[RFC v3 11/11] clk: qcom: Add basic CPU clock driver for msm8996

[Rajendra Nayak]

This is a skeletal CPU clock driver, which adds support for the
CPU SS primary as well as secondary/alternate PLLs, and the
primary/secondary muxes.

This still has support missing for
1. CBF PLL and mux
2. ACD
3. APM

Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
---
 drivers/clk/qcom/Makefile       |   1 +
 drivers/clk/qcom/clk-cpu-8996.c | 408 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 409 insertions(+)
 create mode 100644 drivers/clk/qcom/clk-cpu-8996.c

diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 2a25f4e..407668d 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -10,6 +10,7 @@ clk-qcom-y += clk-branch.o
 clk-qcom-y += clk-regmap-divider.o
 clk-qcom-y += clk-regmap-mux.o
 clk-qcom-y += reset.o
+clk-qcom-y += clk-cpu-8996.o
 clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o
 
 obj-$(CONFIG_APQ_GCC_8084) += gcc-apq8084.o
diff --git a/drivers/clk/qcom/clk-cpu-8996.c b/drivers/clk/qcom/clk-cpu-8996.c
new file mode 100644
index 0000000..e690544
--- /dev/null
+++ b/drivers/clk/qcom/clk-cpu-8996.c
@@ -0,0 +1,408 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/cpu.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include "clk-alpha-pll.h"
+#include "clk-pll.h"
+#include "clk-regmap.h"
+#include "clk-regmap-mux.h"
+
+#define VCO(a, b, c) { \
+	.val = a,\
+	.min_freq = b,\
+	.max_freq = c,\
+}
+
+static const struct alpha_pll_config hfpll_config = {
+	.l = 60,
+	.config_ctl_val = 0x200D4828,
+	.config_ctl_hi_val = 0x006,
+	.pre_div_mask = BIT(12),
+	.post_div_mask = 0x3 << 8,
+	.main_output_mask = BIT(0),
+	.early_output_mask = BIT(3),
+};
+
+static struct clk_alpha_pll perfcl_pll = {
+	.offset = 0x80000,
+	.min_rate = 600000000,
+	.max_rate = 3000000000,
+	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_16BIT_ALPHA
+			| SUPPORTS_FSM_MODE,
+	.clkr.hw.init = &(struct clk_init_data){
+		.name = "perfcl_pll",
+		.parent_names = (const char *[]){ "xo_board" },
+		.num_parents = 1,
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static struct clk_alpha_pll pwrcl_pll = {
+	.offset = 0x0,
+	.min_rate = 600000000,
+	.max_rate = 3000000000,
+	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_16BIT_ALPHA
+			| SUPPORTS_FSM_MODE,
+	.clkr.hw.init = &(struct clk_init_data){
+		.name = "pwrcl_pll",
+		.parent_names = (const char *[]){ "xo_board" },
+		.num_parents = 1,
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static const struct pll_vco alt_pll_vco_modes[] = {
+	VCO(3,  250000000,  500000000),
+	VCO(2,  500000000,  750000000),
+	VCO(1,  750000000, 1000000000),
+	VCO(0, 1000000000, 2150400000),
+};
+
+static const struct alpha_pll_config altpll_config = {
+	.l = 16,
+	.vco_val = 0x3 << 20,
+	.vco_mask = 0x3 << 20,
+	.config_ctl_val = 0x4001051B,
+	.post_div_mask = 0x3 << 8,
+	.post_div_val = 0x1,
+	.main_output_mask = BIT(0),
+	.early_output_mask = BIT(3),
+};
+
+static struct clk_alpha_pll perfcl_alt_pll = {
+	.offset = 0x80100,
+	.vco_table = alt_pll_vco_modes,
+	.num_vco = ARRAY_SIZE(alt_pll_vco_modes),
+	.flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "perfcl_alt_pll",
+		.parent_names = (const char *[]){ "xo_board" },
+		.num_parents = 1,
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static struct clk_alpha_pll pwrcl_alt_pll = {
+	.offset = 0x100,
+	.vco_table = alt_pll_vco_modes,
+	.num_vco = ARRAY_SIZE(alt_pll_vco_modes),
+	.flags = SUPPORTS_OFFLINE_REQ | SUPPORTS_FSM_MODE,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "pwrcl_alt_pll",
+		.parent_names = (const char *[]){ "xo_board" },
+		.num_parents = 1,
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static struct clk_regmap_mux pwrcl_pmux = {
+	.reg = 0x40,
+	.shift = 0,
+	.width = 2,
+	.table = (u32 []){0, 1, 3},
