clk: mtmips: add clock driver for MediaTek MT7621 SoC

This patch adds a clock driver for MediaTek MT7621 SoC.
This driver provides clock gate control as well as getting clock frequency
for CPU/SYS/XTAL and some peripherals.

Reviewed-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

2 files changed, 289 insertions, 0 deletions

diff --git a/drivers/clk/mtmips/Makefile b/drivers/clk/mtmips/Makefile
index 732e7f2..ee8b5af 100644
--- a/drivers/clk/mtmips/Makefile
+++ b/drivers/clk/mtmips/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_SOC_MT7620) += clk-mt7620.o
+obj-$(CONFIG_SOC_MT7621) += clk-mt7621.o
 obj-$(CONFIG_SOC_MT7628) += clk-mt7628.o
diff --git a/drivers/clk/mtmips/clk-mt7621.c b/drivers/clk/mtmips/clk-mt7621.c
new file mode 100644
index 0000000..03363b7
--- /dev/null
+++ b/drivers/clk/mtmips/clk-mt7621.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 MediaTek Inc. All rights reserved.
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <clk-uclass.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <dt-bindings/clock/mt7621-clk.h>
+#include <linux/io.h>
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+
+#define SYSC_MAP_SIZE			0x100
+#define MEMC_MAP_SIZE			0x1000
+
+/* SYSC */
+#define SYSCFG0_REG			0x10
+#define XTAL_MODE_SEL			GENMASK(8, 6)
+
+#define CLKCFG0_REG			0x2c
+#define CPU_CLK_SEL			GENMASK(31, 30)
+#define PERI_CLK_SEL			BIT(4)
+
+#define CLKCFG1_REG			0x30
+
+#define CUR_CLK_STS_REG			0x44
+#define CUR_CPU_FDIV			GENMASK(12, 8)
+#define CUR_CPU_FFRAC			GENMASK(4, 0)
+
+/* MEMC */
+#define MEMPLL1_REG			0x0604
+#define RG_MEPL_DIV2_SEL		GENMASK(2, 1)
+
+#define MEMPLL6_REG			0x0618
+#define MEMPLL18_REG			0x0648
+#define RG_MEPL_PREDIV			GENMASK(13, 12)
+#define RG_MEPL_FBDIV			GENMASK(10, 4)
+
+/* Fixed 500M clock */
+#define GMPLL_CLK			500000000
+
+struct mt7621_clk_priv {
+	void __iomem *sysc_base;
+	int cpu_clk;
+	int ddr_clk;
+	int sys_clk;
+	int xtal_clk;
+};
+
+enum mt7621_clk_src {
+	CLK_SRC_CPU,
+	CLK_SRC_DDR,
+	CLK_SRC_SYS,
+	CLK_SRC_XTAL,
+	CLK_SRC_PERI,
+	CLK_SRC_125M,
+	CLK_SRC_150M,
+	CLK_SRC_250M,
+	CLK_SRC_270M,
+
+	__CLK_SRC_MAX
+};
+
+struct mt7621_clk_map {
+	u32 cgbit;
+	enum mt7621_clk_src clksrc;
+};
+
+#define CLK_MAP(_id, _cg, _src) \
+	[_id] = { .cgbit = (_cg), .clksrc = (_src) }
+
+#define CLK_MAP_SRC(_id, _src) \
+	[_id] = { .cgbit = UINT32_MAX, .clksrc = (_src) }
+
+static const struct mt7621_clk_map mt7621_clk_mappings[] = {
+	CLK_MAP_SRC(MT7621_CLK_XTAL, CLK_SRC_XTAL),
+	CLK_MAP_SRC(MT7621_CLK_CPU, CLK_SRC_CPU),
+	CLK_MAP_SRC(MT7621_CLK_BUS, CLK_SRC_SYS),
+	CLK_MAP_SRC(MT7621_CLK_50M, CLK_SRC_PERI),
+	CLK_MAP_SRC(MT7621_CLK_125M, CLK_SRC_125M),
