clk: qcom: clk-rpmh: Add QCOM RPMh clock driver

Add the RPMh clock driver to control the RPMh managed clock resources on
some of the Qualcomm Technologies, Inc. SoCs.

Signed-off-by: Taniya Das <tdas@codeaurora.org>
[sboyd@kernel.org: Clean up whitespace, indentation, remove
cmd_db_ready check]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/qcom/Kconfig

@@ -59,6 +59,15 @@ config QCOM_CLK_SMD_RPM
 	  Say Y if you want to support the clocks exposed by the RPM on
 	  platforms such as apq8016, apq8084, msm8974 etc.
 
+config QCOM_CLK_RPMH
+	tristate "RPMh Clock Driver"
+	depends on COMMON_CLK_QCOM && QCOM_RPMH
+	help
+	 RPMh manages shared resources on some Qualcomm Technologies, Inc.
+	 SoCs. It accepts requests from other hardware subsystems via RSC.
+	 Say Y if you want to support the clocks exposed by RPMh on
+	 platforms such as SDM845.
+
 config APQ_GCC_8084
 	tristate "APQ8084 Global Clock Controller"
 	select QCOM_GDSC

drivers/clk/qcom/Makefile

@@ -37,6 +37,7 @@ obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o
 obj-$(CONFIG_QCOM_A53PLL) += a53-pll.o
 obj-$(CONFIG_QCOM_CLK_APCS_MSM8916) += apcs-msm8916.o
 obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o
+obj-$(CONFIG_QCOM_CLK_RPMH) += clk-rpmh.o
 obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o
 obj-$(CONFIG_SDM_GCC_845) += gcc-sdm845.o
 obj-$(CONFIG_SDM_VIDEOCC_845) += videocc-sdm845.o

