clk: Add RISC-V Canaan Kendryte K210 clock driver

Add a clock provider driver for the Canaan Kendryte K210 RISC-V SoC.
This new driver with the compatible string "canaan,k210-clk" implements
support for the full clock structure of the K210 SoC. Since it is
required for the correct operation of the SoC, this driver is
selected by default for compilation when the SOC_CANAAN option is
selected.

With this change, the k210-sysctl driver is turned into a simple
platform driver which enables its power bus clock and triggers
populating its child nodes. The sysctl driver retains the SOC early
initialization code, but the implementation now relies on the new
function k210_clk_early_init() provided by the new clk-k210 driver.

The clock structure implemented and many of the coding ideas for the
driver come from the work by Sean Anderson on the K210 support for the
U-Boot project.

Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: linux-clk@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

1 files changed, 1007 insertions, 0 deletions

diff --git a/drivers/clk/clk-k210.c b/drivers/clk/clk-k210.c
new file mode 100644
index 000000000000..6c84abf5b2e3
--- /dev/null
+++ b/drivers/clk/clk-k210.c
@@ -0,0 +1,1007 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ */
+#define pr_fmt(fmt)     "k210-clk: " fmt
+
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_clk.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/clk-provider.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <soc/canaan/k210-sysctl.h>
+
+#include <dt-bindings/clock/k210-clk.h>
+
+struct k210_sysclk;
+
+struct k210_clk {
+	int id;
+	struct k210_sysclk *ksc;
+	struct clk_hw hw;
+};
+
+struct k210_clk_cfg {
+	const char *name;
+	u8 gate_reg;
+	u8 gate_bit;
+	u8 div_reg;
+	u8 div_shift;
+	u8 div_width;
+	u8 div_type;
+	u8 mux_reg;
+	u8 mux_bit;
+};
+
+enum k210_clk_div_type {
+	K210_DIV_NONE,
+	K210_DIV_ONE_BASED,
+	K210_DIV_DOUBLE_ONE_BASED,
+	K210_DIV_POWER_OF_TWO,
+};
+
+#define K210_GATE(_reg, _bit)	\
+	.gate_reg = (_reg),	\
+	.gate_bit = (_bit)
+
+#define K210_DIV(_reg, _shift, _width, _type)	\
+	.div_reg = (_reg),			\
+	.div_shift = (_shift),			\
+	.div_width = (_width),			\
+	.div_type = (_type)
+
+#define K210_MUX(_reg, _bit)	\
+	.mux_reg = (_reg),	\
+	.mux_bit = (_bit)
+
+static struct k210_clk_cfg k210_clk_cfgs[K210_NUM_CLKS] = {
+	/* Gated clocks, no mux, no divider */
+	[K210_CLK_CPU] = {
+		.name = "cpu",
+		K210_GATE(K210_SYSCTL_EN_CENT, 0)
+	},
+	[K210_CLK_DMA] = {
+		.name = "dma",
+		K210_GATE(K210_SYSCTL_EN_PERI, 1)
+	},
+	[K210_CLK_FFT] = {
+		.name = "fft",
+		K210_GATE(K210_SYSCTL_EN_PERI, 4)
+	},
+	[K210_CLK_GPIO] = {
+		.name = "gpio",
+		K210_GATE(K210_SYSCTL_EN_PERI, 5)
+	},
+	[K210_CLK_UART1] = {
+		.name = "uart1",
+		K210_GATE(K210_SYSCTL_EN_PERI, 16)
+	},
+	[K210_CLK_UART2] = {
+		.name = "uart2",
+		K210_GATE(K210_SYSCTL_EN_PERI, 17)
+	},
+	[K210_CLK_UART3] = {
+		.name = "uart3",
+		K210_GATE(K210_SYSCTL_EN_PERI, 18)
+	},
+	[K210_CLK_FPIOA] = {
+		.name = "fpioa",
+		K210_GATE(K210_SYSCTL_EN_PERI, 20)
+	},
+	[K210_CLK_SHA] = {
+		.name = "sha",
+		K210_GATE(K210_SYSCTL_EN_PERI, 26)
+	},
+	[K210_CLK_AES] = {
+		.name = "aes",
+		K210_GATE(K210_SYSCTL_EN_PERI, 19)
+	},
+	[K210_CLK_OTP] = {
+		.name = "otp",
+		K210_GATE(K210_SYSCTL_EN_PERI, 27)
+	},
+	[K210_CLK_RTC] = {
+		.name = "rtc",
+		K210_GATE(K210_SYSCTL_EN_PERI, 29)
+	},
+
+	/* Gated divider clocks */
+	[K210_CLK_SRAM0] = {
+		.name = "sram0",
+		K210_GATE(K210_SYSCTL_EN_CENT, 1),
+		K210_DIV(K210_SYSCTL_THR0, 0, 4, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_SRAM1] = {
+		.name = "sram1",
+		K210_GATE(K210_SYSCTL_EN_CENT, 2),
+		K210_DIV(K210_SYSCTL_THR0, 4, 4, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_ROM] = {
+		.name = "rom",
