clk: renesas: cpg-mssr: Add R7S9210 support

Add support for the R7S9210 (RZ/A2) Clock Pulse Generator and Module
Standby.

The Module Standby HW in the RZ/A series is very close to R-Car HW, except
for how the registers are laid out.
The MSTP registers are only 8-bits wide, there are no status registers
(MSTPSR), and the register offsets are a little different. Since the RZ/A
hardware manuals refer to these registers as the Standby Control Registers,
we'll use that name to distinguish the RZ/A type from the R-Car type.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Acked-by: Rob Herring <robh@kernel.org> # DT bits
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

1 files changed, 189 insertions, 0 deletions

diff --git a/drivers/clk/renesas/r7s9210-cpg-mssr.c b/drivers/clk/renesas/r7s9210-cpg-mssr.c
new file mode 100644
index 000000000000..bd1dd4ff2051
--- /dev/null
+++ b/drivers/clk/renesas/r7s9210-cpg-mssr.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * R7S9210 Clock Pulse Generator / Module Standby
+ *
+ * Based on r8a7795-cpg-mssr.c
+ *
+ * Copyright (C) 2018 Chris Brandt
+ * Copyright (C) 2018 Renesas Electronics Corp.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <dt-bindings/clock/r7s9210-cpg-mssr.h>
+#include "renesas-cpg-mssr.h"
+
+#define CPG_FRQCR	0x00
+
+static u8 cpg_mode;
+
+/* Internal Clock ratio table */
+static const struct {
+	unsigned int i;
+	unsigned int g;
+	unsigned int b;
+	unsigned int p1;
+	/* p0 is always 32 */;
+} ratio_tab[5] = {	/* I,  G,  B, P1 */
+			{  2,  4,  8, 16},	/* FRQCR = 0x012 */
+			{  4,  4,  8, 16},	/* FRQCR = 0x112 */
+			{  8,  4,  8, 16},	/* FRQCR = 0x212 */
+			{ 16,  8, 16, 16},	/* FRQCR = 0x322 */
+			{ 16, 16, 32, 32},	/* FRQCR = 0x333 */
+			};
+
+enum rz_clk_types {
+	CLK_TYPE_RZA_MAIN = CLK_TYPE_CUSTOM,
+	CLK_TYPE_RZA_PLL,
+};
+
+enum clk_ids {
+	/* Core Clock Outputs exported to DT */
+	LAST_DT_CORE_CLK = R7S9210_CLK_P0,
+
+	/* External Input Clocks */
+	CLK_EXTAL,
+
+	/* Internal Core Clocks */
+	CLK_MAIN,
+	CLK_PLL,
+
+	/* Module Clocks */
+	MOD_CLK_BASE
+};
+
+static struct cpg_core_clk r7s9210_core_clks[] = {
+	/* External Clock Inputs */
+	DEF_INPUT("extal",     CLK_EXTAL),
+
+	/* Internal Core Clocks */
+	DEF_BASE(".main",       CLK_MAIN, CLK_TYPE_RZA_MAIN, CLK_EXTAL),
+	DEF_BASE(".pll",       CLK_PLL, CLK_TYPE_RZA_PLL, CLK_MAIN),
+
+	/* Core Clock Outputs */
+	DEF_FIXED("i",      R7S9210_CLK_I,     CLK_PLL,          2, 1),
+	DEF_FIXED("g",      R7S9210_CLK_G,     CLK_PLL,          4, 1),
+	DEF_FIXED("b",      R7S9210_CLK_B,     CLK_PLL,          8, 1),
+	DEF_FIXED("p1",     R7S9210_CLK_P1,    CLK_PLL,         16, 1),
+	DEF_FIXED("p1c",    R7S9210_CLK_P1C,   CLK_PLL,         16, 1),
+	DEF_FIXED("p0",     R7S9210_CLK_P0,    CLK_PLL,         32, 1),
+};
+
+static const struct mssr_mod_clk r7s9210_mod_clks[] __initconst = {
+	DEF_MOD_STB("ostm2",	 34,	R7S9210_CLK_P1C),
+	DEF_MOD_STB("ostm1",	 35,	R7S9210_CLK_P1C),
