Thread (16 messages) 16 messages, 4 authors, 2025-08-25
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[PATCH 3/3] clk: samsung: add Exynos ACPM clock driver

From: Tudor Ambarus <tudor.ambarus@linaro.org>
Date: 2025-08-19 11:45:57
Also in: linux-clk, linux-devicetree, linux-samsung-soc, lkml
Subsystem: common clk framework, samsung exynos acpm mailbox protocol, samsung soc clock drivers, the rest · Maintainers: Michael Turquette, Stephen Boyd, Tudor Ambarus, Krzysztof Kozlowski, Sylwester Nawrocki, Chanwoo Choi, Peter Griffin, Linus Torvalds

Add the Exynos ACPM clock driver. It provides support for clocks that
are controlled by firmware that implements the ACPM interface.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
---
 drivers/clk/samsung/Kconfig    |  10 +++
 drivers/clk/samsung/Makefile   |   1 +
 drivers/clk/samsung/clk-acpm.c | 192 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 203 insertions(+)
diff --git a/drivers/clk/samsung/Kconfig b/drivers/clk/samsung/Kconfig
index 76a494e95027af26272e30876a87ac293bd56dfa..fe05212d7dd882adde9cd5c656cd0d58d501c42f 100644
--- a/drivers/clk/samsung/Kconfig
+++ b/drivers/clk/samsung/Kconfig
@@ -95,6 +95,16 @@ config EXYNOS_CLKOUT
 	  status of the certains clocks from SoC, but it could also be tied to
 	  other devices as an input clock.
 
