Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 629 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-cpu-8996.c b/drivers/clk/qcom/clk-cpu-8996.c
new file mode 100644
index 0000000000..72689448a6
--- /dev/null
+++ b/drivers/clk/qcom/clk-cpu-8996.c
@@ -0,0 +1,629 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+/*
+ * Each of the CPU clusters (Power and Perf) on msm8996 are
+ * clocked via 2 PLLs, a primary and alternate. There are also
+ * 2 Mux'es, a primary and secondary all connected together
+ * as shown below
+ *
+ *                              +-------+
+ *               XO             |       |
+ *           +------------------>0      |
+ *               SYS_APCS_AUX   |       |
+ *           +------------------>3      |
+ *                              |       |
+ *                    PLL/2     | SMUX  +----+
+ *                      +------->1      |    |
+ *                      |       |       |    |
+ *                      |       +-------+    |    +-------+
+ *                      |                    +---->0      |
+ *                      |                         |       |
+ * +---------------+    |             +----------->1      | CPU clk
+ * |Primary PLL    +----+ PLL_EARLY   |           |       +------>
+ * |               +------+-----------+    +------>2 PMUX |
+ * +---------------+      |                |      |       |
+ *                        |   +------+     |   +-->3      |
+ *                        +--^+  ACD +-----+   |  +-------+
+ * +---------------+          +------+         |
+ * |Alt PLL        |                           |
+ * |               +---------------------------+
+ * +---------------+         PLL_EARLY
+ *
+ * The primary PLL is what drives the CPU clk, except for times
+ * when we are reprogramming the PLL itself (for rate changes) when
+ * we temporarily switch to an alternate PLL.
+ *
+ * The primary PLL operates on a single VCO range, between 600MHz
+ * and 3GHz. However the CPUs do support OPPs with frequencies
+ * between 300MHz and 600MHz. In order to support running the CPUs
+ * at those frequencies we end up having to lock the PLL at twice
+ * the rate and drive the CPU clk via the PLL/2 output and SMUX.
+ *
+ * So for frequencies above 600MHz we follow the following path
+ *  Primary PLL --> PLL_EARLY --> PMUX(1) --> CPU clk
+ * and for frequencies between 300MHz and 600MHz we follow
+ *  Primary PLL --> PLL/2 --> SMUX(1) --> PMUX(0) --> CPU clk
+ *
+ * ACD stands for Adaptive Clock Distribution and is used to
+ * detect voltage droops.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <soc/qcom/kryo-l2-accessors.h>
+
+#include <asm/cputype.h>
+
+#include "clk-alpha-pll.h"
+#include "clk-regmap.h"
+#include "clk-regmap-mux.h"
+
+enum _pmux_input {
+	SMUX_INDEX = 0,
+	PLL_INDEX,
+	ACD_INDEX,
+	ALT_INDEX,
+	NUM_OF_PMUX_INPUTS
+};
+
+#define DIV_2_THRESHOLD		600000000
+#define PWRCL_REG_OFFSET 0x0
