diff mbox series

[v2,4/7] clk: mstar: MStar/SigmaStar MPLL driver

Message ID 20210211052206.2955988-5-daniel@0x0f.com (mailing list archive)
State Accepted, archived
Headers show
Series ARM: mstar: Basic MPLL support | expand

Commit Message

Daniel Palmer Feb. 11, 2021, 5:22 a.m. UTC 
This adds a basic driver for the MPLL block found in MStar/SigmaStar
ARMv7 SoCs.

Currently this driver is only good for calculating the rates of it's
outputs and the actual configuration must be done before the kernel
boots. Usually this is done even before u-boot starts.

This driver targets the MPLL block found in the MSC313/MSC313E but
there is no documentation this chip so the register descriptions for
the another MStar chip the MST786 were used as they seem to match.

Signed-off-by: Daniel Palmer <daniel@0x0f.com>
---
 MAINTAINERS                         |   1 +
 drivers/clk/Kconfig                 |   1 +
 drivers/clk/Makefile                |   1 +
 drivers/clk/mstar/Kconfig           |   5 +
 drivers/clk/mstar/Makefile          |   6 ++
 drivers/clk/mstar/clk-msc313-mpll.c | 155 ++++++++++++++++++++++++++++
 6 files changed, 169 insertions(+)
 create mode 100644 drivers/clk/mstar/Kconfig
 create mode 100644 drivers/clk/mstar/Makefile
 create mode 100644 drivers/clk/mstar/clk-msc313-mpll.c

Comments

Stephen Boyd Feb. 14, 2021, 8:32 p.m. UTC | #1 
Quoting Daniel Palmer (2021-02-10 21:22:03)
> This adds a basic driver for the MPLL block found in MStar/SigmaStar
> ARMv7 SoCs.
> 
> Currently this driver is only good for calculating the rates of it's
> outputs and the actual configuration must be done before the kernel
> boots. Usually this is done even before u-boot starts.
> 
> This driver targets the MPLL block found in the MSC313/MSC313E but
> there is no documentation this chip so the register descriptions for
> the another MStar chip the MST786 were used as they seem to match.
> 
> Signed-off-by: Daniel Palmer <daniel@0x0f.com>
> ---

Applied to clk-next
Stephen Boyd Feb. 14, 2021, 8:48 p.m. UTC | #2 
Quoting Daniel Palmer (2021-02-10 21:22:03)
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 85856cff506c..a29c15444d0e 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -379,6 +379,7 @@ source "drivers/clk/ingenic/Kconfig"
>  source "drivers/clk/keystone/Kconfig"
>  source "drivers/clk/mediatek/Kconfig"
>  source "drivers/clk/meson/Kconfig"
> +source "drivers/clk/mstar/Kconfig"
>  source "drivers/clk/mvebu/Kconfig"
>  source "drivers/clk/qcom/Kconfig"
>  source "drivers/clk/renesas/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index dbdc590e7de3..7fed7e5944cd 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_MACH_PIC32)              += microchip/
>  ifeq ($(CONFIG_COMMON_CLK), y)
>  obj-$(CONFIG_ARCH_MMP)                 += mmp/
>  endif
> +obj-$(CONFIG_ARCH_MSTARV7)             += mstar/
>  obj-y                                  += mvebu/
>  obj-$(CONFIG_ARCH_MXS)                 += mxs/
>  obj-$(CONFIG_COMMON_CLK_NXP)           += nxp/
> diff --git a/drivers/clk/mstar/Kconfig b/drivers/clk/mstar/Kconfig
> new file mode 100644
> index 000000000000..23765edde3af
> --- /dev/null
> +++ b/drivers/clk/mstar/Kconfig
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config MSTAR_MSC313_MPLL
> +       bool
> +       select REGMAP
> +       select REGMAP_MMIO

BTW, it would be nice to expose this driver to compile testing instead
of putting it behind ARCH_MSTARTV7. Can we have this patch?

---8<---
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 7fed7e5944cd..e5e23a44fbe9 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -95,7 +95,7 @@ obj-$(CONFIG_MACH_PIC32)		+= microchip/
 ifeq ($(CONFIG_COMMON_CLK), y)
 obj-$(CONFIG_ARCH_MMP)			+= mmp/
 endif
-obj-$(CONFIG_ARCH_MSTARV7)		+= mstar/
+obj-y					+= mstar/
 obj-y					+= mvebu/
 obj-$(CONFIG_ARCH_MXS)			+= mxs/
 obj-$(CONFIG_COMMON_CLK_NXP)		+= nxp/
diff --git a/drivers/clk/mstar/Kconfig b/drivers/clk/mstar/Kconfig
index 23765edde3af..adac76f60f3e 100644
--- a/drivers/clk/mstar/Kconfig
+++ b/drivers/clk/mstar/Kconfig
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config MSTAR_MSC313_MPLL
-	bool
-	select REGMAP
+	bool "MStar MPLL driver"
+	depends on ARCH_MSTARV7 || COMPILE_TEST
+	default ARCH_MSTARV7
 	select REGMAP_MMIO
Daniel Palmer Feb. 15, 2021, 11:04 a.m. UTC | #3 
Hi Stephen,