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "pwrcl_pmux",
+		.parent_names = (const char *[]){
+			"pwrcl_smux",
+			"pwrcl_pll",
+			"pwrcl_alt_pll",
+		},
+		.num_parents = 3,
+		.ops = &clk_regmap_mux_closest_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_regmap_mux pwrcl_smux = {
+	.reg = 0x40,
+	.shift = 2,
+	.width = 2,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "pwrcl_smux",
+		.parent_names = (const char *[]){
+			"xo_board",
+			"pwrcl_pll_main",
+			"sys_apcscbf_clk",
+			"sys_apcsaux_clk",
+		},
+		.num_parents = 4,
+		.ops = &clk_regmap_mux_closest_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_regmap_mux perfcl_pmux = {
+	.reg = 0x80040,
+	.shift = 0,
+	.width = 2,
+	.table = (u32 []){0, 1, 3},
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "perfcl_pmux",
+		.parent_names = (const char *[]){
+			"perfcl_smux",
+			"perfcl_pll",
+			"perfcl_alt_pll",
+		},
+		.num_parents = 3,
+		.ops = &clk_regmap_mux_closest_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_regmap_mux perfcl_smux = {
+	.reg = 0x80040,
+	.shift = 2,
+	.width = 2,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "perfcl_smux",
+		.parent_names = (const char *[]){
+			"xo_board",
+			"perfcl_pll_main",
+			"sys_apcscbf_clk",
+			"sys_apcsaux_clk",
+		},
+		.num_parents = 4,
+		.ops = &clk_regmap_mux_closest_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+struct clk_cpu_8996 {
+	struct clk_hw *alt_clk;
+	struct clk_hw *pll;
+	struct clk_regmap clkr;
+};
+
+static inline struct clk_cpu_8996 *to_clk_cpu_8996(struct clk_hw *hw)
+{
+	return container_of(to_clk_regmap(hw), struct clk_cpu_8996, clkr);
+}
+
+static int clk_cpu_8996_set_rate(struct clk_hw *hw, unsigned long rate,
+				 unsigned long prate)
+{
+	int ret;
+	struct clk_cpu_8996 *cpuclk = to_clk_cpu_8996(hw);
+	struct clk *alt_clk, *pll, *parent;
+
+	alt_clk = clk_hw_get_clk(cpuclk->alt_clk);
+	pll = clk_hw_get_clk(cpuclk->pll);
+	parent = clk_hw_get_clk(clk_hw_get_parent(hw));
+
+	/* Switch parent to alt clk */
+	if (cpuclk->alt_clk) {
+		ret = clk_set_parent(parent, alt_clk);
+		if (ret)
+			return ret;
+	}
+
+	/* Set the PLL to new rate */
+	ret = clk_set_rate(pll, rate);
+	if (ret)
+		goto error;
+
+	/* Switch back to primary pll */
+	if (cpuclk->alt_clk) {
+		ret = clk_set_parent(parent, pll);
+		if (ret)
+			goto error;
+	}
+	return 0;
+
+error:
+	if (cpuclk->alt_clk)
+		clk_set_parent(parent, pll);
+
+	return ret;
+}
+
+static unsigned long clk_cpu_8996_recalc_rate(struct clk_hw *hw,
+					      unsigned long prate)
+{
+	return clk_hw_get_rate(clk_hw_get_parent(hw));
+}
+
+static long clk_cpu_8996_round_rate(struct clk_hw *hw, unsigned long rate,
+				    unsigned long *prate)
+{
+	return clk_hw_round_rate(clk_hw_get_parent(hw), rate);
+}
+
+static struct clk_ops clk_cpu_8996_ops = {
+	.set_rate = clk_cpu_8996_set_rate,
+	.recalc_rate = clk_cpu_8996_recalc_rate,
+	.round_rate = clk_cpu_8996_round_rate,
+};
+
+static struct clk_cpu_8996 pwrcl_clk = {
+	.alt_clk = &pwrcl_alt_pll.clkr.hw,
+	.pll = &pwrcl_pll.clkr.hw,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "pwrcl_clk",
+		.parent_names = (const char *[]){ "pwrcl_pmux" },
+		.num_parents = 1,
+		.ops = &clk_cpu_8996_ops,
+	},
+};
+
+static struct clk_cpu_8996 perfcl_clk = {
+	.alt_clk = &perfcl_alt_pll.clkr.hw,
+	.pll = &perfcl_pll.clkr.hw,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "perfcl_clk",
+		.parent_names = (const char *[]){ "perfcl_pmux" },
+		.num_parents = 1,
+		.ops = &clk_cpu_8996_ops,
+	},
+};
+
+static const struct regmap_config cpu_msm8996_regmap_config = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= 0x80210,
+	.fast_io		= true,
+	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
+};
+
+static const struct of_device_id match_table[] = {