+#define PERFCL_REG_OFFSET 0x80000
+#define MUX_OFFSET	0x40
+#define CLK_CTL_OFFSET 0x44
+#define CLK_CTL_AUTO_CLK_SEL BIT(8)
+#define ALT_PLL_OFFSET	0x100
+#define SSSCTL_OFFSET 0x160
+#define PSCTL_OFFSET 0x164
+
+#define PMUX_MASK	0x3
+#define MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK GENMASK(5, 4)
+#define MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL \
+	FIELD_PREP(MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK, 0x03)
+
+static const u8 prim_pll_regs[PLL_OFF_MAX_REGS] = {
+	[PLL_OFF_L_VAL] = 0x04,
+	[PLL_OFF_ALPHA_VAL] = 0x08,
+	[PLL_OFF_USER_CTL] = 0x10,
+	[PLL_OFF_CONFIG_CTL] = 0x18,
+	[PLL_OFF_CONFIG_CTL_U] = 0x1c,
+	[PLL_OFF_TEST_CTL] = 0x20,
+	[PLL_OFF_TEST_CTL_U] = 0x24,
+	[PLL_OFF_STATUS] = 0x28,
+};
+
+static const u8 alt_pll_regs[PLL_OFF_MAX_REGS] = {
+	[PLL_OFF_L_VAL] = 0x04,
+	[PLL_OFF_ALPHA_VAL] = 0x08,
+	[PLL_OFF_USER_CTL] = 0x10,
+	[PLL_OFF_CONFIG_CTL] = 0x18,
+	[PLL_OFF_TEST_CTL] = 0x20,
+	[PLL_OFF_STATUS] = 0x28,
+};
+
+/* PLLs */
+
+static const struct alpha_pll_config hfpll_config = {
+	.l = 54,
+	.config_ctl_val = 0x200d4828,
+	.config_ctl_hi_val = 0x006,
+	.test_ctl_val = 0x1c000000,
+	.test_ctl_hi_val = 0x00004000,
+	.pre_div_mask = BIT(12),
+	.post_div_mask = 0x3 << 8,
+	.post_div_val = 0x1 << 8,
+	.main_output_mask = BIT(0),
+	.early_output_mask = BIT(3),
+};
+
+static const struct clk_parent_data pll_parent[] = {
+	{ .fw_name = "xo" },
+};
+
+static struct clk_alpha_pll pwrcl_pll = {
+	.offset = PWRCL_REG_OFFSET,
+	.regs = prim_pll_regs,
+	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
+	.clkr.hw.init = &(struct clk_init_data){
+		.name = "pwrcl_pll",
+		.parent_data = pll_parent,
+		.num_parents = ARRAY_SIZE(pll_parent),
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static struct clk_alpha_pll perfcl_pll = {
+	.offset = PERFCL_REG_OFFSET,
+	.regs = prim_pll_regs,
+	.flags = SUPPORTS_DYNAMIC_UPDATE | SUPPORTS_FSM_MODE,
+	.clkr.hw.init = &(struct clk_init_data){
+		.name = "perfcl_pll",
+		.parent_data = pll_parent,
+		.num_parents = ARRAY_SIZE(pll_parent),
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static struct clk_fixed_factor pwrcl_pll_postdiv = {
+	.mult = 1,
+	.div = 2,
+	.hw.init = &(struct clk_init_data){
+		.name = "pwrcl_pll_postdiv",
+		.parent_data = &(const struct clk_parent_data){
+			.hw = &pwrcl_pll.clkr.hw
+		},
+		.num_parents = 1,
+		.ops = &clk_fixed_factor_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_fixed_factor perfcl_pll_postdiv = {
+	.mult = 1,
+	.div = 2,
+	.hw.init = &(struct clk_init_data){
+		.name = "perfcl_pll_postdiv",
+		.parent_data = &(const struct clk_parent_data){
+			.hw = &perfcl_pll.clkr.hw
+		},
+		.num_parents = 1,
+		.ops = &clk_fixed_factor_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_fixed_factor perfcl_pll_acd = {
+	.mult = 1,
+	.div = 1,
+	.hw.init = &(struct clk_init_data){
+		.name = "perfcl_pll_acd",
+		.parent_data = &(const struct clk_parent_data){