+		K210_GATE(K210_SYSCTL_EN_PERI, 0),
+		K210_DIV(K210_SYSCTL_THR0, 16, 4, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_DVP] = {
+		.name = "dvp",
+		K210_GATE(K210_SYSCTL_EN_PERI, 3),
+		K210_DIV(K210_SYSCTL_THR0, 12, 4, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_APB0] = {
+		.name = "apb0",
+		K210_GATE(K210_SYSCTL_EN_CENT, 3),
+		K210_DIV(K210_SYSCTL_SEL0, 3, 3, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_APB1] = {
+		.name = "apb1",
+		K210_GATE(K210_SYSCTL_EN_CENT, 4),
+		K210_DIV(K210_SYSCTL_SEL0, 6, 3, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_APB2] = {
+		.name = "apb2",
+		K210_GATE(K210_SYSCTL_EN_CENT, 5),
+		K210_DIV(K210_SYSCTL_SEL0, 9, 3, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_AI] = {
+		.name = "ai",
+		K210_GATE(K210_SYSCTL_EN_PERI, 2),
+		K210_DIV(K210_SYSCTL_THR0, 8, 4, K210_DIV_ONE_BASED)
+	},
+	[K210_CLK_SPI0] = {
+		.name = "spi0",
+		K210_GATE(K210_SYSCTL_EN_PERI, 6),
+		K210_DIV(K210_SYSCTL_THR1, 0, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_SPI1] = {
+		.name = "spi1",
+		K210_GATE(K210_SYSCTL_EN_PERI, 7),
+		K210_DIV(K210_SYSCTL_THR1, 8, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_SPI2] = {
+		.name = "spi2",
+		K210_GATE(K210_SYSCTL_EN_PERI, 8),
+		K210_DIV(K210_SYSCTL_THR1, 16, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2C0] = {
+		.name = "i2c0",
+		K210_GATE(K210_SYSCTL_EN_PERI, 13),
+		K210_DIV(K210_SYSCTL_THR5, 8, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2C1] = {
+		.name = "i2c1",
+		K210_GATE(K210_SYSCTL_EN_PERI, 14),
+		K210_DIV(K210_SYSCTL_THR5, 16, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2C2] = {
+		.name = "i2c2",
+		K210_GATE(K210_SYSCTL_EN_PERI, 15),
+		K210_DIV(K210_SYSCTL_THR5, 24, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_WDT0] = {
+		.name = "wdt0",
+		K210_GATE(K210_SYSCTL_EN_PERI, 24),
+		K210_DIV(K210_SYSCTL_THR6, 0, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_WDT1] = {
+		.name = "wdt1",
+		K210_GATE(K210_SYSCTL_EN_PERI, 25),
+		K210_DIV(K210_SYSCTL_THR6, 8, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2S0] = {
+		.name = "i2s0",
+		K210_GATE(K210_SYSCTL_EN_PERI, 10),
+		K210_DIV(K210_SYSCTL_THR3, 0, 16, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2S1] = {
+		.name = "i2s1",
+		K210_GATE(K210_SYSCTL_EN_PERI, 11),
+		K210_DIV(K210_SYSCTL_THR3, 16, 16, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2S2] = {
+		.name = "i2s2",
+		K210_GATE(K210_SYSCTL_EN_PERI, 12),
+		K210_DIV(K210_SYSCTL_THR4, 0, 16, K210_DIV_DOUBLE_ONE_BASED)
+	},
+
+	/* Divider clocks, no gate, no mux */
+	[K210_CLK_I2S0_M] = {
+		.name = "i2s0_m",
+		K210_DIV(K210_SYSCTL_THR4, 16, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2S1_M] = {
+		.name = "i2s1_m",
+		K210_DIV(K210_SYSCTL_THR4, 24, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+	[K210_CLK_I2S2_M] = {
+		.name = "i2s2_m",
+		K210_DIV(K210_SYSCTL_THR4, 0, 8, K210_DIV_DOUBLE_ONE_BASED)
+	},
+
+	/* Muxed gated divider clocks */
+	[K210_CLK_SPI3] = {
+		.name = "spi3",
+		K210_GATE(K210_SYSCTL_EN_PERI, 9),
+		K210_DIV(K210_SYSCTL_THR1, 24, 8, K210_DIV_DOUBLE_ONE_BASED),
+		K210_MUX(K210_SYSCTL_SEL0, 12)
+	},
+	[K210_CLK_TIMER0] = {
+		.name = "timer0",
+		K210_GATE(K210_SYSCTL_EN_PERI, 21),
+		K210_DIV(K210_SYSCTL_THR2,  0, 8, K210_DIV_DOUBLE_ONE_BASED),
+		K210_MUX(K210_SYSCTL_SEL0, 13)
+	},
+	[K210_CLK_TIMER1] = {
+		.name = "timer1",
+		K210_GATE(K210_SYSCTL_EN_PERI, 22),
+		K210_DIV(K210_SYSCTL_THR2, 8, 8, K210_DIV_DOUBLE_ONE_BASED),
+		K210_MUX(K210_SYSCTL_SEL0, 14)
+	},
+	[K210_CLK_TIMER2] = {
+		.name = "timer2",
+		K210_GATE(K210_SYSCTL_EN_PERI, 23),
+		K210_DIV(K210_SYSCTL_THR2, 16, 8, K210_DIV_DOUBLE_ONE_BASED),
+		K210_MUX(K210_SYSCTL_SEL0, 15)
+	},
+};
+
+/*
+ * PLL control register bits.