+	CLK_MAP_SRC(MT7621_CLK_150M, CLK_SRC_150M),
+	CLK_MAP_SRC(MT7621_CLK_250M, CLK_SRC_250M),
+	CLK_MAP_SRC(MT7621_CLK_270M, CLK_SRC_270M),
+
+	CLK_MAP(MT7621_CLK_HSDMA, 5, CLK_SRC_150M),
+	CLK_MAP(MT7621_CLK_FE, 6, CLK_SRC_250M),
+	CLK_MAP(MT7621_CLK_SP_DIVTX, 7, CLK_SRC_270M),
+	CLK_MAP(MT7621_CLK_TIMER, 8, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_PCM, 11, CLK_SRC_270M),
+	CLK_MAP(MT7621_CLK_PIO, 13, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_GDMA, 14, CLK_SRC_SYS),
+	CLK_MAP(MT7621_CLK_NAND, 15, CLK_SRC_125M),
+	CLK_MAP(MT7621_CLK_I2C, 16, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_I2S, 17, CLK_SRC_270M),
+	CLK_MAP(MT7621_CLK_SPI, 18, CLK_SRC_SYS),
+	CLK_MAP(MT7621_CLK_UART1, 19, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_UART2, 20, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_UART3, 21, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_ETH, 23, CLK_SRC_PERI),
+	CLK_MAP(MT7621_CLK_PCIE0, 24, CLK_SRC_125M),
+	CLK_MAP(MT7621_CLK_PCIE1, 25, CLK_SRC_125M),
+	CLK_MAP(MT7621_CLK_PCIE2, 26, CLK_SRC_125M),
+	CLK_MAP(MT7621_CLK_CRYPTO, 29, CLK_SRC_250M),
+	CLK_MAP(MT7621_CLK_SHXC, 30, CLK_SRC_PERI),
+
+	CLK_MAP_SRC(MT7621_CLK_MAX, __CLK_SRC_MAX),
+
+	CLK_MAP_SRC(MT7621_CLK_DDR, CLK_SRC_DDR),
+};
+
+static ulong mt7621_clk_get_rate(struct clk *clk)
+{
+	struct mt7621_clk_priv *priv = dev_get_priv(clk->dev);
+	u32 val;
+
+	switch (mt7621_clk_mappings[clk->id].clksrc) {
+	case CLK_SRC_CPU:
+		return priv->cpu_clk;
+	case CLK_SRC_DDR:
+		return priv->ddr_clk;
+	case CLK_SRC_SYS:
+		return priv->sys_clk;
+	case CLK_SRC_XTAL:
+		return priv->xtal_clk;
+	case CLK_SRC_PERI:
+		val = readl(priv->sysc_base + CLKCFG0_REG);
+		if (val & PERI_CLK_SEL)
+			return priv->xtal_clk;
+		else
+			return GMPLL_CLK / 10;
+	case CLK_SRC_125M:
+		return 125000000;
+	case CLK_SRC_150M:
+		return 150000000;
+	case CLK_SRC_250M:
+		return 250000000;
+	case CLK_SRC_270M:
+		return 270000000;
+	default:
+		return 0;
+	}
+}
+
+static int mt7621_clk_enable(struct clk *clk)
+{
+	struct mt7621_clk_priv *priv = dev_get_priv(clk->dev);
+	u32 cgbit;
+
+	cgbit = mt7621_clk_mappings[clk->id].cgbit;
+	if (cgbit == UINT32_MAX)
+		return -ENOSYS;
+
+	setbits_32(priv->sysc_base + CLKCFG1_REG, BIT(cgbit));
+
+	return 0;
+}
+
+static int mt7621_clk_disable(struct clk *clk)
+{
+	struct mt7621_clk_priv *priv = dev_get_priv(clk->dev);
+	u32 cgbit;
+
+	cgbit = mt7621_clk_mappings[clk->id].cgbit;
+	if (cgbit == UINT32_MAX)
+		return -ENOSYS;
+
+	clrbits_32(priv->sysc_base + CLKCFG1_REG, BIT(cgbit));
+
+	return 0;
+}
+
+static int mt7621_clk_request(struct clk *clk)
+{
+	if (clk->id >= ARRAY_SIZE(mt7621_clk_mappings))
+		return -EINVAL;
