clk: sunxi-ng: add support for H6 PRCM CCU

The H6 has clock/reset controls in PRCM part, like old SoCs such as H3
and A64. However, the PRCM CCU is rearranged; the register arragement
is now similar to the main CCU of H6, and the PRCM now has two APB
buses to control -- one is clocked from AHB clock derivde from AR100
clock, the other is clocked from the same mux with AR100 clock.
Therefore a new driver is written for it.

As there's no official document about the PRCM in H6, all the information
are indirectly collected from BSP and parts of the document, and the
information source is noted as comments in the driver's source code. If
reliable information is provided furtherly, the driver needs to be
rechecked.

Signed-off-by: Icenowy Zheng <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>

Documentation/devicetree/bindings/clock/sunxi-ccu.txt

···
 		- "allwinner,sun50i-a64-r-ccu"
 		- "allwinner,sun50i-h5-ccu"
 		- "allwinner,sun50i-h6-ccu"
+		- "allwinner,sun50i-h6-r-ccu"
 		- "nextthing,gr8-ccu"
 
 - reg: Must contain the registers base address and length
···
 For the main CCU on H6, one more clock is needed:
 - "iosc": the SoC's internal frequency oscillator
 
-For the PRCM CCUs on A83T/H3/A64, two more clocks are needed:
+For the PRCM CCUs on A83T/H3/A64/H6, two more clocks are needed:
 - "pll-periph": the SoC's peripheral PLL from the main CCU
 - "iosc": the SoC's internal frequency oscillator
 

drivers/clk/sunxi-ng/Kconfig

···
 	default ARM64 && ARCH_SUNXI
 	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
 
+config SUN50I_H6_R_CCU
+	bool "Support for the Allwinner H6 PRCM CCU"
+	default ARM64 && ARCH_SUNXI
+	depends on (ARM64 && ARCH_SUNXI) || COMPILE_TEST
+
 config SUN4I_A10_CCU
 	bool "Support for the Allwinner A10/A20 CCU"
 	default MACH_SUN4I

drivers/clk/sunxi-ng/Makefile

···
 # SoC support
 obj-$(CONFIG_SUN50I_A64_CCU)	+= ccu-sun50i-a64.o
 obj-$(CONFIG_SUN50I_H6_CCU)	+= ccu-sun50i-h6.o
+obj-$(CONFIG_SUN50I_H6_R_CCU)	+= ccu-sun50i-h6-r.o
 obj-$(CONFIG_SUN4I_A10_CCU)	+= ccu-sun4i-a10.o
 obj-$(CONFIG_SUN5I_CCU)		+= ccu-sun5i.o
 obj-$(CONFIG_SUN6I_A31_CCU)	+= ccu-sun6i-a31.o

drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2017 Icenowy Zheng <[e-mail]>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+
+#include "ccu_common.h"
+#include "ccu_reset.h"
+
+#include "ccu_div.h"
+#include "ccu_gate.h"
+#include "ccu_mp.h"
+#include "ccu_nm.h"
+
+#include "ccu-sun50i-h6-r.h"
+
+/*
+ * Information about AR100 and AHB/APB clocks in R_CCU are gathered from
+ * clock definitions in the BSP source code.
+ */
+
+static const char * const ar100_r_apb2_parents[] = { "osc24M", "osc32k",
+					     "pll-periph0", "iosc" };
+static const struct ccu_mux_var_prediv ar100_r_apb2_predivs[] = {
+	{ .index = 2, .shift = 0, .width = 5 },
+};
+
+static struct ccu_div ar100_clk = {
+	.div		= _SUNXI_CCU_DIV_FLAGS(8, 2, CLK_DIVIDER_POWER_OF_TWO),
+
+	.mux		= {
+		.shift	= 24,
+		.width	= 2,
+
+		.var_predivs	= ar100_r_apb2_predivs,
+		.n_var_predivs	= ARRAY_SIZE(ar100_r_apb2_predivs),
+	},
+
+	.common		= {
+		.reg		= 0x000,
+		.features	= CCU_FEATURE_VARIABLE_PREDIV,
+		.hw.init	= CLK_HW_INIT_PARENTS("ar100",
+						      ar100_r_apb2_parents,
+						      &ccu_div_ops,
+						      0),
+	},
+};
+
+static CLK_FIXED_FACTOR(r_ahb_clk, "r-ahb", "ar100", 1, 1, 0);
+
+static struct ccu_div r_apb1_clk = {
+	.div		= _SUNXI_CCU_DIV(0, 2),
+
+	.common		= {
+		.reg		= 0x00c,
+		.hw.init	= CLK_HW_INIT("r-apb1",
+					      "r-ahb",
+					      &ccu_div_ops,
+					      0),
+	},
+};
+
+static struct ccu_div r_apb2_clk = {
+	.div		= _SUNXI_CCU_DIV_FLAGS(8, 2, CLK_DIVIDER_POWER_OF_TWO),
+
+	.mux		= {
+		.shift	= 24,
+		.width	= 2,
+
+		.var_predivs	= ar100_r_apb2_predivs,
+		.n_var_predivs	= ARRAY_SIZE(ar100_r_apb2_predivs),
+	},
+
+	.common		= {
+		.reg		= 0x010,
+		.features	= CCU_FEATURE_VARIABLE_PREDIV,
+		.hw.init	= CLK_HW_INIT_PARENTS("r-apb2",
+						      ar100_r_apb2_parents,
+						      &ccu_div_ops,
+						      0),
+	},
+};
+
+/*
+ * Information about the gate/resets are gathered from the clock header file
+ * in the BSP source code, although most of them are unused. The existence
+ * of the hardware block is verified with "3.1 Memory Mapping" chapter in
+ * "Allwinner H6 V200 User Manual V1.1"; and the parent APB buses are verified
+ * with "3.3.2.1 System Bus Tree" chapter inthe same document.
+ */
+static SUNXI_CCU_GATE(r_apb1_timer_clk,	"r-apb1-timer",	"r-apb1",
+		      0x11c, BIT(0), 0);
+static SUNXI_CCU_GATE(r_apb1_twd_clk,	"r-apb1-twd",	"r-apb1",
+		      0x12c, BIT(0), 0);
+static SUNXI_CCU_GATE(r_apb1_pwm_clk,	"r-apb1-pwm",	"r-apb1",
+		      0x13c, BIT(0), 0);
+static SUNXI_CCU_GATE(r_apb2_uart_clk,	"r-apb2-uart",	"r-apb2",
+		      0x18c, BIT(0), 0);
+static SUNXI_CCU_GATE(r_apb2_i2c_clk,	"r-apb2-i2c",	"r-apb2",
+		      0x19c, BIT(0), 0);
+static SUNXI_CCU_GATE(r_apb1_ir_clk,	"r-apb1-ir",	"r-apb1",
+		      0x1cc, BIT(0), 0);
+static SUNXI_CCU_GATE(r_apb1_w1_clk,	"r-apb1-w1",	"r-apb1",
+		      0x1cc, BIT(0), 0);
+
+/* Information of IR(RX) mod clock is gathered from BSP source code */
+static const char * const r_mod0_default_parents[] = { "osc32k", "osc24M" };
+static SUNXI_CCU_MP_WITH_MUX_GATE(ir_clk, "ir",
+				  r_mod0_default_parents, 0x1c0,
+				  0, 5,		/* M */
+				  8, 2,		/* P */
+				  24, 1,	/* mux */
+				  BIT(31),	/* gate */
+				  0);
+
+/*
+ * BSP didn't use the 1-wire function at all now, and the information about
+ * this mod clock is guessed from the IR mod clock above. The existence of
+ * this mod clock is proven by BSP clock header, and the dividers are verified
+ * by contents in the 1-wire related chapter of the User Manual.
+ */
+
+static SUNXI_CCU_MP_WITH_MUX_GATE(w1_clk, "w1",
+				  r_mod0_default_parents, 0x1e0,
+				  0, 5,		/* M */
+				  8, 2,		/* P */
+				  24, 1,	/* mux */
+				  BIT(31),	/* gate */
+				  0);
+
+static struct ccu_common *sun50i_h6_r_ccu_clks[] = {
+	&ar100_clk.common,
+	&r_apb1_clk.common,
+	&r_apb2_clk.common,
+	&r_apb1_timer_clk.common,
+	&r_apb1_twd_clk.common,
+	&r_apb1_pwm_clk.common,
+	&r_apb2_uart_clk.common,
+	&r_apb2_i2c_clk.common,
+	&r_apb1_ir_clk.common,
+	&r_apb1_w1_clk.common,
+	&ir_clk.common,
+	&w1_clk.common,
+};
+
+static struct clk_hw_onecell_data sun50i_h6_r_hw_clks = {
+	.hws	= {
+		[CLK_AR100]		= &ar100_clk.common.hw,
+		[CLK_R_AHB]		= &r_ahb_clk.hw,
+		[CLK_R_APB1]		= &r_apb1_clk.common.hw,
+		[CLK_R_APB2]		= &r_apb2_clk.common.hw,
+		[CLK_R_APB1_TIMER]	= &r_apb1_timer_clk.common.hw,
+		[CLK_R_APB1_TWD]	= &r_apb1_twd_clk.common.hw,
+		[CLK_R_APB1_PWM]	= &r_apb1_pwm_clk.common.hw,
+		[CLK_R_APB2_UART]	= &r_apb2_uart_clk.common.hw,
+		[CLK_R_APB2_I2C]	= &r_apb2_i2c_clk.common.hw,
+		[CLK_R_APB1_IR]		= &r_apb1_ir_clk.common.hw,
+		[CLK_R_APB1_W1]		= &r_apb1_w1_clk.common.hw,
+		[CLK_IR]		= &ir_clk.common.hw,
+		[CLK_W1]		= &w1_clk.common.hw,
+	},
+	.num	= CLK_NUMBER,
+};
+
+static struct ccu_reset_map sun50i_h6_r_ccu_resets[] = {
+	[RST_R_APB1_TIMER]	=  { 0x11c, BIT(16) },
+	[RST_R_APB1_TWD]	=  { 0x12c, BIT(16) },
+	[RST_R_APB1_PWM]	=  { 0x13c, BIT(16) },
+	[RST_R_APB2_UART]	=  { 0x18c, BIT(16) },
+	[RST_R_APB2_I2C]	=  { 0x19c, BIT(16) },
+	[RST_R_APB1_IR]		=  { 0x1cc, BIT(16) },
+	[RST_R_APB1_W1]		=  { 0x1ec, BIT(16) },
+};
+
+static const struct sunxi_ccu_desc sun50i_h6_r_ccu_desc = {
+	.ccu_clks	= sun50i_h6_r_ccu_clks,
+	.num_ccu_clks	= ARRAY_SIZE(sun50i_h6_r_ccu_clks),
+
+	.hw_clks	= &sun50i_h6_r_hw_clks,
+
+	.resets		= sun50i_h6_r_ccu_resets,
+	.num_resets	= ARRAY_SIZE(sun50i_h6_r_ccu_resets),
+};
+
+static void __init sunxi_r_ccu_init(struct device_node *node,
+				    const struct sunxi_ccu_desc *desc)
+{
+	void __iomem *reg;
+
+	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
+	if (IS_ERR(reg)) {
+		pr_err("%pOF: Could not map the clock registers\n", node);
+		return;
+	}
+
+	sunxi_ccu_probe(node, reg, desc);
+}
+
+static void __init sun50i_h6_r_ccu_setup(struct device_node *node)
+{
+	sunxi_r_ccu_init(node, &sun50i_h6_r_ccu_desc);
+}
+CLK_OF_DECLARE(sun50i_h6_r_ccu, "allwinner,sun50i-h6-r-ccu",
+	       sun50i_h6_r_ccu_setup);