+ */
+#define K210_PLL_CLKR		GENMASK(3, 0)
+#define K210_PLL_CLKF		GENMASK(9, 4)
+#define K210_PLL_CLKOD		GENMASK(13, 10)
+#define K210_PLL_BWADJ		GENMASK(19, 14)
+#define K210_PLL_RESET		(1 << 20)
+#define K210_PLL_PWRD		(1 << 21)
+#define K210_PLL_INTFB		(1 << 22)
+#define K210_PLL_BYPASS		(1 << 23)
+#define K210_PLL_TEST		(1 << 24)
+#define K210_PLL_EN		(1 << 25)
+#define K210_PLL_SEL		GENMASK(27, 26) /* PLL2 only */
+
+/*
+ * PLL lock register bits.
+ */
+#define K210_PLL_LOCK		0
+#define K210_PLL_CLEAR_SLIP	2
+#define K210_PLL_TEST_OUT	3
+
+/*
+ * Clock selector register bits.
+ */
+#define K210_ACLK_SEL		BIT(0)
+#define K210_ACLK_DIV		GENMASK(2, 1)
+
+/*
+ * PLLs.
+ */
+enum k210_pll_id {
+	K210_PLL0, K210_PLL1, K210_PLL2, K210_PLL_NUM
+};
+
+struct k210_pll {
+	enum k210_pll_id id;
+	struct k210_sysclk *ksc;
+	void __iomem *base;
+	void __iomem *reg;
+	void __iomem *lock;
+	u8 lock_shift;
+	u8 lock_width;
+	struct clk_hw hw;
+};
+#define to_k210_pll(_hw)	container_of(_hw, struct k210_pll, hw)
+
+/*
+ * PLLs configuration: by default PLL0 runs at 780 MHz and PLL1 at 299 MHz.
+ * The first 2 SRAM banks depend on ACLK/CPU clock which is by default PLL0
+ * rate divided by 2. Set PLL1 to 390 MHz so that the third SRAM bank has the
+ * same clock as the first 2.
+ */
+struct k210_pll_cfg {
+	u32 reg;
+	u8 lock_shift;
+	u8 lock_width;
+	u32 r;
+	u32 f;
+	u32 od;
+	u32 bwadj;
+};
+
+static struct k210_pll_cfg k210_plls_cfg[] = {
+	{ K210_SYSCTL_PLL0,  0, 2, 0, 59, 1, 59 }, /* 780 MHz */
+	{ K210_SYSCTL_PLL1,  8, 1, 0, 59, 3, 59 }, /* 390 MHz */
+	{ K210_SYSCTL_PLL2, 16, 1, 0, 22, 1, 22 }, /* 299 MHz */
+};
+
+/**
+ * struct k210_sysclk - sysclk driver data
+ * @regs: system controller registers start address
+ * @clk_lock: clock setting spinlock
+ * @plls: SoC PLLs descriptors
+ * @aclk: ACLK clock
+ * @clks: All other clocks
+ */
+struct k210_sysclk {
+	void __iomem			*regs;
+	spinlock_t			clk_lock;
+	struct k210_pll			plls[K210_PLL_NUM];
+	struct clk_hw			aclk;
+	struct k210_clk			clks[K210_NUM_CLKS];
+};
+
+#define to_k210_sysclk(_hw)	container_of(_hw, struct k210_sysclk, aclk)
+
+/*
+ * Set ACLK parent selector: 0 for IN0, 1 for PLL0.
