[PATCH v4 1/3] clk: shmobile: Add R-Car Gen2 clocks support
Laurent Pinchart
laurent.pinchart+renesas at ideasonboard.com
Mon Dec 2 08:34:15 EST 2013
The R-Car Gen2 SoCs (R8A7790 and R8A7791) have several clocks that are
too custom to be supported in a generic driver. Those clocks can be
divided in two categories:
- Fixed rate clocks with multiplier and divisor set according to boot
mode configuration
- Custom divider clocks with SoC-specific divider values
This driver supports both.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas at ideasonboard.com>
Acked-by: Kumar Gala <galak at codeaurora.org>
---
.../clock/renesas,rcar-gen2-cpg-clocks.txt | 32 +++
drivers/clk/Makefile | 1 +
drivers/clk/shmobile/Makefile | 5 +
drivers/clk/shmobile/clk-rcar-gen2.c | 298 +++++++++++++++++++++
include/linux/clk/shmobile.h | 19 ++
5 files changed, 355 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
create mode 100644 drivers/clk/shmobile/Makefile
create mode 100644 drivers/clk/shmobile/clk-rcar-gen2.c
create mode 100644 include/linux/clk/shmobile.h
diff --git a/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
new file mode 100644
index 0000000..7b41c2f
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/renesas,rcar-gen2-cpg-clocks.txt
@@ -0,0 +1,32 @@
+* Renesas R-Car Gen2 Clock Pulse Generator (CPG)
+
+The CPG generates core clocks for the R-Car Gen2 SoCs. It includes three PLLs
+and several fixed ratio dividers.
+
+Required Properties:
+
+ - compatible: Must be one of
+ - "renesas,r8a7790-cpg-clocks" for the r8a7790 CPG
+ - "renesas,r8a7791-cpg-clocks" for the r8a7791 CPG
+ - "renesas,rcar-gen2-cpg-clocks" for the generic R-Car Gen2 CPG
+
+ - reg: Base address and length of the memory resource used by the CPG
+
+ - clocks: Reference to the parent clock
+ - #clock-cells: Must be 1
+ - clock-output-names: The names of the clocks. Supported clocks are "main",
+ "pll0", "pll1", "pll3", "lb", "qspi", "sdh", "sd0", "sd1" and "z"
+
+
+Example
+-------
+
+ cpg_clocks: cpg_clocks at e6150000 {
+ compatible = "renesas,r8a7790-cpg-clocks",
+ "renesas,rcar-gen2-cpg-clocks";
+ reg = <0 0xe6150000 0 0x1000>;
+ clocks = <&extal_clk>;
+ #clock-cells = <1>;
+ clock-output-names = "main", "pll0, "pll1", "pll3",
+ "lb", "qspi", "sdh", "sd0", "sd1", "z";
+ };
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 7a10bc9..b0a71ff 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_ARCH_SIRF) += clk-prima2.o
obj-$(CONFIG_PLAT_ORION) += mvebu/
ifeq ($(CONFIG_COMMON_CLK), y)
obj-$(CONFIG_ARCH_MMP) += mmp/
+obj-$(CONFIG_ARCH_SHMOBILE) += shmobile/
endif
obj-$(CONFIG_MACH_LOONGSON1) += clk-ls1x.o
obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
diff --git a/drivers/clk/shmobile/Makefile b/drivers/clk/shmobile/Makefile
new file mode 100644
index 0000000..d0a9034
--- /dev/null
+++ b/drivers/clk/shmobile/Makefile
@@ -0,0 +1,5 @@
+obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-gen2.o
+obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o
+
+# for emply built-in.o
+obj-n := dummy
diff --git a/drivers/clk/shmobile/clk-rcar-gen2.c b/drivers/clk/shmobile/clk-rcar-gen2.c
new file mode 100644
index 0000000..a59ec21
--- /dev/null
+++ b/drivers/clk/shmobile/clk-rcar-gen2.c
@@ -0,0 +1,298 @@
+/*
+ * rcar_gen2 Core CPG Clocks
+ *
+ * Copyright (C) 2013 Ideas On Board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
+ *
+ * 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/clkdev.h>
+#include <linux/clk/shmobile.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+
+struct rcar_gen2_cpg {
+ struct clk_onecell_data data;
+ spinlock_t lock;
+ void __iomem *reg;
+};
+
+#define CPG_SDCKCR 0x00000074
+#define CPG_PLL0CR 0x000000d8
+#define CPG_FRQCRC 0x000000e0
+#define CPG_FRQCRC_ZFC_MASK (0x1f << 8)
+#define CPG_FRQCRC_ZFC_SHIFT 8
+
+/* -----------------------------------------------------------------------------
+ * Z Clock
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable only ensures that parents are enabled
