[PATCH v8 02/05] clk: shmobile: Add Renesas R-Car Gen3 CPG support

Magnus Damm
2015-10-01T14:37:38Z

From: Magnus Damm <damm+renesas@opensource.se>

This V8 patch adds initial CPG support for R-Car Generation 3 and in
particular the R8A7795 SoC.

The R-Car Gen3 clock hardware has a register write protection feature that
needs to be shared between the CPG function and the MSTP hardware somehow.
So far this feature is simply ignored.

Signed-off-by: Gaku Inami <gaku.inami.xw@bp.renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

Changes since V7: (Magnus Damm <damm+renesas@opensource.se>)
- Removed clk-mstp.o from r8a7795 Makefile
- Moved to earlier in the series

Changes since V6: (Magnus Damm <damm+renesas@opensource.se>)
- Moved PLL1 div-by-2 unit to outside of the CPG - thanks Laurent!
- Updated table to reflect PLL1 divider move.
- Reworked clock registration loop to prevent re-registering clocks.

Changes since V5: (Magnus Damm <damm+renesas@opensource.se>)
- Removed unused spinlock, use 0x3f as mask - thanks Laurent!
- Fixed space -> tab for DT binding documentation - thanks Geert!
- Postponed PLL1 divide-by-2 rewrite - requires a tad more effort.
- Updated commit log

Changes since V4: (Magnus Damm <damm+renesas@opensource.se>)
- Simplified clks array handling - thanks Geert!
- Updated th DT binding documentation to reflect latest state
- of_property_count_strings() -> of_property_count_u32_elems() fix

Changes since V3: (Magnus Damm <damm+renesas@opensource.se>)
- Reworked driver to incorporate most feedback from Stephen Boyd - thanks!!
- Major things like syscon and driver model require more discussion.
- Added hunk to build drivers/clk/shmobile if ARCH_RENESAS is set.

Changes since V2: (Magnus Damm <damm+renesas@opensource.se>)
- Reworked driver to rely on clock index instead of strings.
- Dropped use of "clock-output-names".

Earlier versions: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Initial version: Gaku Inami <gaku.inami.xw@bp.renesas.com>

Documentation/devicetree/bindings/clock/renesas,rcar-gen3-cpg-clocks.txt | 32 +
drivers/clk/Makefile | 1
drivers/clk/shmobile/Makefile | 1
drivers/clk/shmobile/clk-rcar-gen3.c | 242 ++++++++++
4 files changed, 276 insertions(+)

