[PATCH v3 2/2] clk: qcom: clk-rpmh: Add QCOM RPMh clock driver

[Taniya Das <tdas@codeaurora.org>]

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

Signed-off-by: David Collins <collinsd@codeaurora.org>
Signed-off-by: Amit Nischal <anischal@codeaurora.org>
---
 drivers/clk/qcom/Kconfig    |   9 ++
 drivers/clk/qcom/Makefile   |   1 +
 drivers/clk/qcom/clk-rpmh.c | 367 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 377 insertions(+)
 create mode 100644 drivers/clk/qcom/clk-rpmh.c

diff --git a/drivers/clk/qcom/Kconfig b/drivers/clk/qcom/Kconfig
index fbf4532..63c3372 100644
--- a/drivers/clk/qcom/Kconfig
+++ b/drivers/clk/qcom/Kconfig
@@ -112,6 +112,15 @@ config IPQ_GCC_8074
 	  i2c, USB, SD/eMMC, etc. Select this for the root clock
 	  of ipq8074.

+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 MSM_GCC_8660
 	tristate "MSM8660 Global Clock Controller"
 	depends on COMMON_CLK_QCOM
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 230332c..b2b5babf 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -36,5 +36,6 @@ 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_SPMI_PMIC_CLKDIV) += clk-spmi-pmic-div.o
diff --git a/drivers/clk/qcom/clk-rpmh.c b/drivers/clk/qcom/clk-rpmh.c
new file mode 100644
index 0000000..fa61284
--- /dev/null
+++ b/drivers/clk/qcom/clk-rpmh.c
@@ -0,0 +1,367 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clk.h>
+#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
+#define CLK_RPMH_APPS_RSC_AO_STATE_MASK (BIT(RPMH_WAKE_ONLY_STATE) | \
+					 BIT(RPMH_ACTIVE_ONLY_STATE))
+#define CLK_RPMH_APPS_RSC_STATE_MASK (BIT(RPMH_WAKE_ONLY_STATE) | \
+				      BIT(RPMH_ACTIVE_ONLY_STATE) | \
+				      BIT(RPMH_SLEEP_STATE))
+struct clk_rpmh {
+	struct clk_hw hw;
+	const char *res_name;
+	u32 res_addr;
+	u32 res_en_offset;
+	u32 res_on_val;
+	u32 res_off_val;
+	u32 state;
+	u32 aggr_state;
+	u32 last_sent_aggr_state;
+	u32 valid_state_mask;
+	struct rpmh_client *rpmh_client;
+	struct device *dev;
+	struct clk_rpmh *peer;
+	unsigned long rate;
+};
+
+struct rpmh_cc {
+	struct clk_onecell_data data;
+	struct clk *clks[];
+};
+
+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, _res_off, _rate)	\
+	static struct clk_rpmh _platform##_##_name_active;		      \
+	static struct clk_rpmh _platform##_##_name = {			      \
+		.res_name = _res_name,					      \
+		.res_en_offset = _res_en_offset,			      \
+		.res_on_val = _res_on,					      \
+		.res_off_val = _res_off,				      \
+		.rate = _rate,						      \
+		.peer = &_platform##_##_name_active,			      \
+		.valid_state_mask = CLK_RPMH_APPS_RSC_STATE_MASK,	      \
+		.hw.init = &(struct clk_init_data){			      \
+			.ops = &clk_rpmh_ops,			              \
+			.name = #_name,					      \
+		},							      \
+	};								      \
+	static struct clk_rpmh _platform##_##_name_active = {		      \
+		.res_name = _res_name,					      \
+		.res_en_offset = _res_en_offset,			      \
+		.res_on_val = _res_on,					      \
+		.res_off_val = _res_off,				      \
+		.rate = _rate,						      \
+		.peer = &_platform##_##_name,				      \
+		.valid_state_mask = CLK_RPMH_APPS_RSC_AO_STATE_MASK,	      \
+		.hw.init = &(struct clk_init_data){			      \
+			.ops = &clk_rpmh_ops,				      \
+			.name = #_name_active,				      \
+		},							      \
+	}
+
+#define DEFINE_CLK_RPMH_ARC(_platform, _name, _name_active, _res_name, \
+			    _res_on, _res_off, _rate) \
+	__DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,	\
+			  CLK_RPMH_ARC_EN_OFFSET, _res_on, _res_off, _rate)
+
+#define DEFINE_CLK_RPMH_VRM(_platform, _name, _name_active, _res_name,	\
+			    _rate)					 \
+	__DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,     \
+			  CLK_RPMH_VRM_EN_OFFSET, true, false, _rate)
+
+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 = 0;
+
+	cmd.addr = c->res_addr + c->res_en_offset;
+	cmd_state = c->aggr_state;
+	on_val = c->res_on_val;
+
+	for (; state <= RPMH_ACTIVE_ONLY_STATE; state++) {
+		if (has_state_changed(c, state)) {
+			cmd.data = (cmd_state & BIT(state)) ? on_val : 0;
+			ret = rpmh_write_async(c->rpmh_client, 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;