drivers/clk/qcom/clk-rpmh.c

@@ -0,0 +1,329 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <soc/qcom/cmd-db.h>
+#include <soc/qcom/rpmh.h>
+
+#include <dt-bindings/clock/qcom,rpmh.h>
+
+#define CLK_RPMH_ARC_EN_OFFSET		0
+#define CLK_RPMH_VRM_EN_OFFSET		4
+
+/**
+ * struct clk_rpmh - individual rpmh clock data structure
+ * @hw:			handle between common and hardware-specific interfaces
+ * @res_name:		resource name for the rpmh clock
+ * @div:		clock divider to compute the clock rate
+ * @res_addr:		base address of the rpmh resource within the RPMh
+ * @res_on_val:		rpmh clock enable value
+ * @state:		rpmh clock requested state
+ * @aggr_state:		rpmh clock aggregated state
+ * @last_sent_aggr_state: rpmh clock last aggr state sent to RPMh
+ * @valid_state_mask:	mask to determine the state of the rpmh clock
+ * @dev:		device to which it is attached
+ * @peer:		pointer to the clock rpmh sibling
+ */
+struct clk_rpmh {
+	struct clk_hw hw;
+	const char *res_name;
+	u8 div;
+	u32 res_addr;
+	u32 res_on_val;
+	u32 state;
+	u32 aggr_state;
+	u32 last_sent_aggr_state;
+	u32 valid_state_mask;
+	struct device *dev;
+	struct clk_rpmh *peer;
+};
+
+struct clk_rpmh_desc {
+	struct clk_hw **clks;
+	size_t num_clks;
+};
+
+static DEFINE_MUTEX(rpmh_clk_lock);
+
+#define __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,	\
+			  _res_en_offset, _res_on, _div)		\
+	static struct clk_rpmh _platform##_##_name_active;		\
+	static struct clk_rpmh _platform##_##_name = {			\
+		.res_name = _res_name,					\
+		.res_addr = _res_en_offset,				\
+		.res_on_val = _res_on,					\
+		.div = _div,						\
+		.peer = &_platform##_##_name_active,			\
+		.valid_state_mask = (BIT(RPMH_WAKE_ONLY_STATE) |	\
+				      BIT(RPMH_ACTIVE_ONLY_STATE) |	\
+				      BIT(RPMH_SLEEP_STATE)),		\
+		.hw.init = &(struct clk_init_data){			\
+			.ops = &clk_rpmh_ops,				\
+			.name = #_name,					\
+			.parent_names = (const char *[]){ "xo_board" },	\
+			.num_parents = 1,				\
+		},							\
+	};								\
+	static struct clk_rpmh _platform##_##_name_active = {		\
+		.res_name = _res_name,					\
+		.res_addr = _res_en_offset,				\
+		.res_on_val = _res_on,					\
+		.div = _div,						\
+		.peer = &_platform##_##_name,				\
+		.valid_state_mask = (BIT(RPMH_WAKE_ONLY_STATE) |	\
+					BIT(RPMH_ACTIVE_ONLY_STATE)),	\
+		.hw.init = &(struct clk_init_data){			\
+			.ops = &clk_rpmh_ops,				\
+			.name = #_name_active,				\
+			.parent_names = (const char *[]){ "xo_board" },	\
+			.num_parents = 1,				\
+		},							\
+	}
+
+#define DEFINE_CLK_RPMH_ARC(_platform, _name, _name_active, _res_name,	\
+			    _res_on, _div)				\
+	__DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,	\
+			  CLK_RPMH_ARC_EN_OFFSET, _res_on, _div)
+
+#define DEFINE_CLK_RPMH_VRM(_platform, _name, _name_active, _res_name,	\
+				_div)					\
+	__DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,	\
+			  CLK_RPMH_VRM_EN_OFFSET, 1, _div)
+
+static inline struct clk_rpmh *to_clk_rpmh(struct clk_hw *_hw)
+{
+	return container_of(_hw, struct clk_rpmh, hw);
+}
+
+static inline bool has_state_changed(struct clk_rpmh *c, u32 state)
+{
+	return (c->last_sent_aggr_state & BIT(state))
+		!= (c->aggr_state & BIT(state));
+}
+
+static int clk_rpmh_send_aggregate_command(struct clk_rpmh *c)
+{
+	struct tcs_cmd cmd = { 0 };
+	u32 cmd_state, on_val;
+	enum rpmh_state state = RPMH_SLEEP_STATE;
+	int ret;
+
+	cmd.addr = c->res_addr;
+	cmd_state = c->aggr_state;
+	on_val = c->res_on_val;
+
+	for (; state <= RPMH_ACTIVE_ONLY_STATE; state++) {
+		if (has_state_changed(c, state)) {
+			if (cmd_state & BIT(state))
+				cmd.data = on_val;
+
+			ret = rpmh_write_async(c->dev, state, &cmd, 1);
+			if (ret) {
+				dev_err(c->dev, "set %s state of %s failed: (%d)\n",
+					!state ? "sleep" :
+					state == RPMH_WAKE_ONLY_STATE	?
+					"wake" : "active", c->res_name, ret);
+				return ret;
+			}
+		}
+	}
+
+	c->last_sent_aggr_state = c->aggr_state;
+	c->peer->last_sent_aggr_state =  c->last_sent_aggr_state;
+
+	return 0;
+}
+
+/*
+ * Update state and aggregate state values based on enable value.
+ */
+static int clk_rpmh_aggregate_state_send_command(struct clk_rpmh *c,
+						bool enable)
+{
+	int ret;
+
+	/* Nothing required to be done if already off or on */
+	if (enable == c->state)
+		return 0;
+
+	c->state = enable ? c->valid_state_mask : 0;
+	c->aggr_state = c->state | c->peer->state;
+	c->peer->aggr_state = c->aggr_state;
+
+	ret = clk_rpmh_send_aggregate_command(c);