--- /dev/null
+++ work/Documentation/devicetree/bindings/clock/renesas,rcar-gen3-cpg-clocks.txt 2015-10-01 18:42:49.020513000 +0900
@@ -0,0 +1,32 @@
+* Renesas R-Car Gen3 Clock Pulse Generator (CPG)
+
+The CPG generates core clocks for the R-Car Gen3 SoCs. It includes three PLLs
+and several fixed ratio dividers.
+
+Required Properties:
+
+ - compatible: Must be one of
+ - "renesas,r8a7795-cpg-clocks" for the r8a7795 CPG
+ - "renesas,rcar-gen3-cpg-clocks" for the generic R-Car Gen3 CPG
+
+ - reg: Base address and length of the memory resource used by the CPG
+
+ - clocks: References to the parent clocks: first to the EXTAL clock
+ - #clock-cells: Must be 1
+ - clock-indices: Indices of the exported clocks
+
+Example
+-------
+
+ cpg_clocks: cpg_clocks@e6150000 {
+ compatible = "renesas,r8a7795-cpg-clocks",
+ "renesas,rcar-gen3-cpg-clocks";
+ reg = <0 0xe6150000 0 0x1000>;
+ clocks = <&extal_clk>;
+ #clock-cells = <1>;
+ clock-indices = <
+ R8A7795_CLK_MAIN R8A7795_CLK_PLL0
+ R8A7795_CLK_PLL1 R8A7795_CLK_PLL2
+ R8A7795_CLK_PLL3 R8A7795_CLK_PLL4
+ >;
+ };
--- 0001/drivers/clk/Makefile
+++ work/drivers/clk/Makefile 2015-10-01 18:42:48.000513000 +0900
@@ -67,6 +67,7 @@ obj-$(CONFIG_COMMON_CLK_QCOM) += qcom/
obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
obj-$(CONFIG_COMMON_CLK_SAMSUNG) += samsung/
obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += shmobile/
+obj-$(CONFIG_ARCH_RENESAS) += shmobile/
obj-$(CONFIG_ARCH_SIRF) += sirf/
obj-$(CONFIG_ARCH_SOCFPGA) += socfpga/
obj-$(CONFIG_PLAT_SPEAR) += spear/
--- 0002/drivers/clk/shmobile/Makefile
+++ work/drivers/clk/shmobile/Makefile 2015-10-01 18:42:59.670513000 +0900
@@ -8,4 +8,5 @@ obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-
obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o clk-mstp.o clk-div6.o
obj-$(CONFIG_ARCH_R8A7793) += clk-rcar-gen2.o clk-mstp.o clk-div6.o
obj-$(CONFIG_ARCH_R8A7794) += clk-rcar-gen2.o clk-mstp.o clk-div6.o
+obj-$(CONFIG_ARCH_R8A7795) += clk-rcar-gen3.o clk-div6.o
obj-$(CONFIG_ARCH_SH73A0) += clk-sh73a0.o clk-mstp.o clk-div6.o
--- /dev/null
+++ work/drivers/clk/shmobile/clk-rcar-gen3.c 2015-10-01 18:42:49.020513000 +0900
@@ -0,0 +1,242 @@
+/*
+ * rcar_gen3 Core CPG Clocks
+ *
+ * Copyright (C) 2015 Renesas Electronics Corp.
+ *
+ * Based on rcar_gen2 Core CPG Clocks driver.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clk/shmobile.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#define RCAR_GEN3_CLK_MAIN 0
+#define RCAR_GEN3_CLK_PLL0 1
+#define RCAR_GEN3_CLK_PLL1 2
+#define RCAR_GEN3_CLK_PLL2 3
+#define RCAR_GEN3_CLK_PLL3 4
+#define RCAR_GEN3_CLK_PLL4 5
+#define RCAR_GEN3_CLK_NR 6
+
+static const char * const rcar_gen3_clk_names[RCAR_GEN3_CLK_NR] = {
+ [RCAR_GEN3_CLK_MAIN] = "main",
+ [RCAR_GEN3_CLK_PLL0] = "pll0",
+ [RCAR_GEN3_CLK_PLL1] = "pll1",
+ [RCAR_GEN3_CLK_PLL2] = "pll2",
+ [RCAR_GEN3_CLK_PLL3] = "pll3",
+ [RCAR_GEN3_CLK_PLL4] = "pll4",
+};
+
+struct rcar_gen3_cpg {
+ struct clk_onecell_data data;
+ void __iomem *reg;
+ struct clk *clks[RCAR_GEN3_CLK_NR];
+};
+
+#define CPG_PLL0CR 0x00d8
+#define CPG_PLL2CR 0x002c
+
+/*
+ * common function
+ */
+#define rcar_clk_readl(cpg, _reg) readl(cpg->reg + _reg)
+
+/*
+ * Reset register definitions.
+ */
+#define MODEMR 0xe6160060
+
+static u32 rcar_gen3_read_mode_pins(void)
+{
+ static u32 mode;
+ static bool mode_valid;
+
+ if (!mode_valid) {
+ void __iomem *modemr = ioremap_nocache(MODEMR, 4);
+
+ BUG_ON(!modemr);
+ mode = ioread32(modemr);
+ iounmap(modemr);
+ mode_valid = true;
+ }
+
+ return mode;
+}
+
+/* -----------------------------------------------------------------------------
+ * CPG Clock Data
+ */
+
+/*
+ * MD EXTAL PLL0 PLL1 PLL2 PLL3 PLL4
+ * 14 13 19 17 (MHz)
+ *-------------------------------------------------------------------
+ * 0 0 0 0 16.66 x 1 x180 x192 x144 x192 x144
+ * 0 0 0 1 16.66 x 1 x180 x192 x144 x128 x144
+ * 0 0 1 0 Prohibited setting
+ * 0 0 1 1 16.66 x 1 x180 x192 x144 x192 x144
+ * 0 1 0 0 20 x 1 x150 x156 x120 x156 x120
+ * 0 1 0 1 20 x 1 x150 x156 x120 x106 x120
+ * 0 1 1 0 Prohibited setting
+ * 0 1 1 1 20 x 1 x150 x156 x120 x156 x120
+ * 1 0 0 0 25 x 1 x120 x128 x96 x128 x96
