[PATCH v4] clk: shmobile: Add R8A7740-specific clock support
Ulrich Hecht
ulrich.hecht at gmail.com
Thu May 22 07:23:43 PDT 2014
Driver for the R8A7740's clocks that are too specific to be supported by a
generic driver.
Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas at gmail.com>
---
Changes since v3:
- removed excess element in struct initializer
- use of_clk_get_parent_name() instead of hardcoding extal2
- fixed wrong parent index for extalr
- reformatted register addresses
Changes since v2:
- added missing clock extal2
- removed redundant divider mask
Changes since v1:
- reshuffled to include DT bindings and Makefile changes
.../bindings/clock/renesas,r8a7740-cpg-clocks.txt | 39 ++++
drivers/clk/shmobile/Makefile | 1 +
drivers/clk/shmobile/clk-r8a7740.c | 199 +++++++++++++++++++++
3 files changed, 239 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/renesas,r8a7740-cpg-clocks.txt
create mode 100644 drivers/clk/shmobile/clk-r8a7740.c
diff --git a/Documentation/devicetree/bindings/clock/renesas,r8a7740-cpg-clocks.txt b/Documentation/devicetree/bindings/clock/renesas,r8a7740-cpg-clocks.txt
new file mode 100644
index 0000000..8432e00
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/renesas,r8a7740-cpg-clocks.txt
@@ -0,0 +1,39 @@
+* Renesas R8A7740 Clock Pulse Generator (CPG)
+
+The CPG generates core clocks for the R8A7740 SoC. It includes three PLLs
+and several fixed ratio and variable ratio dividers.
+
+Required Properties:
+
+ - compatible: Must be "renesas,r8a7740-cpg-clocks"
+
+ - reg: Base address and length of the memory resource used by the CPG
+
+ - clocks: Reference to the three parent clocks
+ - #clock-cells: Must be 1
+ - clock-output-names: The names of the clocks. Supported clocks are
+ "system", "pllc0", "pllc1", "pllc2", "r", "usb24s", "i", "zg", "b",
+ "m1", "hp", "hpp", "usbp", "s", "zb", "m3", and "cp".
+
+ - renesas,mode: board-specific settings of the MD_CK* bits
+
+
+Example
+-------
+
+cpg_clocks: cpg_clocks at e6150000 {
+ compatible = "renesas,r8a7740-cpg-clocks";
+ reg = <0xe6150000 0x10000>;
+ clocks = <&extal1_clk>, <&extal2_clk>, <&extalr_clk>;
+ #clock-cells = <1>;
+ clock-output-names = "system", "pllc0", "pllc1",
+ "pllc2", "r",
+ "usb24s",
+ "i", "zg", "b", "m1", "hp",
+ "hpp", "usbp", "s", "zb", "m3",
+ "cp";
+};
+
+&cpg_clocks {
+ renesas,mode = <0x05>;
+};
diff --git a/drivers/clk/shmobile/Makefile b/drivers/clk/shmobile/Makefile
index 5404cb9..20388e8 100644
--- a/drivers/clk/shmobile/Makefile
+++ b/drivers/clk/shmobile/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_ARCH_EMEV2) += clk-emev2.o
obj-$(CONFIG_ARCH_R7S72100) += clk-rz.o
+obj-$(CONFIG_ARCH_R8A7740) += clk-r8a7740.o
obj-$(CONFIG_ARCH_R8A7790) += clk-rcar-gen2.o
obj-$(CONFIG_ARCH_R8A7791) += clk-rcar-gen2.o
obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += clk-div6.o
diff --git a/drivers/clk/shmobile/clk-r8a7740.c b/drivers/clk/shmobile/clk-r8a7740.c
new file mode 100644
index 0000000..1e2eaae
--- /dev/null
+++ b/drivers/clk/shmobile/clk-r8a7740.c
@@ -0,0 +1,199 @@
+/*
+ * r8a7740 Core CPG Clocks
+ *
+ * Copyright (C) 2014 Ulrich Hecht
+ *
