++++++++++++++++++++
 MAINTAINERS                                        |  7 +++++
 include/dt-bindings/clock/boston-clock.h           | 14 ++++++++++
 3 files changed, 52 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/img,boston-clock.txt
 create mode 100644 include/dt-bindings/clock/boston-clock.h

diff --git a/Documentation/devicetree/bindings/clock/img,boston-clock.txt b/Documentation/devicetree/bindings/clock/img,boston-clock.txt
new file mode 100644
index 000000000000..7bc5e9ffb624
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/img,boston-clock.txt
@@ -0,0 +1,31 @@
+Binding for Imagination Technologies MIPS Boston clock sources.
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+The device node must be a child node of the syscon node corresponding to the
+Boston system's platform registers.
+
+Required properties:
+- compatible : Should be "img,boston-clock".
+- #clock-cells : Should be set to 1.
+  Values available for clock consumers can be found in the header file:
+    <dt-bindings/clock/boston-clock.h>
+
+Example:
+
+	system-controller@17ffd000 {
+		compatible = "img,boston-platform-regs", "syscon";
+		reg = <0x17ffd000 0x1000>;
+
+		clk_boston: clock {
+			compatible = "img,boston-clock";
+			#clock-cells = <1>;
+		};
+	};
+
+	uart0: uart@17ffe000 {
+		/* ... */
+		clocks = <&clk_boston BOSTON_CLK_SYS>;
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index 053c3bdd1fe5..481fc6d54ca4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8499,6 +8499,13 @@ F:	arch/mips/include/asm/mach-loongson32/
 F:	drivers/*/*loongson1*
 F:	drivers/*/*/*loongson1*
 
+MIPS BOSTON DEVELOPMENT BOARD
+M:	Paul Burton <paul.burton@imgtec.com>
+L:	linux-mips@linux-mips.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/clock/img,boston-clock.txt
+F:	include/dt-bindings/clock/boston-clock.h
+
 MIROSOUND PCM20 FM RADIO RECEIVER DRIVER
 M:	Hans Verkuil <hverkuil@xs4all.nl>
 L:	linux-media@vger.kernel.org
diff --git a/include/dt-bindings/clock/boston-clock.h b/include/dt-bindings/clock/boston-clock.h
new file mode 100644
index 000000000000..a6f009821137
--- /dev/null
+++ b/include/dt-bindings/clock/boston-clock.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__
+#define __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__
+
+#define BOSTON_CLK_INPUT 0
+#define BOSTON_CLK_SYS 1
+#define BOSTON_CLK_CPU 2
+
+#endif /* __DT_BINDINGS_CLOCK_BOSTON_CLOCK_H__ */
-- 
2.13.0

[PATCH v4 2/4] clk: boston: Add a driver for MIPS Boston board clocks

[Paul Burton]

Add a driver for the clocks provided by the MIPS Boston board from
Imagination Technologies. 2 clocks are provided - the system clock & the
CPU clock - and each is a simple fixed rate clock whose frequency can be
determined by reading a register provided by the board.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-mips@linux-mips.org

---

Changes in v4:
- Adjust to expect the parent node to be the syscon.
- Update MAINTAINERS entry.

Changes in v3: None

Changes in v2:
- Support BOSTON_CLK_INPUT.
- Register clocks with clk_register_fixed_rate during boot, removing need for clk_ops.
- s/uint32_t/u32/.
- Move driver to a vendor directory.

 MAINTAINERS                     |   1 +
 drivers/clk/Kconfig             |   1 +
 drivers/clk/Makefile            |   1 +
 drivers/clk/imgtec/Kconfig      |  10 ++++
 drivers/clk/imgtec/Makefile     |   1 +
 drivers/clk/imgtec/clk-boston.c | 101 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 115 insertions(+)
 create mode 100644 drivers/clk/imgtec/Kconfig
 create mode 100644 drivers/clk/imgtec/Makefile
 create mode 100644 drivers/clk/imgtec/clk-boston.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 481fc6d54ca4..75284ef8d06c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8504,6 +8504,7 @@ M:	Paul Burton <paul.burton@imgtec.com>
 L:	linux-mips@linux-mips.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/clock/img,boston-clock.txt
+F:	drivers/clk/imgtec/clk-boston.c
 F:	include/dt-bindings/clock/boston-clock.h
 