+	{ .compatible = "qcom,cpu-clk-msm8996" },
+	{}
+};
+
+#define cluster_clk_register(dev, clk, clkr) { \
+	clk = devm_clk_register_regmap(dev, clkr); \
+	if (IS_ERR(clk)) \
+		return PTR_ERR(clk); }
+
+#define cpu_clk_register_fixed(dev, clk, name, pname, flags, m, n) { \
+	clk = clk_register_fixed_factor(dev, name, pname, flags, m, n); \
+	if (IS_ERR(clk)) \
+		return PTR_ERR(clk); }
+
+#define cpu_set_rate(dev, clk, rate) { \
+	if (clk_set_rate(clk, rate)) \
+		dev_err(dev, "Failed to set " #clk " to " #rate "\n"); }
+
+#define cpu_prepare_enable(dev, clk) { \
+	if (clk_prepare_enable(clk)) \
+		dev_err(dev, "Failed to enable " #clk "\n"); }
+
+#define cpu_set_parent(dev, clk, parent) { \
+	if (clk_set_parent(clk, parent)) \
+		dev_err(dev, "Failed to set parent for " #clk "\n"); }
+
+struct clk *pwr_clk, *perf_clk;
+
+static int register_cpu_clocks(struct device *dev, struct regmap *regmap)
+{
+	struct clk *perf_alt_pll, *pwr_alt_pll, *perf_pll, *pwr_pll;
+	struct clk *perf_pmux, *perf_smux, *pwr_pmux, *pwr_smux;
+	struct clk *perf_pll_main, *pwr_pll_main;
+
+	/* register PLLs */
+	cluster_clk_register(dev, perf_pll, &perfcl_pll.clkr);
+	cluster_clk_register(dev, pwr_pll, &pwrcl_pll.clkr);
+	cluster_clk_register(dev, perf_alt_pll, &perfcl_alt_pll.clkr);
+	cluster_clk_register(dev, pwr_alt_pll, &pwrcl_alt_pll.clkr);
+
+	/* register MUXs */
+	cluster_clk_register(dev, perf_pmux, &perfcl_pmux.clkr);
+	cluster_clk_register(dev, perf_smux, &perfcl_smux.clkr);
+	cluster_clk_register(dev, pwr_pmux, &pwrcl_pmux.clkr);
+	cluster_clk_register(dev, pwr_smux, &pwrcl_smux.clkr);
+
+	/* register Fixed clks */
+	cpu_clk_register_fixed(dev, perf_pll_main, "perfcl_pll_main",
+			       "perfcl_pll", CLK_SET_RATE_PARENT, 1, 2);
+	cpu_clk_register_fixed(dev, pwr_pll_main, "pwrcl_pll_main",
+			       "pwrcl_pll", CLK_SET_RATE_PARENT, 1, 2);
+
+	/* Register CPU clks */
+	cluster_clk_register(dev, perf_clk, &perfcl_clk.clkr);
+	cluster_clk_register(dev, pwr_clk, &pwrcl_clk.clkr);
+
+	/* Initialise the PLLs */
+	clk_alpha_pll_configure(&perfcl_pll, regmap, &hfpll_config);
+	clk_alpha_pll_configure(&pwrcl_pll, regmap, &hfpll_config);
+	clk_alpha_pll_configure(&perfcl_alt_pll, regmap, &altpll_config);
+	clk_alpha_pll_configure(&pwrcl_alt_pll, regmap, &altpll_config);
+
+	/* Enable all PLLs and alt PLLs */
+	cpu_prepare_enable(dev, perf_pll);
+	cpu_prepare_enable(dev, pwr_pll);
+	cpu_prepare_enable(dev, perf_alt_pll);
+	cpu_prepare_enable(dev, pwr_alt_pll);
+
+	/* Init MUXes with default parents */
+	cpu_set_parent(dev, perf_pmux, perf_pll);
+	cpu_set_parent(dev, pwr_pmux, pwr_pll);
+	cpu_set_parent(dev, perf_smux, perf_pll_main);
+	cpu_set_parent(dev, pwr_smux, pwr_pll_main);
+
+	return 0;
+}
+
+static int qcom_cpu_clk_msm8996_driver_probe(struct platform_device *pdev)
+{
+	int ret;
+	void __iomem *base;
+	struct resource *res;
+	struct clk_onecell_data *data;
+	struct device *dev = &pdev->dev;
+	struct regmap *regmap_cpu;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->clks = devm_kcalloc(dev, 3, sizeof(struct clk *), GFP_KERNEL);
+	if (!data->clks)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap_cpu = devm_regmap_init_mmio(dev, base,
+					   &cpu_msm8996_regmap_config);
+	if (IS_ERR(regmap_cpu))
+		return PTR_ERR(regmap_cpu);
+
+	ret = register_cpu_clocks(dev, regmap_cpu);
+	if (ret)
+		return ret;
+
+	data->clks[0] = pwr_clk;
+	data->clks[1] = perf_clk;
+	data->clk_num = 2;
+
+	return of_clk_add_provider(dev->of_node, of_clk_src_onecell_get, data);
+}
+
+static struct platform_driver qcom_cpu_clk_msm8996_driver = {
+	.probe = qcom_cpu_clk_msm8996_driver_probe,
+	.driver = {
+		.name = "qcom-cpu-clk-msm8996",
+		.of_match_table = match_table,
+	},
+};
+
+builtin_platform_driver(qcom_cpu_clk_msm8996_driver);
-- 
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