+			.hw = &perfcl_pll.clkr.hw
+		},
+		.num_parents = 1,
+		.ops = &clk_fixed_factor_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_fixed_factor pwrcl_pll_acd = {
+	.mult = 1,
+	.div = 1,
+	.hw.init = &(struct clk_init_data){
+		.name = "pwrcl_pll_acd",
+		.parent_data = &(const struct clk_parent_data){
+			.hw = &pwrcl_pll.clkr.hw
+		},
+		.num_parents = 1,
+		.ops = &clk_fixed_factor_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+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 << 8,
+	.main_output_mask = BIT(0),
+	.early_output_mask = BIT(3),
+};
+
+static struct clk_alpha_pll pwrcl_alt_pll = {
+	.offset = PWRCL_REG_OFFSET + ALT_PLL_OFFSET,
+	.regs = alt_pll_regs,
+	.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_data = pll_parent,
+		.num_parents = ARRAY_SIZE(pll_parent),
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+static struct clk_alpha_pll perfcl_alt_pll = {
+	.offset = PERFCL_REG_OFFSET + ALT_PLL_OFFSET,
+	.regs = alt_pll_regs,
+	.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_data = pll_parent,
+		.num_parents = ARRAY_SIZE(pll_parent),
+		.ops = &clk_alpha_pll_hwfsm_ops,
+	},
+};
+
+struct clk_cpu_8996_pmux {
+	u32	reg;
+	struct notifier_block nb;
+	struct clk_regmap clkr;
+};
+
+static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
+			       void *data);
+
+#define to_clk_cpu_8996_pmux_nb(_nb) \
+	container_of(_nb, struct clk_cpu_8996_pmux, nb)
+
+static inline struct clk_cpu_8996_pmux *to_clk_cpu_8996_pmux_hw(struct clk_hw *hw)
+{
+	return container_of(to_clk_regmap(hw), struct clk_cpu_8996_pmux, clkr);
+}
+
+static u8 clk_cpu_8996_pmux_get_parent(struct clk_hw *hw)
+{
+	struct clk_regmap *clkr = to_clk_regmap(hw);
+	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_hw(hw);
+	u32 val;
+
+	regmap_read(clkr->regmap, cpuclk->reg, &val);
+
+	return FIELD_GET(PMUX_MASK, val);
+}
+
+static int clk_cpu_8996_pmux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_regmap *clkr = to_clk_regmap(hw);
+	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_hw(hw);
+	u32 val;
+
+	val = FIELD_PREP(PMUX_MASK, index);
+
+	return regmap_update_bits(clkr->regmap, cpuclk->reg, PMUX_MASK, val);
+}
+
+static int clk_cpu_8996_pmux_determine_rate(struct clk_hw *hw,
+					   struct clk_rate_request *req)
+{
+	struct clk_hw *parent;
+
+	if (req->rate < (DIV_2_THRESHOLD / 2))
+		return -EINVAL;
+
+	if (req->rate < DIV_2_THRESHOLD)
+		parent = clk_hw_get_parent_by_index(hw, SMUX_INDEX);
+	else
+		parent = clk_hw_get_parent_by_index(hw, ACD_INDEX);
+	if (!parent)
+		return -EINVAL;
+
+	req->best_parent_rate = clk_hw_round_rate(parent, req->rate);
+	req->best_parent_hw = parent;
+
+	return 0;
+}
+
+static const struct clk_ops clk_cpu_8996_pmux_ops = {
+	.set_parent = clk_cpu_8996_pmux_set_parent,
+	.get_parent = clk_cpu_8996_pmux_get_parent,
+	.determine_rate = clk_cpu_8996_pmux_determine_rate,
+};
+
+static const struct parent_map smux_parent_map[] = {