 MIROSOUND PCM20 FM RADIO RECEIVER DRIVER
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 36cfea38135f..251a22139e73 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -219,6 +219,7 @@ config COMMON_CLK_VC5
 
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
+source "drivers/clk/imgtec/Kconfig"
 source "drivers/clk/mediatek/Kconfig"
 source "drivers/clk/meson/Kconfig"
 source "drivers/clk/mvebu/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index c19983afcb81..a4a7c5df8b93 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -59,6 +59,7 @@ obj-y					+= bcm/
 obj-$(CONFIG_ARCH_BERLIN)		+= berlin/
 obj-$(CONFIG_H8300)			+= h8300/
 obj-$(CONFIG_ARCH_HISI)			+= hisilicon/
+obj-y					+= imgtec/
 obj-$(CONFIG_ARCH_MXC)			+= imx/
 obj-$(CONFIG_MACH_INGENIC)		+= ingenic/
 obj-$(CONFIG_COMMON_CLK_KEYSTONE)	+= keystone/
diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig
new file mode 100644
index 000000000000..c2ea745928e4
--- /dev/null
+++ b/drivers/clk/imgtec/Kconfig
@@ -0,0 +1,10 @@
+config COMMON_CLK_BOSTON
+	bool "Clock driver for MIPS Boston boards"
+	depends on MIPS || COMPILE_TEST
+	depends on OF
+	select MFD_SYSCON
+	---help---
+	  Enable this to support the system & CPU clocks on the MIPS Boston
+	  development board from Imagination Technologies. These are simple
+	  fixed rate clocks whose rate is determined by reading a platform
+	  provided register.
diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile
new file mode 100644
index 000000000000..ac779b8c22f2
--- /dev/null
+++ b/drivers/clk/imgtec/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_COMMON_CLK_BOSTON)		+= clk-boston.o
diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c
new file mode 100644
index 000000000000..98bb0b764d15
--- /dev/null
+++ b/drivers/clk/imgtec/clk-boston.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2016-2017 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+
+#include <dt-bindings/clock/boston-clock.h>
+
+#define BOSTON_PLAT_MMCMDIV		0x30
+# define BOSTON_PLAT_MMCMDIV_CLK0DIV	(0xff << 0)
+# define BOSTON_PLAT_MMCMDIV_INPUT	(0xff << 8)
+# define BOSTON_PLAT_MMCMDIV_MUL	(0xff << 16)
+# define BOSTON_PLAT_MMCMDIV_CLK1DIV	(0xff << 24)
+
+#define BOSTON_CLK_COUNT 3
+
+struct clk_boston_state {
+	struct clk *clks[BOSTON_CLK_COUNT];
+	struct clk_onecell_data onecell_data;
+};
+
+static u32 ext_field(u32 val, u32 mask)
+{
+	return (val & mask) >> (ffs(mask) - 1);
+}
+
+static void __init clk_boston_setup(struct device_node *np)
+{
+	unsigned long in_freq, cpu_freq, sys_freq;
+	uint mmcmdiv, mul, cpu_div, sys_div;
+	struct clk_boston_state *state;
+	struct regmap *regmap;
+	struct clk *clk;
+	int err;
+
+	regmap = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(regmap)) {
+		pr_err("failed to find regmap\n");
+		return;
+	}
+
+	err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
+	if (err) {
+		pr_err("failed to read mmcm_div register: %d\n", err);
+		return;
+	}
+
+	in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
+	mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
+
+	sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
+	sys_freq = mult_frac(in_freq, mul, sys_div);
+
+	cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
+	cpu_freq = mult_frac(in_freq, mul, cpu_div);
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return;
+
+	clk = clk_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
+	if (IS_ERR(clk)) {
+		pr_err("failed to register input clock: %ld\n", PTR_ERR(clk));
+		return;
+	}
+	state->clks[BOSTON_CLK_INPUT] = clk;
+
+	clk = clk_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
+	if (IS_ERR(clk)) {
+		pr_err("failed to register sys clock: %ld\n", PTR_ERR(clk));
+		return;
+	}
+	state->clks[BOSTON_CLK_SYS] = clk;
+
+	clk = clk_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
+	if (IS_ERR(clk)) {
+		pr_err("failed to register cpu clock: %ld\n", PTR_ERR(clk));
+		return;
+	}
+	state->clks[BOSTON_CLK_CPU] = clk;
+
+	state->onecell_data.clks = state->clks;
+	state->onecell_data.clk_num = BOSTON_CLK_COUNT;
+
+	err = of_clk_add_provider(np, of_clk_src_onecell_get,
+				  &state->onecell_data);
+	if (err)
+		pr_err("failed to add DT provider: %d\n", err);
+}
+CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);
-- 
2.13.0