+ */
+static void k210_aclk_set_selector(void __iomem *regs, u8 sel)
+{
+	u32 reg = readl(regs + K210_SYSCTL_SEL0);
+
+	if (sel)
+		reg |= K210_ACLK_SEL;
+	else
+		reg &= K210_ACLK_SEL;
+	writel(reg, regs + K210_SYSCTL_SEL0);
+}
+
+static void k210_init_pll(void __iomem *regs, enum k210_pll_id pllid,
+			  struct k210_pll *pll)
+{
+	pll->id = pllid;
+	pll->reg = regs + k210_plls_cfg[pllid].reg;
+	pll->lock = regs + K210_SYSCTL_PLL_LOCK;
+	pll->lock_shift = k210_plls_cfg[pllid].lock_shift;
+	pll->lock_width = k210_plls_cfg[pllid].lock_width;
+}
+
+static void k210_pll_wait_for_lock(struct k210_pll *pll)
+{
+	u32 reg, mask = GENMASK(pll->lock_shift + pll->lock_width - 1,
+				pll->lock_shift);
+
+	while (true) {
+		reg = readl(pll->lock);
+		if ((reg & mask) == mask)
+			break;
+
+		reg |= BIT(pll->lock_shift + K210_PLL_CLEAR_SLIP);
+		writel(reg, pll->lock);
+	}
+}
+
+static bool k210_pll_hw_is_enabled(struct k210_pll *pll)
+{
+	u32 reg = readl(pll->reg);
+	u32 mask = K210_PLL_PWRD | K210_PLL_EN;
+
+	if (reg & K210_PLL_RESET)
+		return false;
+
+	return (reg & mask) == mask;
+}
+
+static void k210_pll_enable_hw(void __iomem *regs, struct k210_pll *pll)
+{
+	struct k210_pll_cfg *pll_cfg = &k210_plls_cfg[pll->id];
+	u32 reg;
+
+	if (k210_pll_hw_is_enabled(pll))
+		return;
+
+	/*
+	 * For PLL0, we need to re-parent ACLK to IN0 to keep the CPU cores and
+	 * SRAM running.
+	 */
+	if (pll->id == K210_PLL0)
+		k210_aclk_set_selector(regs, 0);
+
+	/* Set PLL factors */
+	reg = readl(pll->reg);
+	reg &= ~GENMASK(19, 0);
+	reg |= FIELD_PREP(K210_PLL_CLKR, pll_cfg->r);
+	reg |= FIELD_PREP(K210_PLL_CLKF, pll_cfg->f);
+	reg |= FIELD_PREP(K210_PLL_CLKOD, pll_cfg->od);
+	reg |= FIELD_PREP(K210_PLL_BWADJ, pll_cfg->bwadj);
+	reg |= K210_PLL_PWRD;
+	writel(reg, pll->reg);
+
+	/*
+	 * Reset the PLL: ensure reset is low before asserting it.
+	 * The magic NOPs come from the Kendryte reference SDK.
+	 */
+	reg &= ~K210_PLL_RESET;
+	writel(reg, pll->reg);
+	reg |= K210_PLL_RESET;
+	writel(reg, pll->reg);
+	nop();
+	nop();
+	reg &= ~K210_PLL_RESET;
+	writel(reg, pll->reg);
+
+	k210_pll_wait_for_lock(pll);
+
+	reg &= ~K210_PLL_BYPASS;
+	reg |= K210_PLL_EN;
+	writel(reg, pll->reg);
+
+	if (pll->id == K210_PLL0)
+		k210_aclk_set_selector(regs, 1);
+}
+
+static int k210_pll_enable(struct clk_hw *hw)
+{
+	struct k210_pll *pll = to_k210_pll(hw);
+	struct k210_sysclk *ksc = pll->ksc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+
+	k210_pll_enable_hw(ksc->regs, pll);
+
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+
+	return 0;
+}
+
+static void k210_pll_disable(struct clk_hw *hw)
+{
+	struct k210_pll *pll = to_k210_pll(hw);
+	struct k210_sysclk *ksc = pll->ksc;
+	unsigned long flags;
+	u32 reg;
+
+	/*
+	 * Bypassing before powering off is important so child clocks do not
+	 * stop working. This is especially important for pll0, the indirect
+	 * parent of the cpu clock.