+ * 1 0 0 1 25 x 1 x120 x128 x96 x84 x96
+ * 1 0 1 0 Prohibited setting
+ * 1 0 1 1 25 x 1 x120 x128 x96 x128 x96
+ * 1 1 0 0 33.33 / 2 x180 x192 x144 x192 x144
+ * 1 1 0 1 33.33 / 2 x180 x192 x144 x128 x144
+ * 1 1 1 0 Prohibited setting
+ * 1 1 1 1 33.33 / 2 x180 x192 x144 x192 x144
+ */
+#define CPG_PLL_CONFIG_INDEX(md) ((((md) & BIT(14)) >> 11) | \
+ (((md) & BIT(13)) >> 11) | \
+ (((md) & BIT(19)) >> 18) | \
+ (((md) & BIT(17)) >> 17))
+struct cpg_pll_config {
+ unsigned int extal_div;
+ unsigned int pll1_mult;
+ unsigned int pll3_mult;
+ unsigned int pll4_mult;
+};
+
+static const struct cpg_pll_config cpg_pll_configs[16] __initconst = {
+/* EXTAL div PLL1 PLL3 PLL4 */
+ { 1, 192, 192, 144, },
+ { 1, 192, 128, 144, },
+ { 0, 0, 0, 0, }, /* Prohibited setting */
+ { 1, 192, 192, 144, },
+ { 1, 156, 156, 120, },
+ { 1, 156, 106, 120, },
+ { 0, 0, 0, 0, }, /* Prohibited setting */
+ { 1, 156, 156, 120, },
+ { 1, 128, 128, 96, },
+ { 1, 128, 84, 96, },
+ { 0, 0, 0, 0, }, /* Prohibited setting */
+ { 1, 128, 128, 96, },
+ { 2, 192, 192, 144, },
+ { 2, 192, 128, 144, },
+ { 0, 0, 0, 0, }, /* Prohibited setting */
+ { 2, 192, 192, 144, },
+};
+
+/* -----------------------------------------------------------------------------
+ * Initialization
+ */
+
+static struct clk * __init
+rcar_gen3_cpg_register_clk(struct device_node *np, struct rcar_gen3_cpg *cpg,
+ const struct cpg_pll_config *config,
+ unsigned int gen3_clk)
+{
+ const char *parent_name = rcar_gen3_clk_names[RCAR_GEN3_CLK_MAIN];
+ unsigned int mult = 1;
+ unsigned int div = 1;
+ u32 value;
+
+ switch (gen3_clk) {
+ case RCAR_GEN3_CLK_MAIN:
+ parent_name = of_clk_get_parent_name(np, 0);
+ div = config->extal_div;
+ break;
+ case RCAR_GEN3_CLK_PLL0:
+ /* PLL0 is a configurable multiplier clock. Register it as a
+ * fixed factor clock for now as there's no generic multiplier
+ * clock implementation and we currently have no need to change
+ * the multiplier value.
+ */
+ value = rcar_clk_readl(cpg, CPG_PLL0CR);
+ mult = ((value >> 24) & 0x3f) + 1;
+ break;
+ case RCAR_GEN3_CLK_PLL1:
+ mult = config->pll1_mult;
+ break;
+ case RCAR_GEN3_CLK_PLL2:
+ /* PLL2 is a configurable multiplier clock. Register it as a
+ * fixed factor clock for now as there's no generic multiplier
+ * clock implementation and we currently have no need to change
+ * the multiplier value.
+ */
+ value = rcar_clk_readl(cpg, CPG_PLL2CR);
+ mult = ((value >> 24) & 0x3f) + 1;
+ break;
+ case RCAR_GEN3_CLK_PLL3:
+ mult = config->pll3_mult;
+ break;
+ case RCAR_GEN3_CLK_PLL4:
+ mult = config->pll4_mult;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ return clk_register_fixed_factor(NULL, rcar_gen3_clk_names[gen3_clk],
+ parent_name, 0, mult, div);
+}
+
+static void __init rcar_gen3_cpg_clocks_init(struct device_node *np)
+{
+ const struct cpg_pll_config *config;
+ struct rcar_gen3_cpg *cpg;
+ u32 cpg_mode;
+ unsigned int i;
+
+ cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
+ if (!cpg)
+ return;
+
+ cpg->reg = of_iomap(np, 0);
+ if (WARN_ON(cpg->reg == NULL))
+ return;
+
+ cpg_mode = rcar_gen3_read_mode_pins();
+
+ config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)];
+ if (!config->extal_div) {
+ pr_err("%s: Prohibited setting (cpg_mode=0x%x)\n",
+ __func__, cpg_mode);
+ return;
+ }
+
+ for (i = 0; i < RCAR_GEN3_CLK_NR; ++i)
+ cpg->clks[i] = ERR_PTR(-ENOENT);
+
+ for (i = 0; i < RCAR_GEN3_CLK_NR; ++i) {
+ struct clk *clk;
+ u32 idx;
+ int ret;
+
+ ret = of_property_read_u32_index(np, "clock-indices", i, &idx);
+ if (ret < 0)
+ break;
+
+ if (idx >= RCAR_GEN3_CLK_NR) {
+ pr_err("%s: skipping unsupported %u\n", __func__, idx);
+ } else if (cpg->clks[idx] != ERR_PTR(-ENOENT)) {
+ pr_err("%s: skipping already registered %u\n",
+ __func__, idx);
+ } else {
+ clk = rcar_gen3_cpg_register_clk(np, cpg, config, idx);
+
+ if (IS_ERR(clk))
+ pr_err("%s: unable to register %u (%ld)\n",
+ __func__, idx, PTR_ERR(clk));
+ else
+ cpg->clks[idx] = clk;
+ }
+ }
+
+ cpg->data.clks = cpg->clks;
+ cpg->data.clk_num = i;
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
+}
+CLK_OF_DECLARE(rcar_gen3_cpg_clks, "renesas,rcar-gen3-cpg-clocks",
+ rcar_gen3_cpg_clocks_init);