Re: [PATCH v4 1/4] dt-bindings: Document img,boston-clock binding

[Rob Herring]

On Fri, Jun 02, 2017 at 11:20:00AM -0700, Paul Burton wrote:
> Add device tree binding documentation for the clocks provided by the
> MIPS Boston development board from Imagination Technologies, and a
> header file describing the available clocks for use by device trees &
> driver.
> 
> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: devicetree@vger.kernel.org
> Cc: linux-clk@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> 
> ---
> 
> Changes in v4:
> - Move img,boston-clock node under platform register syscon node.
> - Add MAINTAINERS entry.
> 
> Changes in v3: None
> 
> Changes in v2:
> - Add BOSTON_CLK_INPUT to expose the input clock.
> 
>  .../devicetree/bindings/clock/img,boston-clock.txt | 31 ++++++++++++++++++++++
>  MAINTAINERS                                        |  7 +++++
>  include/dt-bindings/clock/boston-clock.h           | 14 ++++++++++
>  3 files changed, 52 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/img,boston-clock.txt
>  create mode 100644 include/dt-bindings/clock/boston-clock.h

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v4 2/4] clk: boston: Add a driver for MIPS Boston board clocks

[Ralf Baechle]

Ping?

   Ralf

On Fri, Jun 02, 2017 at 11:20:01AM -0700, Paul Burton wrote:

