[PATCH 3/4] clk: add Amlogic meson clock driver

[b.galvani@gmail.com (Beniamino Galvani)]

Introduce a basic clock driver for Amlogic Meson SoCs which supports
enabling/disabling clock gates and getting their frequency.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
---
 arch/arm/mach-meson/Kconfig |   2 +
 drivers/clk/Makefile        |   1 +
 drivers/clk/clk_meson.c     | 196 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 199 insertions(+)
 create mode 100644 drivers/clk/clk_meson.c

diff --git a/arch/arm/mach-meson/Kconfig b/arch/arm/mach-meson/Kconfig
index d4bd230be3..7acee3bc5c 100644
--- a/arch/arm/mach-meson/Kconfig
+++ b/arch/arm/mach-meson/Kconfig
@@ -3,6 +3,7 @@ if ARCH_MESON
 config MESON_GXBB
 	bool "Support Meson GXBaby"
 	select ARM64
+	select CLK
 	select DM
 	select DM_SERIAL
 	help
@@ -12,6 +13,7 @@ config MESON_GXBB
 config MESON_GXL
 	bool "Support Meson GXL"
 	select ARM64
+	select CLK
 	select DM
 	select DM_SERIAL
 	help
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index bcc8f82fb6..67da27873d 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -7,6 +7,7 @@
 
 obj-$(CONFIG_$(SPL_TPL_)CLK) += clk-uclass.o clk_fixed_rate.o
 obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
+obj-$(CONFIG_ARCH_MESON) += clk_meson.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox.o
 obj-$(CONFIG_SANDBOX) += clk_sandbox_test.o
 obj-$(CONFIG_MACH_PIC32) += clk_pic32.o
diff --git a/drivers/clk/clk_meson.c b/drivers/clk/clk_meson.c
new file mode 100644
index 0000000000..3cf9372e05
--- /dev/null
+++ b/drivers/clk/clk_meson.c
@@ -0,0 +1,196 @@
+/*
+ * (C) Copyright 2017 - Beniamino Galvani <b.galvani@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arch/clock.h>
+#include <asm/io.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <dt-bindings/clock/gxbb-clkc.h>
+
+struct meson_clk {
+	void __iomem *addr;
+	ulong rate;
+};
+
+struct meson_gate {
+	unsigned int reg;
+	unsigned int bit;
+};
+
+#define MESON_GATE(id, _reg, _bit)		\
+	[id] = {				\
+		.reg = (_reg),			\
+		.bit = (_bit),			\
+	}
+
+struct meson_gate gates[] = {
+	/* Everything Else (EE) domain gates */
+	MESON_GATE(CLKID_DDR, HHI_GCLK_MPEG0, 0),
+	MESON_GATE(CLKID_DOS, HHI_GCLK_MPEG0, 1),
+	MESON_GATE(CLKID_ISA, HHI_GCLK_MPEG0, 5),
+	MESON_GATE(CLKID_PL301, HHI_GCLK_MPEG0, 6),
+	MESON_GATE(CLKID_PERIPHS, HHI_GCLK_MPEG0, 7),
+	MESON_GATE(CLKID_SPICC, HHI_GCLK_MPEG0, 8),
+	MESON_GATE(CLKID_I2C, HHI_GCLK_MPEG0, 9),
+	MESON_GATE(CLKID_SAR_ADC, HHI_GCLK_MPEG0, 10),
+	MESON_GATE(CLKID_SMART_CARD, HHI_GCLK_MPEG0, 11),
+	MESON_GATE(CLKID_RNG0, HHI_GCLK_MPEG0, 12),