+	 */
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+	reg = readl(pll->reg);
+	reg |= K210_PLL_BYPASS;
+	writel(reg, pll->reg);
+
+	reg &= ~K210_PLL_PWRD;
+	reg &= ~K210_PLL_EN;
+	writel(reg, pll->reg);
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+}
+
+static int k210_pll_is_enabled(struct clk_hw *hw)
+{
+	return k210_pll_hw_is_enabled(to_k210_pll(hw));
+}
+
+static unsigned long k210_pll_get_rate(struct clk_hw *hw,
+				       unsigned long parent_rate)
+{
+	struct k210_pll *pll = to_k210_pll(hw);
+	u32 reg = readl(pll->reg);
+	u32 r, f, od;
+
+	if (reg & K210_PLL_BYPASS)
+		return parent_rate;
+
+	if (!(reg & K210_PLL_PWRD))
+		return 0;
+
+	r = FIELD_GET(K210_PLL_CLKR, reg) + 1;
+	f = FIELD_GET(K210_PLL_CLKF, reg) + 1;
+	od = FIELD_GET(K210_PLL_CLKOD, reg) + 1;
+
+	return (u64)parent_rate * f / (r * od);
+}
+
+static const struct clk_ops k210_pll_ops = {
+	.enable		= k210_pll_enable,
+	.disable	= k210_pll_disable,
+	.is_enabled	= k210_pll_is_enabled,
+	.recalc_rate	= k210_pll_get_rate,
+};
+
+static int k210_pll2_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct k210_pll *pll = to_k210_pll(hw);
+	struct k210_sysclk *ksc = pll->ksc;
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+
+	reg = readl(pll->reg);
+	reg &= ~K210_PLL_SEL;
+	reg |= FIELD_PREP(K210_PLL_SEL, index);
+	writel(reg, pll->reg);
+
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+
+	return 0;
+}
+
+static u8 k210_pll2_get_parent(struct clk_hw *hw)
+{
+	struct k210_pll *pll = to_k210_pll(hw);
+	u32 reg = readl(pll->reg);
+
+	return FIELD_GET(K210_PLL_SEL, reg);
+}
+
+static const struct clk_ops k210_pll2_ops = {
+	.enable		= k210_pll_enable,
+	.disable	= k210_pll_disable,
+	.is_enabled	= k210_pll_is_enabled,
+	.recalc_rate	= k210_pll_get_rate,
+	.set_parent	= k210_pll2_set_parent,
+	.get_parent	= k210_pll2_get_parent,
+};
+
+static int __init k210_register_pll(struct device_node *np,
+				    struct k210_sysclk *ksc,
+				    enum k210_pll_id pllid, const char *name,
+				    int num_parents, const struct clk_ops *ops)
+{
+	struct k210_pll *pll = &ksc->plls[pllid];
+	struct clk_init_data init = {};
+	const struct clk_parent_data parent_data[] = {
+		{ /* .index = 0 for in0 */ },
+		{ .hw = &ksc->plls[K210_PLL0].hw },
+		{ .hw = &ksc->plls[K210_PLL1].hw },
+	};
+
+	init.name = name;
+	init.parent_data = parent_data;
+	init.num_parents = num_parents;
+	init.ops = ops;
+
+	pll->hw.init = &init;
+	pll->ksc = ksc;
+
+	return of_clk_hw_register(np, &pll->hw);
+}
+
+static int __init k210_register_plls(struct device_node *np,
+				     struct k210_sysclk *ksc)
+{
+	int i, ret;
+
+	for (i = 0; i < K210_PLL_NUM; i++)
+		k210_init_pll(ksc->regs, i, &ksc->plls[i]);
+
+	/* PLL0 and PLL1 only have IN0 as parent */
+	ret = k210_register_pll(np, ksc, K210_PLL0, "pll0", 1, &k210_pll_ops);
+	if (ret) {
+		pr_err("%pOFP: register PLL0 failed\n", np);
+		return ret;
+	}
+	ret = k210_register_pll(np, ksc, K210_PLL1, "pll1", 1, &k210_pll_ops);
+	if (ret) {
+		pr_err("%pOFP: register PLL1 failed\n", np);
+		return ret;
+	}
+
+	/* PLL2 has IN0, PLL0 and PLL1 as parents */
+	ret = k210_register_pll(np, ksc, K210_PLL2, "pll2", 3, &k210_pll2_ops);
+	if (ret) {
+		pr_err("%pOFP: register PLL2 failed\n", np);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int k210_aclk_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct k210_sysclk *ksc = to_k210_sysclk(hw);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+
+	k210_aclk_set_selector(ksc->regs, index);
+
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+
+	return 0;
+}
+
+static u8 k210_aclk_get_parent(struct clk_hw *hw)
+{
+	struct k210_sysclk *ksc = to_k210_sysclk(hw);
+	u32 sel;
+
+	sel = readl(ksc->regs + K210_SYSCTL_SEL0) & K210_ACLK_SEL;
+
+	return sel ? 1 : 0;
+}
+
+static unsigned long k210_aclk_get_rate(struct clk_hw *hw,
+					unsigned long parent_rate)
+{
+	struct k210_sysclk *ksc = to_k210_sysclk(hw);
+	u32 reg = readl(ksc->regs + K210_SYSCTL_SEL0);
+	unsigned int shift;
+
+	if (!(reg & 0x1))
+		return parent_rate;
+
+	shift = FIELD_GET(K210_ACLK_DIV, reg);
+
+	return parent_rate / (2UL << shift);
+}
+
+static const struct clk_ops k210_aclk_ops = {
+	.set_parent	= k210_aclk_set_parent,
+	.get_parent	= k210_aclk_get_parent,
+	.recalc_rate	= k210_aclk_get_rate,
+};
+
+/*
+ * ACLK has IN0 and PLL0 as parents.