> Add a driver for the clocks provided by the MIPS Boston board from
> Imagination Technologies. 2 clocks are provided - the system clock & the
> CPU clock - and each is a simple fixed rate clock whose frequency can be
> determined by reading a register provided by the board.
> 
> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Stephen Boyd <sboyd@codeaurora.org>
> Cc: linux-clk@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> 
> ---
> 
> Changes in v4:
> - Adjust to expect the parent node to be the syscon.
> - Update MAINTAINERS entry.
> 
> Changes in v3: None
> 
> Changes in v2:
> - Support BOSTON_CLK_INPUT.
> - Register clocks with clk_register_fixed_rate during boot, removing need for clk_ops.
> - s/uint32_t/u32/.
> - Move driver to a vendor directory.
> 
>  MAINTAINERS                     |   1 +
>  drivers/clk/Kconfig             |   1 +
>  drivers/clk/Makefile            |   1 +
>  drivers/clk/imgtec/Kconfig      |  10 ++++
>  drivers/clk/imgtec/Makefile     |   1 +
>  drivers/clk/imgtec/clk-boston.c | 101 ++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 115 insertions(+)
>  create mode 100644 drivers/clk/imgtec/Kconfig
>  create mode 100644 drivers/clk/imgtec/Makefile
>  create mode 100644 drivers/clk/imgtec/clk-boston.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 481fc6d54ca4..75284ef8d06c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8504,6 +8504,7 @@ M:	Paul Burton <paul.burton@imgtec.com>
>  L:	linux-mips@linux-mips.org
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/clock/img,boston-clock.txt
> +F:	drivers/clk/imgtec/clk-boston.c
>  F:	include/dt-bindings/clock/boston-clock.h
>  
>  MIROSOUND PCM20 FM RADIO RECEIVER DRIVER
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 36cfea38135f..251a22139e73 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -219,6 +219,7 @@ config COMMON_CLK_VC5
>  
>  source "drivers/clk/bcm/Kconfig"
>  source "drivers/clk/hisilicon/Kconfig"
> +source "drivers/clk/imgtec/Kconfig"
>  source "drivers/clk/mediatek/Kconfig"
>  source "drivers/clk/meson/Kconfig"
>  source "drivers/clk/mvebu/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index c19983afcb81..a4a7c5df8b93 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -59,6 +59,7 @@ obj-y					+= bcm/
>  obj-$(CONFIG_ARCH_BERLIN)		+= berlin/
>  obj-$(CONFIG_H8300)			+= h8300/
>  obj-$(CONFIG_ARCH_HISI)			+= hisilicon/
> +obj-y					+= imgtec/
>  obj-$(CONFIG_ARCH_MXC)			+= imx/
>  obj-$(CONFIG_MACH_INGENIC)		+= ingenic/
>  obj-$(CONFIG_COMMON_CLK_KEYSTONE)	+= keystone/
> diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig
> new file mode 100644
> index 000000000000..c2ea745928e4
> --- /dev/null
> +++ b/drivers/clk/imgtec/Kconfig
> @@ -0,0 +1,10 @@
> +config COMMON_CLK_BOSTON
> +	bool "Clock driver for MIPS Boston boards"
> +	depends on MIPS || COMPILE_TEST
> +	depends on OF
> +	select MFD_SYSCON
> +	---help---
> +	  Enable this to support the system & CPU clocks on the MIPS Boston
> +	  development board from Imagination Technologies. These are simple
> +	  fixed rate clocks whose rate is determined by reading a platform
> +	  provided register.
> diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile
> new file mode 100644
> index 000000000000..ac779b8c22f2
> --- /dev/null
> +++ b/drivers/clk/imgtec/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_COMMON_CLK_BOSTON)		+= clk-boston.o
> diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c
> new file mode 100644
> index 000000000000..98bb0b764d15
> --- /dev/null
> +++ b/drivers/clk/imgtec/clk-boston.c
> @@ -0,0 +1,101 @@
> +/*
> + * Copyright (C) 2016-2017 Imagination Technologies
> + * Author: Paul Burton <paul.burton@imgtec.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +
> +#include <dt-bindings/clock/boston-clock.h>
> +
> +#define BOSTON_PLAT_MMCMDIV		0x30
> +# define BOSTON_PLAT_MMCMDIV_CLK0DIV	(0xff << 0)
> +# define BOSTON_PLAT_MMCMDIV_INPUT	(0xff << 8)
> +# define BOSTON_PLAT_MMCMDIV_MUL	(0xff << 16)
> +# define BOSTON_PLAT_MMCMDIV_CLK1DIV	(0xff << 24)
> +
> +#define BOSTON_CLK_COUNT 3
> +
> +struct clk_boston_state {
> +	struct clk *clks[BOSTON_CLK_COUNT];
> +	struct clk_onecell_data onecell_data;
> +};
> +
> +static u32 ext_field(u32 val, u32 mask)
> +{
> +	return (val & mask) >> (ffs(mask) - 1);
> +}
> +
> +static void __init clk_boston_setup(struct device_node *np)
> +{
> +	unsigned long in_freq, cpu_freq, sys_freq;
> +	uint mmcmdiv, mul, cpu_div, sys_div;
> +	struct clk_boston_state *state;
> +	struct regmap *regmap;
> +	struct clk *clk;
> +	int err;
> +
> +	regmap = syscon_node_to_regmap(np->parent);
> +	if (IS_ERR(regmap)) {
> +		pr_err("failed to find regmap\n");
> +		return;
> +	}
> +
> +	err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
> +	if (err) {
> +		pr_err("failed to read mmcm_div register: %d\n", err);
> +		return;
> +	}
> +
> +	in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
> +	mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
> +
> +	sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
> +	sys_freq = mult_frac(in_freq, mul, sys_div);
> +
> +	cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
> +	cpu_freq = mult_frac(in_freq, mul, cpu_div);
> +
> +	state = kzalloc(sizeof(*state), GFP_KERNEL);
> +	if (!state)
> +		return;
> +
> +	clk = clk_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
> +	if (IS_ERR(clk)) {
> +		pr_err("failed to register input clock: %ld\n", PTR_ERR(clk));
> +		return;
> +	}
> +	state->clks[BOSTON_CLK_INPUT] = clk;
> +
> +	clk = clk_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
> +	if (IS_ERR(clk)) {
> +		pr_err("failed to register sys clock: %ld\n", PTR_ERR(clk));
> +		return;
> +	}
> +	state->clks[BOSTON_CLK_SYS] = clk;
> +
> +	clk = clk_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
> +	if (IS_ERR(clk)) {
> +		pr_err("failed to register cpu clock: %ld\n", PTR_ERR(clk));
> +		return;
> +	}
> +	state->clks[BOSTON_CLK_CPU] = clk;
> +
> +	state->onecell_data.clks = state->clks;
> +	state->onecell_data.clk_num = BOSTON_CLK_COUNT;
> +
> +	err = of_clk_add_provider(np, of_clk_src_onecell_get,
> +				  &state->onecell_data);
> +	if (err)
> +		pr_err("failed to add DT provider: %d\n", err);
> +}
> +CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);
> -- 
> 2.13.0