On Mon, 15 Feb 2021 at 05:48, Stephen Boyd <sboyd@kernel.org> wrote:
> BTW, it would be nice to expose this driver to compile testing instead
> of putting it behind ARCH_MSTARTV7. Can we have this patch?

I like that idea. I'll send a patch.

Thanks,

Daniel
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index d004436c8860..d8414dbfebec 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2149,6 +2149,7 @@  F:	Documentation/devicetree/bindings/clock/mstar,msc313-mpll.yaml
 F:	Documentation/devicetree/bindings/gpio/mstar,msc313-gpio.yaml
 F:	arch/arm/boot/dts/mstar-*
 F:	arch/arm/mach-mstar/
+F:	drivers/clk/mstar/
 F:	drivers/gpio/gpio-msc313.c
 F:	include/dt-bindings/clock/mstar-*
 F:	include/dt-bindings/gpio/msc313-gpio.h
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 85856cff506c..a29c15444d0e 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -379,6 +379,7 @@  source "drivers/clk/ingenic/Kconfig"
 source "drivers/clk/keystone/Kconfig"
 source "drivers/clk/mediatek/Kconfig"
 source "drivers/clk/meson/Kconfig"
+source "drivers/clk/mstar/Kconfig"
 source "drivers/clk/mvebu/Kconfig"
 source "drivers/clk/qcom/Kconfig"
 source "drivers/clk/renesas/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index dbdc590e7de3..7fed7e5944cd 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -95,6 +95,7 @@  obj-$(CONFIG_MACH_PIC32)		+= microchip/
 ifeq ($(CONFIG_COMMON_CLK), y)
 obj-$(CONFIG_ARCH_MMP)			+= mmp/
 endif
+obj-$(CONFIG_ARCH_MSTARV7)		+= mstar/
 obj-y					+= mvebu/
 obj-$(CONFIG_ARCH_MXS)			+= mxs/
 obj-$(CONFIG_COMMON_CLK_NXP)		+= nxp/
diff --git a/drivers/clk/mstar/Kconfig b/drivers/clk/mstar/Kconfig
new file mode 100644
index 000000000000..23765edde3af
--- /dev/null
+++ b/drivers/clk/mstar/Kconfig
@@ -0,0 +1,5 @@ 
+# SPDX-License-Identifier: GPL-2.0-only
+config MSTAR_MSC313_MPLL
+	bool
+	select REGMAP
+	select REGMAP_MMIO
diff --git a/drivers/clk/mstar/Makefile b/drivers/clk/mstar/Makefile
new file mode 100644
index 000000000000..f8dcd25ede1d
--- /dev/null
+++ b/drivers/clk/mstar/Makefile
@@ -0,0 +1,6 @@ 
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for mstar specific clk
+#
+
+obj-$(CONFIG_MSTAR_MSC313_MPLL) += clk-msc313-mpll.o
diff --git a/drivers/clk/mstar/clk-msc313-mpll.c b/drivers/clk/mstar/clk-msc313-mpll.c
new file mode 100644
index 000000000000..09f578108eef
--- /dev/null
+++ b/drivers/clk/mstar/clk-msc313-mpll.c
@@ -0,0 +1,155 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MStar MSC313 MPLL driver
+ *
+ * Copyright (C) 2020 Daniel Palmer <daniel@thingy.jp>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+
+#define REG_CONFIG1	0x8
+#define REG_CONFIG2	0xc
+
+static const struct regmap_config msc313_mpll_regmap_config = {
+	.reg_bits = 16,
+	.val_bits = 16,
+	.reg_stride = 4,
+};
+
+static const struct reg_field config1_loop_div_first = REG_FIELD(REG_CONFIG1, 8, 9);
+static const struct reg_field config1_input_div_first = REG_FIELD(REG_CONFIG1, 4, 5);
+static const struct reg_field config2_output_div_first = REG_FIELD(REG_CONFIG2, 12, 13);
+static const struct reg_field config2_loop_div_second = REG_FIELD(REG_CONFIG2, 0, 7);
+
+static const unsigned int output_dividers[] = {
+	2, 3, 4, 5, 6, 7, 10
+};
+
+#define NUMOUTPUTS (ARRAY_SIZE(output_dividers) + 1)
+
+struct msc313_mpll {
+	struct clk_hw clk_hw;
+	struct regmap_field *input_div;
+	struct regmap_field *loop_div_first;
+	struct regmap_field *loop_div_second;