+	DEF_MOD_STB("ostm0",	 36,	R7S9210_CLK_P1C),
+
+	DEF_MOD_STB("scif4",	 43,	R7S9210_CLK_P1C),
+	DEF_MOD_STB("scif3",	 44,	R7S9210_CLK_P1C),
+	DEF_MOD_STB("scif2",	 45,	R7S9210_CLK_P1C),
+	DEF_MOD_STB("scif1",	 46,	R7S9210_CLK_P1C),
+	DEF_MOD_STB("scif0",	 47,	R7S9210_CLK_P1C),
+
+	DEF_MOD_STB("ether1",	 64,	R7S9210_CLK_B),
+	DEF_MOD_STB("ether0",	 65,	R7S9210_CLK_B),
+
+	DEF_MOD_STB("i2c3",	 84,	R7S9210_CLK_P1),
+	DEF_MOD_STB("i2c2",	 85,	R7S9210_CLK_P1),
+	DEF_MOD_STB("i2c1",	 86,	R7S9210_CLK_P1),
+	DEF_MOD_STB("i2c0",	 87,	R7S9210_CLK_P1),
+
+};
+
+struct clk * __init rza2_cpg_clk_register(struct device *dev,
+	const struct cpg_core_clk *core, const struct cpg_mssr_info *info,
+	struct clk **clks, void __iomem *base,
+	struct raw_notifier_head *notifiers)
+{
+	struct clk *parent;
+	unsigned int mult = 1;
+	unsigned int div = 1;
+	u16 frqcr;
+	u8 index;
+	int i;
+
+	parent = clks[core->parent];
+	if (IS_ERR(parent))
+		return ERR_CAST(parent);
+
+	switch (core->id) {
+	case CLK_MAIN:
+		break;
+
+	case CLK_PLL:
+		if (cpg_mode)
+			mult = 44;	/* Divider 1 is 1/2 */
+		else
+			mult = 88;	/* Divider 1 is 1 */
+		break;
+
+	default:
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* Adjust the dividers based on the current FRQCR setting */
+	if (core->id == CLK_MAIN) {
+
+		/* If EXTAL is above 12MHz, then we know it is Mode 1 */
+		if (clk_get_rate(parent) > 12000000)
+			cpg_mode = 1;
+
+		frqcr = clk_readl(base + CPG_FRQCR) & 0xFFF;
+		if (frqcr == 0x012)
+			index = 0;
+		else if (frqcr == 0x112)
+			index = 1;
+		else if (frqcr == 0x212)
+			index = 2;
+		else if (frqcr == 0x322)
+			index = 3;
+		else if (frqcr == 0x333)
+			index = 4;
+		else
+			BUG_ON(1);	/* Illegal FRQCR value */
+
+		for (i = 0; i < ARRAY_SIZE(r7s9210_core_clks); i++) {
+			switch (r7s9210_core_clks[i].id) {
+			case R7S9210_CLK_I:
+				r7s9210_core_clks[i].div = ratio_tab[index].i;
+				break;
+			case R7S9210_CLK_G:
+				r7s9210_core_clks[i].div = ratio_tab[index].g;
+				break;
+			case R7S9210_CLK_B:
+				r7s9210_core_clks[i].div = ratio_tab[index].b;
+				break;
+			case R7S9210_CLK_P1:
+			case R7S9210_CLK_P1C:
+				r7s9210_core_clks[i].div = ratio_tab[index].p1;
+				break;
+			case R7S9210_CLK_P0:
+				r7s9210_core_clks[i].div = 32;
+				break;
+			}
+		}
+	}
+
+	return clk_register_fixed_factor(NULL, core->name,
+					 __clk_get_name(parent), 0, mult, div);
+}
+
+const struct cpg_mssr_info r7s9210_cpg_mssr_info __initconst = {
+	/* Core Clocks */
+	.core_clks = r7s9210_core_clks,
+	.num_core_clks = ARRAY_SIZE(r7s9210_core_clks),
+	.last_dt_core_clk = LAST_DT_CORE_CLK,
+	.num_total_core_clks = MOD_CLK_BASE,
+
+	/* Module Clocks */
+	.mod_clks = r7s9210_mod_clks,
+	.num_mod_clks = ARRAY_SIZE(r7s9210_mod_clks),
+	.num_hw_mod_clks = 11 * 32, /* includes STBCR0 which doesn't exist */
+
+	/* Callbacks */
+	.cpg_clk_register = rza2_cpg_clk_register,
+
+	/* RZ/A2 has Standby Control Registers */
+	.stbyctrl = true,
+};