+ * rate - rate is adjustable. clk->rate = parent->rate * mult / 32
+ * parent - fixed parent. No clk_set_parent support
+ */
+
+struct cpg_z_clk {
+ struct clk_hw hw;
+ void __iomem *reg;
+};
+
+#define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw)
+
+static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct cpg_z_clk *zclk = to_z_clk(hw);
+ unsigned int mult;
+ unsigned int val;
+
+ val = (clk_readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK)
+ >> CPG_FRQCRC_ZFC_SHIFT;
+ mult = 32 - val;
+
+ return div_u64((u64)parent_rate * mult, 32);
+}
+
+static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned long prate = *parent_rate;
+ unsigned int mult;
+
+ if (!prate)
+ prate = 1;
+
+ mult = div_u64((u64)rate * 32, prate);
+ mult = clamp(mult, 1U, 32U);
+
+ return *parent_rate / 32 * mult;
+}
+
+static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct cpg_z_clk *zclk = to_z_clk(hw);
+ unsigned int mult;
+ u32 val;
+
+ mult = div_u64((u64)rate * 32, parent_rate);
+ mult = clamp(mult, 1U, 32U);
+
+ val = clk_readl(zclk->reg);
+ val &= ~CPG_FRQCRC_ZFC_MASK;
+ val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;
+ clk_writel(val, zclk->reg);
+
+ return 0;
+}
+
+static const struct clk_ops cpg_z_clk_ops = {
+ .recalc_rate = cpg_z_clk_recalc_rate,
+ .round_rate = cpg_z_clk_round_rate,
+ .set_rate = cpg_z_clk_set_rate,
+};
+
+static struct clk * __init cpg_z_clk_register(struct rcar_gen2_cpg *cpg)
+{
+ static const char *parent_name = "pll0";
+ struct clk_init_data init;
+ struct cpg_z_clk *zclk;
+ struct clk *clk;
+
+ zclk = kzalloc(sizeof(*zclk), GFP_KERNEL);
+ if (!zclk)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = "z";
+ init.ops = &cpg_z_clk_ops;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ zclk->reg = cpg->reg + CPG_FRQCRC;
+ zclk->hw.init = &init;
+
+ clk = clk_register(NULL, &zclk->hw);
+ if (IS_ERR(clk))
+ kfree(zclk);
+
+ return clk;
+}
+
+/* -----------------------------------------------------------------------------
+ * CPG Clock Data
+ */
+
+/*
+ * MD EXTAL PLL0 PLL1 PLL3
+ * 14 13 19 (MHz) *1 *1
+ *---------------------------------------------------
+ * 0 0 0 15 x 1 x172/2 x208/2 x106
+ * 0 0 1 15 x 1 x172/2 x208/2 x88
+ * 0 1 0 20 x 1 x130/2 x156/2 x80
+ * 0 1 1 20 x 1 x130/2 x156/2 x66
+ * 1 0 0 26 / 2 x200/2 x240/2 x122
+ * 1 0 1 26 / 2 x200/2 x240/2 x102
+ * 1 1 0 30 / 2 x172/2 x208/2 x106
+ * 1 1 1 30 / 2 x172/2 x208/2 x88
+ *
+ * *1 : Table 7.6 indicates VCO ouput (PLLx = VCO/2)
+ */
+#define CPG_PLL_CONFIG_INDEX(md) ((((md) & BIT(14)) >> 12) | \
+ (((md) & BIT(13)) >> 12) | \
+ (((md) & BIT(19)) >> 19))
+struct cpg_pll_config {
+ unsigned int extal_div;
+ unsigned int pll1_mult;
+ unsigned int pll3_mult;
+};
+
+static const struct cpg_pll_config cpg_pll_configs[8] __initconst = {
+ { 1, 208, 106 }, { 1, 208, 88 }, { 1, 156, 80 }, { 1, 156, 66 },
+ { 2, 240, 122 }, { 2, 240, 102 }, { 2, 208, 106 }, { 2, 208, 88 },
+};
+
+/* SDHI divisors */
+static const struct clk_div_table cpg_sdh_div_table[] = {
+ { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 },
+ { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 },
+ { 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 },
+};
+
+static const struct clk_div_table cpg_sd01_div_table[] = {
+ { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
+ { 10, 36 }, { 11, 48 }, { 12, 10 }, { 0, 0 },
+};
+
+/* -----------------------------------------------------------------------------
+ * Initialization
+ */
+
+static u32 cpg_mode __initdata;
+
+static struct clk * __init
+rcar_gen2_cpg_register_clock(struct device_node *np, struct rcar_gen2_cpg *cpg,
+ const struct cpg_pll_config *config,
+ const char *name)
+{
+ const struct clk_div_table *table = NULL;
+ const char *parent_name = "main";
+ unsigned int shift;
+ unsigned int mult = 1;
+ unsigned int div = 1;
+
+ if (!strcmp(name, "main")) {
+ parent_name = of_clk_get_parent_name(np, 0);
+ div = config->extal_div;
+ } else if (!strcmp(name, "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.