+	struct regmap_field *output_div;
+	struct clk_hw_onecell_data *clk_data;
+};
+
+#define to_mpll(_hw) container_of(_hw, struct msc313_mpll, clk_hw)
+
+static unsigned long msc313_mpll_recalc_rate(struct clk_hw *hw,
+		unsigned long parent_rate)
+{
+	struct msc313_mpll *mpll = to_mpll(hw);
+	unsigned int input_div, output_div, loop_first, loop_second;
+	unsigned long output_rate;
+
+	regmap_field_read(mpll->input_div, &input_div);
+	regmap_field_read(mpll->output_div, &output_div);
+	regmap_field_read(mpll->loop_div_first, &loop_first);
+	regmap_field_read(mpll->loop_div_second, &loop_second);
+
+	output_rate = parent_rate / (1 << input_div);
+	output_rate *= (1 << loop_first) * max(loop_second, 1U);
+	output_rate /= max(output_div, 1U);
+
+	return output_rate;
+}
+
+static const struct clk_ops msc313_mpll_ops = {
+	.recalc_rate = msc313_mpll_recalc_rate,
+};
+
+static const struct clk_parent_data mpll_parent = {
+	.index	= 0,
+};
+
+static int msc313_mpll_probe(struct platform_device *pdev)
+{
+	void __iomem *base;
+	struct msc313_mpll *mpll;
+	struct clk_init_data clk_init = { };
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap;
+	char *outputname;
+	struct clk_hw *divhw;
+	int ret, i;
+
+	mpll = devm_kzalloc(dev, sizeof(*mpll), GFP_KERNEL);
+	if (!mpll)
+		return -ENOMEM;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &msc313_mpll_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	mpll->input_div = devm_regmap_field_alloc(dev, regmap, config1_input_div_first);
+	if (IS_ERR(mpll->input_div))
+		return PTR_ERR(mpll->input_div);
+	mpll->output_div = devm_regmap_field_alloc(dev, regmap, config2_output_div_first);
+	if (IS_ERR(mpll->output_div))
+		return PTR_ERR(mpll->output_div);
+	mpll->loop_div_first = devm_regmap_field_alloc(dev, regmap, config1_loop_div_first);
+	if (IS_ERR(mpll->loop_div_first))
+		return PTR_ERR(mpll->loop_div_first);
+	mpll->loop_div_second = devm_regmap_field_alloc(dev, regmap, config2_loop_div_second);
+	if (IS_ERR(mpll->loop_div_second))
+		return PTR_ERR(mpll->loop_div_second);
+
+	mpll->clk_data = devm_kzalloc(dev, struct_size(mpll->clk_data, hws,
+			ARRAY_SIZE(output_dividers)), GFP_KERNEL);
+	if (!mpll->clk_data)
+		return -ENOMEM;
+
+	clk_init.name = dev_name(dev);
+	clk_init.ops = &msc313_mpll_ops;
+	clk_init.parent_data = &mpll_parent;
+	clk_init.num_parents = 1;
+	mpll->clk_hw.init = &clk_init;
+
+	ret = devm_clk_hw_register(dev, &mpll->clk_hw);
+	if (ret)
+		return ret;
+
+	mpll->clk_data->num = NUMOUTPUTS;
+	mpll->clk_data->hws[0] = &mpll->clk_hw;
+
+	for (i = 0; i < ARRAY_SIZE(output_dividers); i++) {
+		outputname = devm_kasprintf(dev, GFP_KERNEL, "%s_div_%d",
+				clk_init.name, output_dividers[i]);
+		if (!outputname)
+			return -ENOMEM;
+		divhw = devm_clk_hw_register_fixed_factor(dev, outputname,
+				clk_init.name, 0, 1, output_dividers[i]);
+		if (IS_ERR(divhw))
+			return PTR_ERR(divhw);
+		mpll->clk_data->hws[i + 1] = divhw;
+	}
+
+	platform_set_drvdata(pdev, mpll);
+
+	return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
+			mpll->clk_data);
+}
+
+static const struct of_device_id msc313_mpll_of_match[] = {
+	{ .compatible = "mstar,msc313-mpll", },
+	{}
+};
+
+static struct platform_driver msc313_mpll_driver = {
+	.driver = {
+		.name = "mstar-msc313-mpll",
+		.of_match_table = msc313_mpll_of_match,
+	},
+	.probe = msc313_mpll_probe,
+};
+builtin_platform_driver(msc313_mpll_driver);