+ */
+static int __init k210_register_aclk(struct device_node *np,
+				     struct k210_sysclk *ksc)
+{
+	struct clk_init_data init = {};
+	const struct clk_parent_data parent_data[] = {
+		{ /* .index = 0 for in0 */ },
+		{ .hw = &ksc->plls[K210_PLL0].hw },
+	};
+	int ret;
+
+	init.name = "aclk";
+	init.parent_data = parent_data;
+	init.num_parents = 2;
+	init.ops = &k210_aclk_ops;
+	ksc->aclk.init = &init;
+
+	ret = of_clk_hw_register(np, &ksc->aclk);
+	if (ret) {
+		pr_err("%pOFP: register aclk failed\n", np);
+		return ret;
+	}
+
+	return 0;
+}
+
+#define to_k210_clk(_hw)	container_of(_hw, struct k210_clk, hw)
+
+static int k210_clk_enable(struct clk_hw *hw)
+{
+	struct k210_clk *kclk = to_k210_clk(hw);
+	struct k210_sysclk *ksc = kclk->ksc;
+	struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
+	unsigned long flags;
+	u32 reg;
+
+	if (!cfg->gate_reg)
+		return 0;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+	reg = readl(ksc->regs + cfg->gate_reg);
+	reg |= BIT(cfg->gate_bit);
+	writel(reg, ksc->regs + cfg->gate_reg);
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+
+	return 0;
+}
+
+static void k210_clk_disable(struct clk_hw *hw)
+{
+	struct k210_clk *kclk = to_k210_clk(hw);
+	struct k210_sysclk *ksc = kclk->ksc;
+	struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
+	unsigned long flags;
+	u32 reg;
+
+	if (!cfg->gate_reg)
+		return;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+	reg = readl(ksc->regs + cfg->gate_reg);
+	reg &= ~BIT(cfg->gate_bit);
+	writel(reg, ksc->regs + cfg->gate_reg);
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+}
+
+static int k210_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct k210_clk *kclk = to_k210_clk(hw);
+	struct k210_sysclk *ksc = kclk->ksc;
+	struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
+	unsigned long flags;
+	u32 reg;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+	reg = readl(ksc->regs + cfg->mux_reg);
+	if (index)
+		reg |= BIT(cfg->mux_bit);
+	else
+		reg &= ~BIT(cfg->mux_bit);
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+
+	return 0;
+}
+
+static u8 k210_clk_get_parent(struct clk_hw *hw)
+{
+	struct k210_clk *kclk = to_k210_clk(hw);
+	struct k210_sysclk *ksc = kclk->ksc;
+	struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
+	unsigned long flags;
+	u32 reg, idx;
+
+	spin_lock_irqsave(&ksc->clk_lock, flags);
+	reg = readl(ksc->regs + cfg->mux_reg);
+	idx = (reg & BIT(cfg->mux_bit)) ? 1 : 0;
+	spin_unlock_irqrestore(&ksc->clk_lock, flags);
+
+	return idx;
+}
+
+static unsigned long k210_clk_get_rate(struct clk_hw *hw,
+				       unsigned long parent_rate)
+{
+	struct k210_clk *kclk = to_k210_clk(hw);
+	struct k210_sysclk *ksc = kclk->ksc;
+	struct k210_clk_cfg *cfg = &k210_clk_cfgs[kclk->id];
+	u32 reg, div_val;
+
+	if (!cfg->div_reg)
+		return parent_rate;
+
+	reg = readl(ksc->regs + cfg->div_reg);
+	div_val = (reg >> cfg->div_shift) & GENMASK(cfg->div_width - 1, 0);
+
+	switch (cfg->div_type) {
+	case K210_DIV_ONE_BASED:
+		return parent_rate / (div_val + 1);
+	case K210_DIV_DOUBLE_ONE_BASED:
+		return parent_rate / ((div_val + 1) * 2);
+	case K210_DIV_POWER_OF_TWO:
+		return parent_rate / (2UL << div_val);
+	case K210_DIV_NONE:
+	default:
+		return 0;
+	}
+}
+
+static const struct clk_ops k210_clk_mux_ops = {
+	.enable		= k210_clk_enable,
+	.disable	= k210_clk_disable,
+	.set_parent	= k210_clk_set_parent,
+	.get_parent	= k210_clk_get_parent,
+	.recalc_rate	= k210_clk_get_rate,
+};
+
+static const struct clk_ops k210_clk_ops = {
+	.enable		= k210_clk_enable,
+	.disable	= k210_clk_disable,
+	.recalc_rate	= k210_clk_get_rate,
+};
+
+static void __init k210_register_clk(struct device_node *np,
+				     struct k210_sysclk *ksc, int id,
+				     const struct clk_parent_data *parent_data,
+				     int num_parents, unsigned long flags)
+{
+	struct k210_clk *kclk = &ksc->clks[id];
+	struct clk_init_data init = {};
+	int ret;
+
+	init.name = k210_clk_cfgs[id].name;
+	init.flags = flags;
+	init.parent_data = parent_data;
+	init.num_parents = num_parents;
+	if (num_parents > 1)
+		init.ops = &k210_clk_mux_ops;
+	else
+		init.ops = &k210_clk_ops;
+
+	kclk->id = id;
+	kclk->ksc = ksc;
+	kclk->hw.init = &init;
+
+	ret = of_clk_hw_register(np, &kclk->hw);
+	if (ret) {
+		pr_err("%pOFP: register clock %s failed\n",
+		       np, k210_clk_cfgs[id].name);
+		kclk->id = -1;
+	}
+}
+
+/*
+ * All muxed clocks have IN0 and PLL0 as parents.