+	MESON_GATE(CLKID_UART0, HHI_GCLK_MPEG0, 13),
+	MESON_GATE(CLKID_SDHC, HHI_GCLK_MPEG0, 14),
+	MESON_GATE(CLKID_STREAM, HHI_GCLK_MPEG0, 15),
+	MESON_GATE(CLKID_ASYNC_FIFO, HHI_GCLK_MPEG0, 16),
+	MESON_GATE(CLKID_SDIO, HHI_GCLK_MPEG0, 17),
+	MESON_GATE(CLKID_ABUF, HHI_GCLK_MPEG0, 18),
+	MESON_GATE(CLKID_HIU_IFACE, HHI_GCLK_MPEG0, 19),
+	MESON_GATE(CLKID_ASSIST_MISC, HHI_GCLK_MPEG0, 23),
+	MESON_GATE(CLKID_SD_EMMC_A, HHI_GCLK_MPEG0, 24),
+	MESON_GATE(CLKID_SD_EMMC_B, HHI_GCLK_MPEG0, 25),
+	MESON_GATE(CLKID_SD_EMMC_C, HHI_GCLK_MPEG0, 26),
+	MESON_GATE(CLKID_SPI, HHI_GCLK_MPEG0, 30),
+
+	MESON_GATE(CLKID_I2S_SPDIF, HHI_GCLK_MPEG1, 2),
+	MESON_GATE(CLKID_ETH, HHI_GCLK_MPEG1, 3),
+	MESON_GATE(CLKID_DEMUX, HHI_GCLK_MPEG1, 4),
+	MESON_GATE(CLKID_AIU_GLUE, HHI_GCLK_MPEG1, 6),
+	MESON_GATE(CLKID_IEC958, HHI_GCLK_MPEG1, 7),
+	MESON_GATE(CLKID_I2S_OUT, HHI_GCLK_MPEG1, 8),
+	MESON_GATE(CLKID_AMCLK, HHI_GCLK_MPEG1, 9),
+	MESON_GATE(CLKID_AIFIFO2, HHI_GCLK_MPEG1, 10),
+	MESON_GATE(CLKID_MIXER, HHI_GCLK_MPEG1, 11),
+	MESON_GATE(CLKID_MIXER_IFACE, HHI_GCLK_MPEG1, 12),
+	MESON_GATE(CLKID_ADC, HHI_GCLK_MPEG1, 13),
+	MESON_GATE(CLKID_BLKMV, HHI_GCLK_MPEG1, 14),
+	MESON_GATE(CLKID_AIU, HHI_GCLK_MPEG1, 15),
+	MESON_GATE(CLKID_UART1, HHI_GCLK_MPEG1, 16),
+	MESON_GATE(CLKID_G2D, HHI_GCLK_MPEG1, 20),
+	MESON_GATE(CLKID_USB0, HHI_GCLK_MPEG1, 21),
+	MESON_GATE(CLKID_USB1, HHI_GCLK_MPEG1, 22),
+	MESON_GATE(CLKID_RESET, HHI_GCLK_MPEG1, 23),
+	MESON_GATE(CLKID_NAND, HHI_GCLK_MPEG1, 24),
+	MESON_GATE(CLKID_DOS_PARSER, HHI_GCLK_MPEG1, 25),
+	MESON_GATE(CLKID_USB, HHI_GCLK_MPEG1, 26),
+	MESON_GATE(CLKID_VDIN1, HHI_GCLK_MPEG1, 28),
+	MESON_GATE(CLKID_AHB_ARB0, HHI_GCLK_MPEG1, 29),
+	MESON_GATE(CLKID_EFUSE, HHI_GCLK_MPEG1, 30),
+	MESON_GATE(CLKID_BOOT_ROM, HHI_GCLK_MPEG1, 31),
+
+	MESON_GATE(CLKID_AHB_DATA_BUS, HHI_GCLK_MPEG2, 1),
+	MESON_GATE(CLKID_AHB_CTRL_BUS, HHI_GCLK_MPEG2, 2),
+	MESON_GATE(CLKID_HDMI_INTR_SYNC, HHI_GCLK_MPEG2, 3),
+	MESON_GATE(CLKID_HDMI_PCLK, HHI_GCLK_MPEG2, 4),
+	MESON_GATE(CLKID_USB1_DDR_BRIDGE, HHI_GCLK_MPEG2, 8),
+	MESON_GATE(CLKID_USB0_DDR_BRIDGE, HHI_GCLK_MPEG2, 9),
+	MESON_GATE(CLKID_MMC_PCLK, HHI_GCLK_MPEG2, 11),
+	MESON_GATE(CLKID_DVIN, HHI_GCLK_MPEG2, 12),
+	MESON_GATE(CLKID_UART2, HHI_GCLK_MPEG2, 15),
+	MESON_GATE(CLKID_SANA, HHI_GCLK_MPEG2, 22),
+	MESON_GATE(CLKID_VPU_INTR, HHI_GCLK_MPEG2, 25),
+	MESON_GATE(CLKID_SEC_AHB_AHB3_BRIDGE, HHI_GCLK_MPEG2, 26),
+	MESON_GATE(CLKID_CLK81_A53, HHI_GCLK_MPEG2, 29),
+
+	MESON_GATE(CLKID_VCLK2_VENCI0, HHI_GCLK_OTHER, 1),
+	MESON_GATE(CLKID_VCLK2_VENCI1, HHI_GCLK_OTHER, 2),
+	MESON_GATE(CLKID_VCLK2_VENCP0, HHI_GCLK_OTHER, 3),