Re: [PATCH v4 2/4] clk: boston: Add a driver for MIPS Boston board clocks

[Stephen Boyd]

On 06/02, Paul Burton wrote:
> diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig
> new file mode 100644
> index 000000000000..c2ea745928e4
> --- /dev/null
> +++ b/drivers/clk/imgtec/Kconfig
> @@ -0,0 +1,10 @@
> +config COMMON_CLK_BOSTON
> +	bool "Clock driver for MIPS Boston boards"
> +	depends on MIPS || COMPILE_TEST
> +	depends on OF

What's the OF build dependency?

> +	select MFD_SYSCON
> +	---help---
> +	  Enable this to support the system & CPU clocks on the MIPS Boston
> +	  development board from Imagination Technologies. These are simple
> +	  fixed rate clocks whose rate is determined by reading a platform
> +	  provided register.
> diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile
> new file mode 100644
> index 000000000000..ac779b8c22f2
> --- /dev/null
> +++ b/drivers/clk/imgtec/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_COMMON_CLK_BOSTON)		+= clk-boston.o
> diff --git a/drivers/clk/imgtec/clk-boston.c b/drivers/clk/imgtec/clk-boston.c
> new file mode 100644
> index 000000000000..98bb0b764d15
> --- /dev/null
> +++ b/drivers/clk/imgtec/clk-boston.c
> @@ -0,0 +1,101 @@
> +/*
> + * Copyright (C) 2016-2017 Imagination Technologies
> + * Author: Paul Burton <paul.burton@imgtec.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation;  either version 2 of the  License, or (at your
> + * option) any later version.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/kernel.h>
> +#include <linux/of.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/mfd/syscon.h>
> +
> +#include <dt-bindings/clock/boston-clock.h>
> +
> +#define BOSTON_PLAT_MMCMDIV		0x30
> +# define BOSTON_PLAT_MMCMDIV_CLK0DIV	(0xff << 0)
> +# define BOSTON_PLAT_MMCMDIV_INPUT	(0xff << 8)
> +# define BOSTON_PLAT_MMCMDIV_MUL	(0xff << 16)
> +# define BOSTON_PLAT_MMCMDIV_CLK1DIV	(0xff << 24)
> +
> +#define BOSTON_CLK_COUNT 3
> +
> +struct clk_boston_state {
> +	struct clk *clks[BOSTON_CLK_COUNT];
> +	struct clk_onecell_data onecell_data;
> +};
> +
> +static u32 ext_field(u32 val, u32 mask)
> +{
> +	return (val & mask) >> (ffs(mask) - 1);
> +}
> +
> +static void __init clk_boston_setup(struct device_node *np)
> +{
> +	unsigned long in_freq, cpu_freq, sys_freq;
> +	uint mmcmdiv, mul, cpu_div, sys_div;
> +	struct clk_boston_state *state;
> +	struct regmap *regmap;
> +	struct clk *clk;
> +	int err;
> +
> +	regmap = syscon_node_to_regmap(np->parent);
> +	if (IS_ERR(regmap)) {
> +		pr_err("failed to find regmap\n");
> +		return;
> +	}
> +
> +	err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
> +	if (err) {
> +		pr_err("failed to read mmcm_div register: %d\n", err);
> +		return;
> +	}
> +
> +	in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
> +	mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
> +
> +	sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
> +	sys_freq = mult_frac(in_freq, mul, sys_div);
> +
> +	cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
> +	cpu_freq = mult_frac(in_freq, mul, cpu_div);
> +
> +	state = kzalloc(sizeof(*state), GFP_KERNEL);
> +	if (!state)
> +		return;
> +
> +	clk = clk_register_fixed_rate(NULL, "input", NULL, 0, in_freq);

Please use the clk_hw_register_*() APIs instead so that this
driver only deals in clk_hw pointers.