+ */
+static inline void __init k210_register_mux_clk(struct device_node *np,
+						struct k210_sysclk *ksc, int id)
+{
+	const struct clk_parent_data parent_data[2] = {
+		{ /* .index = 0 for in0 */ },
+		{ .hw = &ksc->plls[K210_PLL0].hw }
+	};
+
+	k210_register_clk(np, ksc, id, parent_data, 2, 0);
+}
+
+static inline void __init k210_register_in0_child(struct device_node *np,
+						struct k210_sysclk *ksc, int id)
+{
+	const struct clk_parent_data parent_data = {
+		/* .index = 0 for in0 */
+	};
+
+	k210_register_clk(np, ksc, id, &parent_data, 1, 0);
+}
+
+static inline void __init k210_register_pll_child(struct device_node *np,
+						struct k210_sysclk *ksc, int id,
+						enum k210_pll_id pllid,
+						unsigned long flags)
+{
+	const struct clk_parent_data parent_data = {
+		.hw = &ksc->plls[pllid].hw,
+	};
+
+	k210_register_clk(np, ksc, id, &parent_data, 1, flags);
+}
+
+static inline void __init k210_register_aclk_child(struct device_node *np,
+						struct k210_sysclk *ksc, int id,
+						unsigned long flags)
+{
+	const struct clk_parent_data parent_data = {
+		.hw = &ksc->aclk,
+	};
+
+	k210_register_clk(np, ksc, id, &parent_data, 1, flags);
+}
+
+static inline void __init k210_register_clk_child(struct device_node *np,
+						struct k210_sysclk *ksc, int id,
+						int parent_id)
+{
+	const struct clk_parent_data parent_data = {
+		.hw = &ksc->clks[parent_id].hw,
+	};
+
+	k210_register_clk(np, ksc, id, &parent_data, 1, 0);
+}
+
+static struct clk_hw *k210_clk_hw_onecell_get(struct of_phandle_args *clkspec,
+					      void *data)
+{
+	struct k210_sysclk *ksc = data;
+	unsigned int idx = clkspec->args[0];
+
+	if (idx >= K210_NUM_CLKS)
+		return ERR_PTR(-EINVAL);
+
+	return &ksc->clks[idx].hw;
+}
+
+static void __init k210_clk_init(struct device_node *np)
+{
+	struct device_node *sysctl_np;
+	struct k210_sysclk *ksc;
+	int i, ret;
+
+	ksc = kzalloc(sizeof(*ksc), GFP_KERNEL);
+	if (!ksc)
+		return;
+
+	spin_lock_init(&ksc->clk_lock);
+	sysctl_np = of_get_parent(np);
+	ksc->regs = of_iomap(sysctl_np, 0);
+	of_node_put(sysctl_np);
+	if (!ksc->regs) {
+		pr_err("%pOFP: failed to map registers\n", np);
+		return;
+	}
+
+	ret = k210_register_plls(np, ksc);
+	if (ret)
+		return;
+
+	ret = k210_register_aclk(np, ksc);
+	if (ret)
+		return;
+
+	/*
+	 * Critical clocks: there are no consumers of the SRAM clocks,
+	 * including the AI clock for the third SRAM bank. The CPU clock
+	 * is only referenced by the uarths serial device and so would be
+	 * disabled if the serial console is disabled to switch to another
+	 * console. Mark all these clocks as critical so that they are never
+	 * disabled by the core clock management.