+	MESON_GATE(CLKID_VCLK2_VENCP1, HHI_GCLK_OTHER, 4),
+	MESON_GATE(CLKID_GCLK_VENCI_INT0, HHI_GCLK_OTHER, 8),
+	MESON_GATE(CLKID_DAC_CLK, HHI_GCLK_OTHER, 10),
+	MESON_GATE(CLKID_AOCLK_GATE, HHI_GCLK_OTHER, 14),
+	MESON_GATE(CLKID_IEC958_GATE, HHI_GCLK_OTHER, 16),
+	MESON_GATE(CLKID_ENC480P, HHI_GCLK_OTHER, 20),
+	MESON_GATE(CLKID_RNG1, HHI_GCLK_OTHER, 21),
+	MESON_GATE(CLKID_GCLK_VENCI_INT1, HHI_GCLK_OTHER, 22),
+	MESON_GATE(CLKID_VCLK2_VENCLMCC, HHI_GCLK_OTHER, 24),
+	MESON_GATE(CLKID_VCLK2_VENCL, HHI_GCLK_OTHER, 25),
+	MESON_GATE(CLKID_VCLK_OTHER, HHI_GCLK_OTHER, 26),
+	MESON_GATE(CLKID_EDP, HHI_GCLK_OTHER, 31),
+
+	/* Always On (AO) domain gates */
+	MESON_GATE(CLKID_AO_MEDIA_CPU, HHI_GCLK_AO, 0),
+	MESON_GATE(CLKID_AO_AHB_SRAM, HHI_GCLK_AO, 1),
+	MESON_GATE(CLKID_AO_AHB_BUS, HHI_GCLK_AO, 2),
+	MESON_GATE(CLKID_AO_IFACE, HHI_GCLK_AO, 3),
+	MESON_GATE(CLKID_AO_I2C, HHI_GCLK_AO, 4),
+};
+
+static int meson_set_gate(struct clk *clk, bool on)
+{
+	struct meson_clk *priv = dev_get_priv(clk->dev);
+	struct meson_gate *gate;
+
+	if (clk->id >= ARRAY_SIZE(gates))
+		return -ENOENT;
+
+	gate = &gates[clk->id];
+
+	if (gate->reg == 0)
+		return -ENOENT;
+
+	clrsetbits_le32(priv->addr + gate->reg,
+			BIT(gate->bit), on ? BIT(gate->bit) : 0);
+	return 0;
+}
+
+static int meson_clk_enable(struct clk *clk)
+{
+	return meson_set_gate(clk, true);
+}
+
+static int meson_clk_disable(struct clk *clk)
+{
+	return meson_set_gate(clk, false);
+}
+
+static ulong meson_clk_get_rate(struct clk *clk)
+{
+	struct meson_clk *priv = dev_get_priv(clk->dev);
+
+	if (clk->id != CLKID_CLK81) {
+		if (clk->id >= ARRAY_SIZE(gates))
+			return -ENOENT;
+		if (gates[clk->id].reg == 0)
+			return -ENOENT;
+	}
+
+	/* Use cached value if available */
+	if (priv->rate)
+		return priv->rate;
+
+	priv->rate = meson_measure_clk_rate(CLK_81);
+
+	return priv->rate;
+}
+
+static int meson_clk_probe(struct udevice *dev)
+{
+	struct meson_clk *priv = dev_get_priv(dev);
+
+	priv->addr = dev_read_addr_ptr(dev);
+	debug("meson-clk: probed at addr %p\n", priv->addr);
+
+	return 0;
+}
+
+static struct clk_ops meson_clk_ops = {
+	.disable	= meson_clk_disable,
+	.enable		= meson_clk_enable,
+	.get_rate	= meson_clk_get_rate,
+};
+
+static const struct udevice_id meson_clk_ids[] = {
+	{ .compatible = "amlogic,gxbb-clkc" },
+	{ .compatible = "amlogic,gxl-clkc" },
+	{ }
+};
+
+U_BOOT_DRIVER(meson_clk) = {
+	.name		= "meson_clk",
+	.id		= UCLASS_CLK,
+	.of_match	= meson_clk_ids,
+	.priv_auto_alloc_size = sizeof(struct meson_clk),
+	.ops		= &meson_clk_ops,
+	.probe		= meson_clk_probe,
+};
-- 
2.14.3