+config EXYNOS_ACPM_CLK
+	tristate "Clock driver controlled via ACPM interface"
+	depends on EXYNOS_ACPM_PROTOCOL || COMPILE_TEST
+	help
+	  This driver provides support for clocks that are controlled by
+	  firmware that implements the ACPM interface.
+
+	  This driver uses the ACPM interface to interact with the firmware
+	  providing all the clock controlls.
+
 config TESLA_FSD_COMMON_CLK
 	bool "Tesla FSD clock controller support" if COMPILE_TEST
 	depends on COMMON_CLK_SAMSUNG
diff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile
index b77fe288e4bb484c68d1ff497acc0b83d132ea03..04b63436b12f6f5169575d74f54b105e97bbb052 100644
--- a/drivers/clk/samsung/Makefile
+++ b/drivers/clk/samsung/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynos990.o
 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynosautov9.o
 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-exynosautov920.o
 obj-$(CONFIG_EXYNOS_ARM64_COMMON_CLK)	+= clk-gs101.o
+obj-$(CONFIG_EXYNOS_ACPM_CLK)		+= clk-acpm.o
 obj-$(CONFIG_S3C64XX_COMMON_CLK)	+= clk-s3c64xx.o
 obj-$(CONFIG_S5PV210_COMMON_CLK)	+= clk-s5pv210.o clk-s5pv210-audss.o
 obj-$(CONFIG_TESLA_FSD_COMMON_CLK)	+= clk-fsd.o
diff --git a/drivers/clk/samsung/clk-acpm.c b/drivers/clk/samsung/clk-acpm.c
new file mode 100644
index 0000000000000000000000000000000000000000..e3e648331ad54072876f52a63b11fe259a0b9be2
--- /dev/null
+++ b/drivers/clk/samsung/clk-acpm.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Samsung Exynos ACPM protocol based clock driver.
+ *
+ * Copyright 2025 Linaro Ltd.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/firmware/samsung/exynos-acpm-protocol.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#include <dt-bindings/clock/google,gs101.h>
+
+struct acpm_clk {
+	u32 id;
+	struct clk_hw hw;
+	unsigned int acpm_chan_id;
+	const struct acpm_handle *handle;
+};
+
+#define to_acpm_clk(clk) container_of(clk, struct acpm_clk, hw)
+
+struct acpm_clk_variant {
+	unsigned int id;
+	const char *name;
+};
+
+struct acpm_clk_match_data {
+	const struct acpm_clk_variant *clks;
+	unsigned int nr_clks;
+	unsigned int acpm_chan_id;
+};
+
+static unsigned long acpm_clk_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct acpm_clk *clk = to_acpm_clk(hw);
+
+	return clk->handle->ops.dvfs_ops.get_rate(clk->handle,
+					clk->acpm_chan_id, clk->id, 0);
+}
+
+static long acpm_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long *parent_rate)
+{
+	/*
+	 * We can't figure out what rate it will be, so just return the
+	 * rate back to the caller. acpm_clk_recalc_rate() will be called
+	 * after the rate is set and we'll know what rate the clock is
+	 * running at then.
+	 */
+	return rate;
+}
+
+static int acpm_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+			     unsigned long parent_rate)
+{
+	struct acpm_clk *clk = to_acpm_clk(hw);
+
+	return clk->handle->ops.dvfs_ops.set_rate(clk->handle,
+					clk->acpm_chan_id, clk->id, rate);
+}
+
+static const struct clk_ops acpm_clk_ops = {
+	.recalc_rate = acpm_clk_recalc_rate,
+	.round_rate = acpm_clk_round_rate,
+	.set_rate = acpm_clk_set_rate,
+};
+
+static int __init acpm_clk_ops_init(struct device *dev, struct acpm_clk *aclk,
+				    const char *name)
+{
+	struct clk_init_data init = {};
+
+	init.name = name;
+	init.ops = &acpm_clk_ops;
+	aclk->hw.init = &init;
+
+	return devm_clk_hw_register(dev, &aclk->hw);
+}
+
+static int __init acpm_clk_probe(struct platform_device *pdev)
+{
+	const struct acpm_clk_match_data *match_data;
+	const struct acpm_handle *acpm_handle;
+	struct clk_hw_onecell_data *clk_data;
+	struct clk_hw **hws;
+	struct device *dev = &pdev->dev;
+	struct acpm_clk *aclks;
+	unsigned int acpm_chan_id;
+	int i, err, count;
+
+	acpm_handle = devm_acpm_get_by_node(dev, dev->parent->of_node);
+	if (IS_ERR(acpm_handle))
+		return dev_err_probe(dev, PTR_ERR(acpm_handle),
+				     "Failed to get acpm handle.\n");
+
+	match_data = of_device_get_match_data(dev);
+	if (!match_data)
+		return dev_err_probe(dev, -EINVAL,
+				     "Failed to get match data.\n");
+
+	count = match_data->nr_clks;
+	acpm_chan_id = match_data->acpm_chan_id;
+
+	clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, count),
+				GFP_KERNEL);
+	if (!clk_data)
+		return -ENOMEM;
+
+	clk_data->num = count;
+	hws = clk_data->hws;
+
+	aclks = devm_kcalloc(dev, count, sizeof(*aclks), GFP_KERNEL);
+	if (!aclks)
+		return -ENOMEM;
+
+	for (i = 0; i < count; i++) {
+		const struct acpm_clk_variant *variant = &match_data->clks[i];
+		struct acpm_clk *aclk = &aclks[i];
+
+		hws[i] = &aclk->hw;
+
+		aclk->id = variant->id;
+		aclk->handle = acpm_handle;
+		aclk->acpm_chan_id = acpm_chan_id;
+
+		err = acpm_clk_ops_init(dev, aclk, variant->name);
+		if (err)
+			return dev_err_probe(dev, err,
+					     "Failed to register clock.\n");
+	}
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					   clk_data);
+}
+
+#define ACPM_CLK(_id, cname)					\
+	{							\
+		.id		= _id,				\
+		.name		= cname,			\
+	}
+
+static const struct acpm_clk_variant gs101_acpm_clks[] __initconst = {
+	ACPM_CLK(CLK_ACPM_DVFS_MIF, "mif"),
+	ACPM_CLK(CLK_ACPM_DVFS_INT, "int"),
+	ACPM_CLK(CLK_ACPM_DVFS_CPUCL0, "cpucl0"),
+	ACPM_CLK(CLK_ACPM_DVFS_CPUCL1, "cpucl1"),
+	ACPM_CLK(CLK_ACPM_DVFS_CPUCL2, "cpucl2"),
+	ACPM_CLK(CLK_ACPM_DVFS_G3D, "g3d"),
+	ACPM_CLK(CLK_ACPM_DVFS_G3DL2, "g3dl2"),
+	ACPM_CLK(CLK_ACPM_DVFS_TPU, "tpu"),
+	ACPM_CLK(CLK_ACPM_DVFS_INTCAM, "intcam"),
+	ACPM_CLK(CLK_ACPM_DVFS_TNR, "tnr"),
+	ACPM_CLK(CLK_ACPM_DVFS_CAM, "cam"),
+	ACPM_CLK(CLK_ACPM_DVFS_MFC, "mfc"),
+	ACPM_CLK(CLK_ACPM_DVFS_DISP, "disp"),
+	ACPM_CLK(CLK_ACPM_DVFS_BO, "b0"),
+};
+
+static const struct acpm_clk_match_data acpm_clk_gs101 __initconst = {
+	.clks = gs101_acpm_clks,
+	.nr_clks = ARRAY_SIZE(gs101_acpm_clks),
+	.acpm_chan_id = 0,
+};
+
+static const struct of_device_id acpm_clk_ids[] __initconst = {
+	{
+		.compatible = "google,gs101-acpm-dvfs-clocks",
+		.data =  &acpm_clk_gs101,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, acpm_clk_ids);
+
+static struct platform_driver acpm_clk_driver __refdata = {
+	.driver	= {
+		.name = "acpm-clocks",
+		.of_match_table = acpm_clk_ids,
+	},
+	.probe = acpm_clk_probe,
+};
+module_platform_driver(acpm_clk_driver);
+
+MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@linaro.org>");
+MODULE_DESCRIPTION("Samsung Exynos ACPM clock driver");
+MODULE_LICENSE("GPL");
-- 
2.51.0.rc1.167.g924127e9c0-goog

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