+}
+
+static int clk_rpmh_aggregate_state_send_command(struct clk_rpmh *c,
+						bool enable)
+{
+	int ret;
+
+	/* Update state and aggregate state values based on enable value. */
+	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 && enable) {
+		c->state = 0;
+	} else if (ret) {
+		c->state = c->valid_state_mask;
+		WARN(1, "clk: %s failed to disable\n", c->res_name);
+	}
+
+	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);
+
+	if (c->state)
+		goto out;
+
+	ret = clk_rpmh_aggregate_state_send_command(c, true);
+out:
+	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);
+
+	if (!c->state)
+		goto out;
+
+	clk_rpmh_aggregate_state_send_command(c, false);
+out:
+	mutex_unlock(&rpmh_clk_lock);
+	return;
+};
+
+static unsigned long clk_rpmh_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct clk_rpmh *r = to_clk_rpmh(hw);
+
+	/*
+	 * RPMh clocks have a fixed rate. Return static rate set
+	 * at init time.
+	 */
+	return r->rate;
+}
+
+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, 0x0, 19200000);
+DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk2, ln_bb_clk2_ao, "lnbclka2", 19200000);
+DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk3, ln_bb_clk3_ao, "lnbclka3", 19200000);
+DEFINE_CLK_RPMH_VRM(sdm845, rf_clk1, rf_clk1_ao, "rfclka1", 38400000);
+DEFINE_CLK_RPMH_VRM(sdm845, rf_clk2, rf_clk2_ao, "rfclka2", 38400000);
+DEFINE_CLK_RPMH_VRM(sdm845, rf_clk3, rf_clk3_ao, "rfclka3", 38400000);
+
+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 int clk_rpmh_probe(struct platform_device *pdev)
+{
+	struct clk **clks;
+	struct clk *clk;
+	struct rpmh_cc *rcc;
+	struct clk_onecell_data *data;
+	struct clk_hw **hw_clks;
+	struct clk_rpmh *rpmh_clk;
+	const struct clk_rpmh_desc *desc;
+	struct rpmh_client *rpmh_client;
+	struct device *dev;
+	size_t num_clks, i;
+	int ret;
+
+	dev = &pdev->dev;
+
+	ret = cmd_db_ready();
+	if (ret) {
+		if (ret != -EPROBE_DEFER) {
+			dev_err(dev, "Command DB not available (%d)\n",	ret);
+			goto fail;
+		}
+		return ret;
+	}
+
+	rpmh_client = rpmh_get_client(pdev);
+	if (IS_ERR(rpmh_client)) {
+		ret = PTR_ERR(rpmh_client);
+		dev_err(dev, "Failed to request RPMh client, ret=%d\n",	ret);
+		return ret;
+	}
+
+	desc = of_device_get_match_data(&pdev->dev);
+	hw_clks = desc->clks;
+	num_clks = desc->num_clks;
+
+	rcc = devm_kzalloc(&pdev->dev, sizeof(*rcc) + sizeof(*clks) * num_clks,
+			   GFP_KERNEL);
+	if (!rcc) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	clks = rcc->clks;
+	data = &rcc->data;
+	data->clks = clks;
+	data->clk_num = num_clks;
+
+	for (i = 0; i < num_clks; i++) {
+		rpmh_clk = to_clk_rpmh(hw_clks[i]);
+		rpmh_clk->res_addr = cmd_db_read_addr(rpmh_clk->res_name);
+		if (!rpmh_clk->res_addr) {
+			dev_err(dev, "missing RPMh resource address for %s\n",
+					rpmh_clk->res_name);
+			ret = -ENODEV;
+			goto err;
+		}
+
+		rpmh_clk->rpmh_client = rpmh_client;
+
+		clk = devm_clk_register(&pdev->dev, hw_clks[i]);
+		if (IS_ERR(clk)) {
+			ret = PTR_ERR(clk);
+			dev_err(dev, "failed to register %s\n",
+					hw_clks[i]->init->name);
+			goto err;
+		}
+
+		clks[i] = clk;
+		rpmh_clk->dev = &pdev->dev;
+	}
+
+	ret = of_clk_add_provider(pdev->dev.of_node, of_clk_src_onecell_get,
+				  data);
+	if (ret) {
+		dev_err(dev, "Failed to add clock provider\n");
+		goto err;
+	}
+
+	dev_dbg(dev, "Registered RPMh clocks\n");
+
+	return 0;
+err:
+	if (rpmh_client)
+		rpmh_release(rpmh_client);
+fail:
+	dev_err(dev, "Error registering RPMh Clock driver (%d)\n", ret);
+	return ret;
+}
+
+static int clk_rpmh_remove(struct platform_device *pdev)
+{
+	const struct clk_rpmh_desc *desc =
+			of_device_get_match_data(&pdev->dev);
+	struct clk_hw **hw_clks = desc->clks;
+	struct clk_rpmh *rpmh_clk = to_clk_rpmh(hw_clks[0]);
+
+	rpmh_release(rpmh_clk->rpmh_client);
+	of_clk_del_provider(pdev->dev.of_node);
+
+	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,
+	.remove		= clk_rpmh_remove,
+	.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");
--
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