drivers/clk/sunxi-ng/ccu-sun50i-h6-r.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2017 Icenowy Zheng <[e-mail]>
+ */
+
+#ifndef _CCU_SUN50I_H6_R_H
+#define _CCU_SUN50I_H6_R_H
+
+#include <dt-bindings/clock/sun50i-h6-r-ccu.h>
+#include <dt-bindings/reset/sun50i-h6-r-ccu.h>
+
+/* AHB/APB bus clocks are not exported except APB1 for R_PIO */
+#define CLK_R_AHB	1
+
+#define CLK_R_APB2	3
+
+#define CLK_NUMBER	(CLK_W1 + 1)
+
+#endif /* _CCU_SUN50I_H6_R_H */

include/dt-bindings/clock/sun50i-h6-r-ccu.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2017 Icenowy Zheng <[e-mail]>
+ */
+
+#ifndef _DT_BINDINGS_CLK_SUN50I_H6_R_CCU_H_
+#define _DT_BINDINGS_CLK_SUN50I_H6_R_CCU_H_
+
+#define CLK_AR100		0
+
+#define CLK_R_APB1		2
+
+#define CLK_R_APB1_TIMER	4
+#define CLK_R_APB1_TWD		5
+#define CLK_R_APB1_PWM		6
+#define CLK_R_APB2_UART		7
+#define CLK_R_APB2_I2C		8
+#define CLK_R_APB1_IR		9
+#define CLK_R_APB1_W1		10
+
+#define CLK_IR			11
+#define CLK_W1			12
+
+#endif /* _DT_BINDINGS_CLK_SUN50I_H6_R_CCU_H_ */

include/dt-bindings/reset/sun50i-h6-r-ccu.h

···
+/* SPDX-License-Identifier: (GPL-2.0+ or MIT) */
+/*
+ * Copyright (C) 2016 Icenowy Zheng <[e-mail]>
+ */
+
+#ifndef _DT_BINDINGS_RST_SUN50I_H6_R_CCU_H_
+#define _DT_BINDINGS_RST_SUN50I_H6_R_CCU_H_
+
+#define RST_R_APB1_TIMER	0
+#define RST_R_APB1_TWD		1
+#define RST_R_APB1_PWM		2
+#define RST_R_APB2_UART		3
+#define RST_R_APB2_I2C		4
+#define RST_R_APB1_IR		5
+#define RST_R_APB1_W1		6
+
+#endif /* _DT_BINDINGS_RST_SUN50I_H6_R_CCU_H_ */