+	if (!ret)
+		return 0;
+
+	if (ret && enable)
+		c->state = 0;
+	else if (ret)
+		c->state = c->valid_state_mask;
+
+	WARN(1, "clk: %s failed to %s\n", c->res_name,
+	     enable ? "enable" : "disable");
+	return ret;
+}
+
+static int clk_rpmh_prepare(struct clk_hw *hw)
+{
+	struct clk_rpmh *c = to_clk_rpmh(hw);
+	int ret = 0;
+
+	mutex_lock(&rpmh_clk_lock);
+	ret = clk_rpmh_aggregate_state_send_command(c, true);
+	mutex_unlock(&rpmh_clk_lock);
+
+	return ret;
+};
+
+static void clk_rpmh_unprepare(struct clk_hw *hw)
+{
+	struct clk_rpmh *c = to_clk_rpmh(hw);
+
+	mutex_lock(&rpmh_clk_lock);
+	clk_rpmh_aggregate_state_send_command(c, false);
+	mutex_unlock(&rpmh_clk_lock);
+};
+
+static unsigned long clk_rpmh_recalc_rate(struct clk_hw *hw,
+					unsigned long prate)
+{
+	struct clk_rpmh *r = to_clk_rpmh(hw);
+
+	/*
+	 * RPMh clocks have a fixed rate. Return static rate.
+	 */
+	return prate / r->div;
+}
+
+static const struct clk_ops clk_rpmh_ops = {
+	.prepare	= clk_rpmh_prepare,
+	.unprepare	= clk_rpmh_unprepare,
+	.recalc_rate	= clk_rpmh_recalc_rate,
+};
+
+/* Resource name must match resource id present in cmd-db. */
+DEFINE_CLK_RPMH_ARC(sdm845, bi_tcxo, bi_tcxo_ao, "xo.lvl", 0x3, 2);
+DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk2, ln_bb_clk2_ao, "lnbclka2", 2);
+DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk3, ln_bb_clk3_ao, "lnbclka3", 2);
+DEFINE_CLK_RPMH_VRM(sdm845, rf_clk1, rf_clk1_ao, "rfclka1", 1);
+DEFINE_CLK_RPMH_VRM(sdm845, rf_clk2, rf_clk2_ao, "rfclka2", 1);
+DEFINE_CLK_RPMH_VRM(sdm845, rf_clk3, rf_clk3_ao, "rfclka3", 1);
+
+static struct clk_hw *sdm845_rpmh_clocks[] = {
+	[RPMH_CXO_CLK]		= &sdm845_bi_tcxo.hw,
+	[RPMH_CXO_CLK_A]	= &sdm845_bi_tcxo_ao.hw,
+	[RPMH_LN_BB_CLK2]	= &sdm845_ln_bb_clk2.hw,
+	[RPMH_LN_BB_CLK2_A]	= &sdm845_ln_bb_clk2_ao.hw,
+	[RPMH_LN_BB_CLK3]	= &sdm845_ln_bb_clk3.hw,
+	[RPMH_LN_BB_CLK3_A]	= &sdm845_ln_bb_clk3_ao.hw,
+	[RPMH_RF_CLK1]		= &sdm845_rf_clk1.hw,
+	[RPMH_RF_CLK1_A]	= &sdm845_rf_clk1_ao.hw,
+	[RPMH_RF_CLK2]		= &sdm845_rf_clk2.hw,
+	[RPMH_RF_CLK2_A]	= &sdm845_rf_clk2_ao.hw,
+	[RPMH_RF_CLK3]		= &sdm845_rf_clk3.hw,
+	[RPMH_RF_CLK3_A]	= &sdm845_rf_clk3_ao.hw,
+};
+
+static const struct clk_rpmh_desc clk_rpmh_sdm845 = {
+	.clks = sdm845_rpmh_clocks,
+	.num_clks = ARRAY_SIZE(sdm845_rpmh_clocks),
+};
+
+static struct clk_hw *of_clk_rpmh_hw_get(struct of_phandle_args *clkspec,
+					 void *data)
+{
+	struct clk_rpmh_desc *rpmh = data;
+	unsigned int idx = clkspec->args[0];
+
+	if (idx >= rpmh->num_clks) {
+		pr_err("%s: invalid index %u\n", __func__, idx);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return rpmh->clks[idx];
+}
+
+static int clk_rpmh_probe(struct platform_device *pdev)
+{
+	struct clk_hw **hw_clks;
+	struct clk_rpmh *rpmh_clk;
+	const struct clk_rpmh_desc *desc;
+	int ret, i;
+
+	desc = of_device_get_match_data(&pdev->dev);
+	if (!desc)
+		return -ENODEV;
+
+	hw_clks = desc->clks;
+
+	for (i = 0; i < desc->num_clks; i++) {
+		u32 res_addr;
+
+		rpmh_clk = to_clk_rpmh(hw_clks[i]);
+		res_addr = cmd_db_read_addr(rpmh_clk->res_name);
+		if (!res_addr) {
+			dev_err(&pdev->dev, "missing RPMh resource address for %s\n",
+				rpmh_clk->res_name);
+			return -ENODEV;
+		}
+		rpmh_clk->res_addr += res_addr;
+		rpmh_clk->dev = &pdev->dev;
+
+		ret = devm_clk_hw_register(&pdev->dev, hw_clks[i]);
+		if (ret) {
+			dev_err(&pdev->dev, "failed to register %s\n",
+				hw_clks[i]->init->name);
+			return ret;
+		}
+	}
+
+	/* typecast to silence compiler warning */
+	ret = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_rpmh_hw_get,
+					  (void *)desc);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add clock provider\n");
+		return ret;
+	}
+
+	dev_dbg(&pdev->dev, "Registered RPMh clocks\n");
+
+	return 0;
+}
+
+static const struct of_device_id clk_rpmh_match_table[] = {
+	{ .compatible = "qcom,sdm845-rpmh-clk", .data = &clk_rpmh_sdm845},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, clk_rpmh_match_table);
+
+static struct platform_driver clk_rpmh_driver = {
+	.probe		= clk_rpmh_probe,
+	.driver		= {
+		.name	= "clk-rpmh",
+		.of_match_table = clk_rpmh_match_table,
+	},
+};
+
+static int __init clk_rpmh_init(void)
+{
+	return platform_driver_register(&clk_rpmh_driver);
+}
+subsys_initcall(clk_rpmh_init);
+
+static void __exit clk_rpmh_exit(void)
+{
+	platform_driver_unregister(&clk_rpmh_driver);
+}
+module_exit(clk_rpmh_exit);
+
+MODULE_DESCRIPTION("QCOM RPMh Clock Driver");
+MODULE_LICENSE("GPL v2");