> +	if (IS_ERR(clk)) {
> +		pr_err("failed to register input clock: %ld\n", PTR_ERR(clk));
> +		return;
> +	}
> +	state->clks[BOSTON_CLK_INPUT] = clk;
> +
> +	clk = clk_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
> +	if (IS_ERR(clk)) {
> +		pr_err("failed to register sys clock: %ld\n", PTR_ERR(clk));
> +		return;
> +	}
> +	state->clks[BOSTON_CLK_SYS] = clk;
> +
> +	clk = clk_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
> +	if (IS_ERR(clk)) {
> +		pr_err("failed to register cpu clock: %ld\n", PTR_ERR(clk));
> +		return;
> +	}
> +	state->clks[BOSTON_CLK_CPU] = clk;
> +
> +	state->onecell_data.clks = state->clks;
> +	state->onecell_data.clk_num = BOSTON_CLK_COUNT;
> +
> +	err = of_clk_add_provider(np, of_clk_src_onecell_get,
> +				  &state->onecell_data);

Same for here, of_clk_add_hw_provider()

> +	if (err)
> +		pr_err("failed to add DT provider: %d\n", err);
> +}
> +CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);

Can this be a platform driver? The syscon mfd can populate child
nodes and this could be a driver that binds to the clock child
node.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v4 2/4] clk: boston: Add a driver for MIPS Boston board clocks

[Paul Burton]

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Hi Stephen,

On Wednesday, 14 June 2017 09:01:06 PDT Stephen Boyd wrote:
> On 06/02, Paul Burton wrote:
> > diff --git a/drivers/clk/imgtec/Kconfig b/drivers/clk/imgtec/Kconfig
> > new file mode 100644
> > index 000000000000..c2ea745928e4
> > --- /dev/null
> > +++ b/drivers/clk/imgtec/Kconfig
> > @@ -0,0 +1,10 @@
> > +config COMMON_CLK_BOSTON
> > +	bool "Clock driver for MIPS Boston boards"
> > +	depends on MIPS || COMPILE_TEST
> > +	depends on OF
> 
> What's the OF build dependency?

Dropped for v5, though the driver won't actually be used on systems without 
CONFIG_OF.