+	{ .cfg = 0, }, /* xo */
+	{ .cfg = 1, }, /* pll */
+	{ .cfg = 3, }, /* sys_apcs_aux */
+};
+
+static const struct clk_parent_data pwrcl_smux_parents[] = {
+	{ .fw_name = "xo" },
+	{ .hw = &pwrcl_pll_postdiv.hw },
+	{ .fw_name = "sys_apcs_aux" },
+};
+
+static const struct clk_parent_data perfcl_smux_parents[] = {
+	{ .fw_name = "xo" },
+	{ .hw = &perfcl_pll_postdiv.hw },
+	{ .fw_name = "sys_apcs_aux" },
+};
+
+static struct clk_regmap_mux pwrcl_smux = {
+	.reg = PWRCL_REG_OFFSET + MUX_OFFSET,
+	.shift = 2,
+	.width = 2,
+	.parent_map = smux_parent_map,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "pwrcl_smux",
+		.parent_data = pwrcl_smux_parents,
+		.num_parents = ARRAY_SIZE(pwrcl_smux_parents),
+		.ops = &clk_regmap_mux_closest_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_regmap_mux perfcl_smux = {
+	.reg = PERFCL_REG_OFFSET + MUX_OFFSET,
+	.shift = 2,
+	.width = 2,
+	.parent_map = smux_parent_map,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "perfcl_smux",
+		.parent_data = perfcl_smux_parents,
+		.num_parents = ARRAY_SIZE(perfcl_smux_parents),
+		.ops = &clk_regmap_mux_closest_ops,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static const struct clk_hw *pwrcl_pmux_parents[] = {
+	[SMUX_INDEX] = &pwrcl_smux.clkr.hw,
+	[PLL_INDEX] = &pwrcl_pll.clkr.hw,
+	[ACD_INDEX] = &pwrcl_pll_acd.hw,
+	[ALT_INDEX] = &pwrcl_alt_pll.clkr.hw,
+};
+
+static const struct clk_hw *perfcl_pmux_parents[] = {
+	[SMUX_INDEX] = &perfcl_smux.clkr.hw,
+	[PLL_INDEX] = &perfcl_pll.clkr.hw,
+	[ACD_INDEX] = &perfcl_pll_acd.hw,
+	[ALT_INDEX] = &perfcl_alt_pll.clkr.hw,
+};
+
+static struct clk_cpu_8996_pmux pwrcl_pmux = {
+	.reg = PWRCL_REG_OFFSET + MUX_OFFSET,
+	.nb.notifier_call = cpu_clk_notifier_cb,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "pwrcl_pmux",
+		.parent_hws = pwrcl_pmux_parents,
+		.num_parents = ARRAY_SIZE(pwrcl_pmux_parents),
+		.ops = &clk_cpu_8996_pmux_ops,
+		/* CPU clock is critical and should never be gated */
+		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
+	},
+};
+
+static struct clk_cpu_8996_pmux perfcl_pmux = {
+	.reg = PERFCL_REG_OFFSET + MUX_OFFSET,
+	.nb.notifier_call = cpu_clk_notifier_cb,
+	.clkr.hw.init = &(struct clk_init_data) {
+		.name = "perfcl_pmux",
+		.parent_hws = perfcl_pmux_parents,
+		.num_parents = ARRAY_SIZE(perfcl_pmux_parents),
+		.ops = &clk_cpu_8996_pmux_ops,
+		/* CPU clock is critical and should never be gated */
+		.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL,
+	},
+};
+
+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 struct clk_hw *cpu_msm8996_hw_clks[] = {
+	&pwrcl_pll_postdiv.hw,
+	&perfcl_pll_postdiv.hw,
+	&pwrcl_pll_acd.hw,
+	&perfcl_pll_acd.hw,
+};
+
+static struct clk_regmap *cpu_msm8996_clks[] = {
+	&pwrcl_pll.clkr,
+	&perfcl_pll.clkr,
+	&pwrcl_alt_pll.clkr,
+	&perfcl_alt_pll.clkr,
+	&pwrcl_smux.clkr,
+	&perfcl_smux.clkr,
+	&pwrcl_pmux.clkr,
+	&perfcl_pmux.clkr,
+};