+ */
+ u32 value = clk_readl(cpg->reg + CPG_PLL0CR);
+ mult = ((value >> 24) & ((1 << 7) - 1)) + 1;
+ } else if (!strcmp(name, "pll1")) {
+ mult = config->pll1_mult / 2;
+ } else if (!strcmp(name, "pll3")) {
+ mult = config->pll3_mult;
+ } else if (!strcmp(name, "lb")) {
+ div = cpg_mode & BIT(18) ? 36 : 24;
+ } else if (!strcmp(name, "qspi")) {
+ div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2)
+ ? 16 : 20;
+ } else if (!strcmp(name, "sdh")) {
+ table = cpg_sdh_div_table;
+ shift = 8;
+ } else if (!strcmp(name, "sd0")) {
+ table = cpg_sd01_div_table;
+ shift = 4;
+ } else if (!strcmp(name, "sd1")) {
+ table = cpg_sd01_div_table;
+ shift = 0;
+ } else if (!strcmp(name, "z")) {
+ return cpg_z_clk_register(cpg);
+ } else {
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!table)
+ return clk_register_fixed_factor(NULL, name, parent_name, 0,
+ mult, div);
+ else
+ return clk_register_divider_table(NULL, name, parent_name, 0,
+ cpg->reg + CPG_SDCKCR, shift,
+ 4, 0, table, &cpg->lock);
+}
+
+static void __init rcar_gen2_cpg_clocks_init(struct device_node *np)
+{
+ const struct cpg_pll_config *config;
+ struct rcar_gen2_cpg *cpg;
+ struct clk **clks;
+ unsigned int i;
+ int num_clks;
+
+ num_clks = of_property_count_strings(np, "clock-output-names");
+ if (num_clks < 0) {
+ pr_err("%s: failed to count clocks\n", __func__);
+ return;
+ }
+
+ cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
+ clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
+ if (cpg == NULL || clks == NULL) {
+ /* We're leaking memory on purpose, there's no point in cleaning
+ * up as the system won't boot anyway.
+ */
+ pr_err("%s: failed to allocate cpg\n", __func__);
+ return;
+ }
+
+ spin_lock_init(&cpg->lock);
+
+ cpg->data.clks = clks;
+ cpg->data.clk_num = num_clks;
+
+ cpg->reg = of_iomap(np, 0);
+ if (WARN_ON(cpg->reg == NULL))
+ return;
+
+ config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)];
+
+ for (i = 0; i < num_clks; ++i) {
+ const char *name;
+ struct clk *clk;
+
+ of_property_read_string_index(np, "clock-output-names", i,
+ &name);
+
+ clk = rcar_gen2_cpg_register_clock(np, cpg, config, name);
+ if (IS_ERR(clk))
+ pr_err("%s: failed to register %s %s clock (%ld)\n",
+ __func__, np->name, name, PTR_ERR(clk));
+ else
+ cpg->data.clks[i] = clk;
+ }
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
+}
+CLK_OF_DECLARE(rcar_gen2_cpg_clks, "renesas,rcar-gen2-cpg-clocks",
+ rcar_gen2_cpg_clocks_init);
+
+void __init rcar_gen2_clocks_init(u32 mode)
+{
+ cpg_mode = mode;
+
+ of_clk_init(NULL);
+}
diff --git a/include/linux/clk/shmobile.h b/include/linux/clk/shmobile.h
new file mode 100644
index 0000000..f9bf080
--- /dev/null
+++ b/include/linux/clk/shmobile.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright 2013 Ideas On Board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_CLK_SHMOBILE_H_
+#define __LINUX_CLK_SHMOBILE_H_
+
+#include <linux/types.h>
+
+void rcar_gen2_clocks_init(u32 mode);
+
+#endif
--
1.8.3.2
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