> > +	select MFD_SYSCON
> > +	---help---
> > +	  Enable this to support the system & CPU clocks on the MIPS Boston
> > +	  development board from Imagination Technologies. These are simple
> > +	  fixed rate clocks whose rate is determined by reading a platform
> > +	  provided register.
> > diff --git a/drivers/clk/imgtec/Makefile b/drivers/clk/imgtec/Makefile
> > new file mode 100644
> > index 000000000000..ac779b8c22f2
> > --- /dev/null
> > +++ b/drivers/clk/imgtec/Makefile
> > @@ -0,0 +1 @@
> > +obj-$(CONFIG_COMMON_CLK_BOSTON)		+= clk-boston.o
> > diff --git a/drivers/clk/imgtec/clk-boston.c
> > b/drivers/clk/imgtec/clk-boston.c new file mode 100644
> > index 000000000000..98bb0b764d15
> > --- /dev/null
> > +++ b/drivers/clk/imgtec/clk-boston.c
> > @@ -0,0 +1,101 @@
> > +/*
> > + * Copyright (C) 2016-2017 Imagination Technologies
> > + * Author: Paul Burton <paul.burton@imgtec.com>
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > it
> > + * under the terms of the GNU General Public License as published by the
> > + * Free Software Foundation;  either version 2 of the  License, or (at
> > your + * option) any later version.
> > + */
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/kernel.h>
> > +#include <linux/of.h>
> > +#include <linux/regmap.h>
> > +#include <linux/slab.h>
> > +#include <linux/mfd/syscon.h>
> > +
> > +#include <dt-bindings/clock/boston-clock.h>
> > +
> > +#define BOSTON_PLAT_MMCMDIV		0x30
> > +# define BOSTON_PLAT_MMCMDIV_CLK0DIV	(0xff << 0)
> > +# define BOSTON_PLAT_MMCMDIV_INPUT	(0xff << 8)
> > +# define BOSTON_PLAT_MMCMDIV_MUL	(0xff << 16)
> > +# define BOSTON_PLAT_MMCMDIV_CLK1DIV	(0xff << 24)
> > +
> > +#define BOSTON_CLK_COUNT 3
> > +
> > +struct clk_boston_state {
> > +	struct clk *clks[BOSTON_CLK_COUNT];
> > +	struct clk_onecell_data onecell_data;
> > +};
> > +
> > +static u32 ext_field(u32 val, u32 mask)
> > +{
> > +	return (val & mask) >> (ffs(mask) - 1);
> > +}
> > +
> > +static void __init clk_boston_setup(struct device_node *np)
> > +{
> > +	unsigned long in_freq, cpu_freq, sys_freq;
> > +	uint mmcmdiv, mul, cpu_div, sys_div;
> > +	struct clk_boston_state *state;
> > +	struct regmap *regmap;
> > +	struct clk *clk;
> > +	int err;
> > +
> > +	regmap = syscon_node_to_regmap(np->parent);
> > +	if (IS_ERR(regmap)) {
> > +		pr_err("failed to find regmap\n");
> > +		return;
> > +	}
> > +
> > +	err = regmap_read(regmap, BOSTON_PLAT_MMCMDIV, &mmcmdiv);
> > +	if (err) {
> > +		pr_err("failed to read mmcm_div register: %d\n", err);
> > +		return;
> > +	}
> > +
> > +	in_freq = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_INPUT) * 1000000;
> > +	mul = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_MUL);
> > +
> > +	sys_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK0DIV);
> > +	sys_freq = mult_frac(in_freq, mul, sys_div);
> > +
> > +	cpu_div = ext_field(mmcmdiv, BOSTON_PLAT_MMCMDIV_CLK1DIV);
> > +	cpu_freq = mult_frac(in_freq, mul, cpu_div);
> > +
> > +	state = kzalloc(sizeof(*state), GFP_KERNEL);
> > +	if (!state)
> > +		return;
> > +
> > +	clk = clk_register_fixed_rate(NULL, "input", NULL, 0, in_freq);
> 
> Please use the clk_hw_register_*() APIs instead so that this
> driver only deals in clk_hw pointers.

OK, done in v5.

> > +	if (IS_ERR(clk)) {
> > +		pr_err("failed to register input clock: %ld\n", PTR_ERR(clk));
> > +		return;
> > +	}
> > +	state->clks[BOSTON_CLK_INPUT] = clk;
> > +
> > +	clk = clk_register_fixed_rate(NULL, "sys", "input", 0, sys_freq);
> > +	if (IS_ERR(clk)) {
> > +		pr_err("failed to register sys clock: %ld\n", PTR_ERR(clk));
> > +		return;
> > +	}
> > +	state->clks[BOSTON_CLK_SYS] = clk;
> > +
> > +	clk = clk_register_fixed_rate(NULL, "cpu", "input", 0, cpu_freq);
> > +	if (IS_ERR(clk)) {
> > +		pr_err("failed to register cpu clock: %ld\n", PTR_ERR(clk));
> > +		return;
> > +	}
> > +	state->clks[BOSTON_CLK_CPU] = clk;
> > +
> > +	state->onecell_data.clks = state->clks;
> > +	state->onecell_data.clk_num = BOSTON_CLK_COUNT;
> > +
> > +	err = of_clk_add_provider(np, of_clk_src_onecell_get,
> > +				  &state->onecell_data);
> 
> Same for here, of_clk_add_hw_provider()

Done in v5.

> > +	if (err)
> > +		pr_err("failed to add DT provider: %d\n", err);
> > +}
> > +CLK_OF_DECLARE(clk_boston, "img,boston-clock", clk_boston_setup);
> 
> Can this be a platform driver? The syscon mfd can populate child
> nodes and this could be a driver that binds to the clock child
> node.

Sadly no, it can't. This driver provides the CPU frequency which we need early 
on. I've added a comment to that effect in v5.

Thanks,
    Paul

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