+	 */
+	k210_register_aclk_child(np, ksc, K210_CLK_CPU, CLK_IS_CRITICAL);
+	k210_register_aclk_child(np, ksc, K210_CLK_SRAM0, CLK_IS_CRITICAL);
+	k210_register_aclk_child(np, ksc, K210_CLK_SRAM1, CLK_IS_CRITICAL);
+	k210_register_pll_child(np, ksc, K210_CLK_AI, K210_PLL1,
+				CLK_IS_CRITICAL);
+
+	/* Clocks with aclk as source */
+	k210_register_aclk_child(np, ksc, K210_CLK_DMA, 0);
+	k210_register_aclk_child(np, ksc, K210_CLK_FFT, 0);
+	k210_register_aclk_child(np, ksc, K210_CLK_ROM, 0);
+	k210_register_aclk_child(np, ksc, K210_CLK_DVP, 0);
+	k210_register_aclk_child(np, ksc, K210_CLK_APB0, 0);
+	k210_register_aclk_child(np, ksc, K210_CLK_APB1, 0);
+	k210_register_aclk_child(np, ksc, K210_CLK_APB2, 0);
+
+	/* Clocks with PLL0 as source */
+	k210_register_pll_child(np, ksc, K210_CLK_SPI0, K210_PLL0, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_SPI1, K210_PLL0, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_SPI2, K210_PLL0, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2C0, K210_PLL0, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2C1, K210_PLL0, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2C2, K210_PLL0, 0);
+
+	/* Clocks with PLL2 as source */
+	k210_register_pll_child(np, ksc, K210_CLK_I2S0, K210_PLL2, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2S1, K210_PLL2, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2S2, K210_PLL2, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2S0_M, K210_PLL2, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2S1_M, K210_PLL2, 0);
+	k210_register_pll_child(np, ksc, K210_CLK_I2S2_M, K210_PLL2, 0);
+
+	/* Clocks with IN0 as source */
+	k210_register_in0_child(np, ksc, K210_CLK_WDT0);
+	k210_register_in0_child(np, ksc, K210_CLK_WDT1);
+	k210_register_in0_child(np, ksc, K210_CLK_RTC);
+
+	/* Clocks with APB0 as source */
+	k210_register_clk_child(np, ksc, K210_CLK_GPIO, K210_CLK_APB0);
+	k210_register_clk_child(np, ksc, K210_CLK_UART1, K210_CLK_APB0);
+	k210_register_clk_child(np, ksc, K210_CLK_UART2, K210_CLK_APB0);
+	k210_register_clk_child(np, ksc, K210_CLK_UART3, K210_CLK_APB0);
+	k210_register_clk_child(np, ksc, K210_CLK_FPIOA, K210_CLK_APB0);
+	k210_register_clk_child(np, ksc, K210_CLK_SHA, K210_CLK_APB0);
+
+	/* Clocks with APB1 as source */
+	k210_register_clk_child(np, ksc, K210_CLK_AES, K210_CLK_APB1);
+	k210_register_clk_child(np, ksc, K210_CLK_OTP, K210_CLK_APB1);
+
+	/* Mux clocks with in0 or pll0 as source */
+	k210_register_mux_clk(np, ksc, K210_CLK_SPI3);
+	k210_register_mux_clk(np, ksc, K210_CLK_TIMER0);
+	k210_register_mux_clk(np, ksc, K210_CLK_TIMER1);
+	k210_register_mux_clk(np, ksc, K210_CLK_TIMER2);
+
+	/* Check for registration errors */
+	for (i = 0; i < K210_NUM_CLKS; i++) {
+		if (ksc->clks[i].id != i)
+			return;
+	}
+
+	ret = of_clk_add_hw_provider(np, k210_clk_hw_onecell_get, ksc);
+	if (ret) {
+		pr_err("%pOFP: add clock provider failed %d\n", np, ret);
+		return;
+	}
+
+	pr_info("%pOFP: CPU running at %lu MHz\n",
+		np, clk_hw_get_rate(&ksc->clks[K210_CLK_CPU].hw) / 1000000);
+}
+
+CLK_OF_DECLARE(k210_clk, "canaan,k210-clk", k210_clk_init);
+
+/*
+ * Enable PLL1 to be able to use the AI SRAM.
+ */
+void __init k210_clk_early_init(void __iomem *regs)
+{
+	struct k210_pll pll1;
+
+	/* Make sure ACLK selector is set to PLL0 */
+	k210_aclk_set_selector(regs, 1);
+
+	/* Startup PLL1 to enable the aisram bank for general memory use */
+	k210_init_pll(regs, K210_PLL1, &pll1);
+	k210_pll_enable_hw(regs, &pll1);
+}