+
+static void qcom_cpu_clk_msm8996_acd_init(struct regmap *regmap);
+
+static int qcom_cpu_clk_msm8996_register_clks(struct device *dev,
+					      struct regmap *regmap)
+{
+	int i, ret;
+
+	/* Select GPLL0 for 300MHz for both clusters */
+	regmap_write(regmap, PERFCL_REG_OFFSET + MUX_OFFSET, 0xc);
+	regmap_write(regmap, PWRCL_REG_OFFSET + MUX_OFFSET, 0xc);
+
+	/* Ensure write goes through before PLLs are reconfigured */
+	udelay(5);
+
+	/* Set the auto clock sel always-on source to GPLL0/2 (300MHz) */
+	regmap_update_bits(regmap, PWRCL_REG_OFFSET + MUX_OFFSET,
+			   MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK,
+			   MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL);
+	regmap_update_bits(regmap, PERFCL_REG_OFFSET + MUX_OFFSET,
+			   MUX_AUTO_CLK_SEL_ALWAYS_ON_MASK,
+			   MUX_AUTO_CLK_SEL_ALWAYS_ON_GPLL0_SEL);
+
+	clk_alpha_pll_configure(&pwrcl_pll, regmap, &hfpll_config);
+	clk_alpha_pll_configure(&perfcl_pll, regmap, &hfpll_config);
+	clk_alpha_pll_configure(&pwrcl_alt_pll, regmap, &altpll_config);
+	clk_alpha_pll_configure(&perfcl_alt_pll, regmap, &altpll_config);
+
+	/* Wait for PLL(s) to lock */
+	udelay(50);
+
+	/* Enable auto clock selection for both clusters */
+	regmap_update_bits(regmap, PWRCL_REG_OFFSET + CLK_CTL_OFFSET,
+			   CLK_CTL_AUTO_CLK_SEL, CLK_CTL_AUTO_CLK_SEL);
+	regmap_update_bits(regmap, PERFCL_REG_OFFSET + CLK_CTL_OFFSET,
+			   CLK_CTL_AUTO_CLK_SEL, CLK_CTL_AUTO_CLK_SEL);
+
+	/* Ensure write goes through before muxes are switched */
+	udelay(5);
+
+	qcom_cpu_clk_msm8996_acd_init(regmap);
+
+	/* Pulse swallower and soft-start settings */
+	regmap_write(regmap, PWRCL_REG_OFFSET + PSCTL_OFFSET, 0x00030005);
+	regmap_write(regmap, PERFCL_REG_OFFSET + PSCTL_OFFSET, 0x00030005);
+
+	/* Switch clusters to use the ACD leg */
+	regmap_write(regmap, PWRCL_REG_OFFSET + MUX_OFFSET, 0x32);
+	regmap_write(regmap, PERFCL_REG_OFFSET + MUX_OFFSET, 0x32);
+
+	for (i = 0; i < ARRAY_SIZE(cpu_msm8996_hw_clks); i++) {
+		ret = devm_clk_hw_register(dev, cpu_msm8996_hw_clks[i]);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(cpu_msm8996_clks); i++) {
+		ret = devm_clk_register_regmap(dev, cpu_msm8996_clks[i]);
+		if (ret)
+			return ret;
+	}
+
+	/* Enable alt PLLs */
+	clk_prepare_enable(pwrcl_alt_pll.clkr.hw.clk);
+	clk_prepare_enable(perfcl_alt_pll.clkr.hw.clk);
+
+	devm_clk_notifier_register(dev, pwrcl_pmux.clkr.hw.clk, &pwrcl_pmux.nb);
+	devm_clk_notifier_register(dev, perfcl_pmux.clkr.hw.clk, &perfcl_pmux.nb);
+
+	return ret;
+}
+
+#define CPU_CLUSTER_AFFINITY_MASK 0xf00
+#define PWRCL_AFFINITY_MASK 0x000
+#define PERFCL_AFFINITY_MASK 0x100
+
+#define L2ACDCR_REG 0x580ULL
+#define L2ACDTD_REG 0x581ULL
+#define L2ACDDVMRC_REG 0x584ULL
+#define L2ACDSSCR_REG 0x589ULL
+
+static DEFINE_SPINLOCK(qcom_clk_acd_lock);
+
+static void qcom_cpu_clk_msm8996_acd_init(struct regmap *regmap)
+{
+	u64 hwid;
+	u32 val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&qcom_clk_acd_lock, flags);