+	return 0;
+}
+
+const struct clk_ops mt7621_clk_ops = {
+	.request = mt7621_clk_request,
+	.enable = mt7621_clk_enable,
+	.disable = mt7621_clk_disable,
+	.get_rate = mt7621_clk_get_rate,
+};
+
+static void mt7621_get_clocks(struct mt7621_clk_priv *priv, struct regmap *memc)
+{
+	u32 bs, xtal_sel, clkcfg0, cur_clk, mempll, dividx, fb;
+	u32 xtal_clk, xtal_div, ffiv, ffrac, cpu_clk, ddr_clk;
+	static const u32 xtal_div_tbl[] = {0, 1, 2, 2};
+
+	bs = readl(priv->sysc_base + SYSCFG0_REG);
+	clkcfg0 = readl(priv->sysc_base + CLKCFG0_REG);
+	cur_clk = readl(priv->sysc_base + CUR_CLK_STS_REG);
+
+	xtal_sel = FIELD_GET(XTAL_MODE_SEL, bs);
+
+	if (xtal_sel <= 2)
+		xtal_clk = 20 * 1000 * 1000;
+	else if (xtal_sel <= 5)
+		xtal_clk = 40 * 1000 * 1000;
+	else
+		xtal_clk = 25 * 1000 * 1000;
+
+	switch (FIELD_GET(CPU_CLK_SEL, clkcfg0)) {
+	case 0:
+		cpu_clk = GMPLL_CLK;
+		break;
+	case 1:
+		regmap_read(memc, MEMPLL18_REG, &mempll);
+		dividx = FIELD_GET(RG_MEPL_PREDIV, mempll);
+		fb = FIELD_GET(RG_MEPL_FBDIV, mempll);
+		xtal_div = 1 << xtal_div_tbl[dividx];
+		cpu_clk = (fb + 1) * xtal_clk / xtal_div;
+		break;
+	default:
+		cpu_clk = xtal_clk;
+	}
+
+	ffiv = FIELD_GET(CUR_CPU_FDIV, cur_clk);
+	ffrac = FIELD_GET(CUR_CPU_FFRAC, cur_clk);
+	cpu_clk = cpu_clk / ffiv * ffrac;
+
+	regmap_read(memc, MEMPLL6_REG, &mempll);
+	dividx = FIELD_GET(RG_MEPL_PREDIV, mempll);
+	fb = FIELD_GET(RG_MEPL_FBDIV, mempll);
+	xtal_div = 1 << xtal_div_tbl[dividx];
+	ddr_clk = fb * xtal_clk / xtal_div;
+
+	regmap_read(memc, MEMPLL1_REG, &bs);
+	if (!FIELD_GET(RG_MEPL_DIV2_SEL, bs))
+		ddr_clk *= 2;
+
+	priv->cpu_clk = cpu_clk;
+	priv->sys_clk = cpu_clk / 4;
+	priv->ddr_clk = ddr_clk;
+	priv->xtal_clk = xtal_clk;
+}
+
+static int mt7621_clk_probe(struct udevice *dev)
+{
+	struct mt7621_clk_priv *priv = dev_get_priv(dev);
+	struct ofnode_phandle_args args;
+	struct udevice *pdev;
+	struct regmap *memc;
+	int ret;
+
+	pdev = dev_get_parent(dev);
+	if (!pdev)
+		return -ENODEV;
+
+	priv->sysc_base = dev_remap_addr(pdev);
+	if (!priv->sysc_base)
+		return -EINVAL;
+
+	/* get corresponding memc phandle */
+	ret = dev_read_phandle_with_args(dev, "mediatek,memc", NULL, 0, 0,
+					 &args);
+	if (ret)
+		return ret;
+
+	memc = syscon_node_to_regmap(args.node);
+	if (IS_ERR(memc))
+		return PTR_ERR(memc);
+
+	mt7621_get_clocks(priv, memc);
+
+	return 0;
+}
+
+static const struct udevice_id mt7621_clk_ids[] = {
+	{ .compatible = "mediatek,mt7621-clk" },
+	{ }
+};
+
+U_BOOT_DRIVER(mt7621_clk) = {
+	.name = "mt7621-clk",
+	.id = UCLASS_CLK,
+	.of_match = mt7621_clk_ids,
+	.probe = mt7621_clk_probe,
+	.priv_auto = sizeof(struct mt7621_clk_priv),
+	.ops = &mt7621_clk_ops,
+};