+
+	val = kryo_l2_get_indirect_reg(L2ACDTD_REG);
+	if (val == 0x00006a11)
+		goto out;
+
+	kryo_l2_set_indirect_reg(L2ACDTD_REG, 0x00006a11);
+	kryo_l2_set_indirect_reg(L2ACDDVMRC_REG, 0x000e0f0f);
+	kryo_l2_set_indirect_reg(L2ACDSSCR_REG, 0x00000601);
+
+	kryo_l2_set_indirect_reg(L2ACDCR_REG, 0x002c5ffd);
+
+	hwid = read_cpuid_mpidr();
+	if ((hwid & CPU_CLUSTER_AFFINITY_MASK) == PWRCL_AFFINITY_MASK)
+		regmap_write(regmap, PWRCL_REG_OFFSET + SSSCTL_OFFSET, 0xf);
+	else
+		regmap_write(regmap, PERFCL_REG_OFFSET + SSSCTL_OFFSET, 0xf);
+
+out:
+	spin_unlock_irqrestore(&qcom_clk_acd_lock, flags);
+}
+
+static int cpu_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
+			       void *data)
+{
+	struct clk_cpu_8996_pmux *cpuclk = to_clk_cpu_8996_pmux_nb(nb);
+	struct clk_notifier_data *cnd = data;
+
+	switch (event) {
+	case PRE_RATE_CHANGE:
+		qcom_cpu_clk_msm8996_acd_init(cpuclk->clkr.regmap);
+
+		/*
+		 * Avoid overvolting. clk_core_set_rate_nolock() walks from top
+		 * to bottom, so it will change the rate of the PLL before
+		 * chaging the parent of PMUX. This can result in pmux getting
+		 * clocked twice the expected rate.
+		 *
+		 * Manually switch to PLL/2 here.
+		 */
+		if (cnd->new_rate < DIV_2_THRESHOLD &&
+		    cnd->old_rate > DIV_2_THRESHOLD)
+			clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, SMUX_INDEX);
+
+		break;
+	case ABORT_RATE_CHANGE:
+		/* Revert manual change */
+		if (cnd->new_rate < DIV_2_THRESHOLD &&
+		    cnd->old_rate > DIV_2_THRESHOLD)
+			clk_cpu_8996_pmux_set_parent(&cpuclk->clkr.hw, ACD_INDEX);
+		break;
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+};
+
+static int qcom_cpu_clk_msm8996_driver_probe(struct platform_device *pdev)
+{
+	static void __iomem *base;
+	struct regmap *regmap;
+	struct clk_hw_onecell_data *data;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	data = devm_kzalloc(dev, struct_size(data, hws, 2), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+	data->num = 2;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(dev, base, &cpu_msm8996_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ret = qcom_cpu_clk_msm8996_register_clks(dev, regmap);
+	if (ret)
+		return ret;
+
+	data->hws[0] = &pwrcl_pmux.clkr.hw;
+	data->hws[1] = &perfcl_pmux.clkr.hw;
+
+	return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, data);
+}
+
+static const struct of_device_id qcom_cpu_clk_msm8996_match_table[] = {
+	{ .compatible = "qcom,msm8996-apcc" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_cpu_clk_msm8996_match_table);
+
+static struct platform_driver qcom_cpu_clk_msm8996_driver = {
+	.probe = qcom_cpu_clk_msm8996_driver_probe,
+	.driver = {
+		.name = "qcom-msm8996-apcc",
+		.of_match_table = qcom_cpu_clk_msm8996_match_table,
+	},
+};
+module_platform_driver(qcom_cpu_clk_msm8996_driver);
+
+MODULE_DESCRIPTION("QCOM MSM8996 CPU Clock Driver");
+MODULE_LICENSE("GPL v2");