+ * 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/of.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+
+struct r8a7740_cpg {
+ struct clk_onecell_data data;
+ spinlock_t lock;
+ void __iomem *reg;
+};
+
+#define CPG_FRQCRA 0x00
+#define CPG_FRQCRB 0x04
+#define CPG_PLLC2CR 0x2c
+#define CPG_USBCKCR 0x8c
+#define CPG_FRQCRC 0xe0
+
+#define CLK_ENABLE_ON_INIT BIT(0)
+
+struct div4_clk {
+ const char *name;
+ unsigned int reg;
+ unsigned int shift;
+ int flags;
+};
+
+static struct div4_clk div4_clks[] = {
+ { "i", CPG_FRQCRA, 20, CLK_ENABLE_ON_INIT },
+ { "zg", CPG_FRQCRA, 16, CLK_ENABLE_ON_INIT },
+ { "b", CPG_FRQCRA, 8, CLK_ENABLE_ON_INIT },
+ { "m1", CPG_FRQCRA, 4, CLK_ENABLE_ON_INIT },
+ { "hp", CPG_FRQCRB, 4, 0 },
+ { "hpp", CPG_FRQCRC, 20, 0 },
+ { "usbp", CPG_FRQCRC, 16, 0 },
+ { "s", CPG_FRQCRC, 12, 0 },
+ { "zb", CPG_FRQCRC, 8, 0 },
+ { "m3", CPG_FRQCRC, 4, 0 },
+ { "cp", CPG_FRQCRC, 0, 0 },
+ { NULL, 0, 0, 0 },
+};
+
+static const struct clk_div_table div4_div_table[] = {
+ { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, { 5, 12 },
+ { 6, 16 }, { 7, 18 }, { 8, 24 }, { 9, 32 }, { 10, 36 }, { 11, 48 },
+ { 13, 72 }, { 14, 96 }, { 0, 0 }
+};
+
+static u32 cpg_mode __initdata;
+
+static struct clk * __init
+r8a7740_cpg_register_clock(struct device_node *np, struct r8a7740_cpg *cpg,
+ const char *name)
+{
+ const struct clk_div_table *table = NULL;
+ const char *parent_name;
+ unsigned int shift, reg;
+ unsigned int mult = 1;
+ unsigned int div = 1;
+
+ if (!strcmp(name, "r")) {
+ switch (cpg_mode & (BIT(2) | BIT(1))) {
+ case BIT(1) | BIT(2):
+ /* extal1 */
+ parent_name = of_clk_get_parent_name(np, 0);
+ div = 2048;
+ break;
+ case BIT(2):
+ /* extal1 */
+ parent_name = of_clk_get_parent_name(np, 0);
+ div = 1024;
+ break;
+ default:
+ /* extalr */
+ parent_name = of_clk_get_parent_name(np, 2);
+ break;
+ }
+ } else if (!strcmp(name, "system")) {
+ parent_name = of_clk_get_parent_name(np, 0);
+ if (cpg_mode & BIT(1))
+ div = 2;
+ } else if (!strcmp(name, "pllc0")) {
+ /* PLLC0/1 are configurable multiplier clocks. Register them as
+ * fixed factor clocks 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_FRQCRC);
+ parent_name = "system";
+ mult = ((value >> 24) & 0x7f) + 1;
+ } else if (!strcmp(name, "pllc1")) {
+ u32 value = clk_readl(cpg->reg + CPG_FRQCRA);
+ parent_name = "system";
+ mult = ((value >> 24) & 0x7f) + 1;
+ div = 2;
+ } else if (!strcmp(name, "pllc2")) {
+ u32 value = clk_readl(cpg->reg + CPG_PLLC2CR);
+ parent_name = "system";
+ mult = ((value >> 24) & 0x3f) + 1;
+ } else if (!strcmp(name, "usb24s")) {
+ u32 value = clk_readl(cpg->reg + CPG_USBCKCR);
+ if (value & BIT(7))
+ /* extal2 */
+ parent_name = of_clk_get_parent_name(np, 1);
+ else
+ parent_name = "system";
+ if (!(value & BIT(6)))
+ div = 2;
+ } else {
+ struct div4_clk *c;
+ for (c = div4_clks; c->name; c++) {
+ if (!strcmp(name, c->name)) {
+ parent_name = "pllc1";
+ table = div4_div_table;
+ reg = c->reg;
+ shift = c->shift;
+ break;
+ }
+ }
+ if (!c->name)
+ 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 + reg, shift, 4, 0,
+ table, &cpg->lock);
+ }
+}
+
+static void __init r8a7740_cpg_clocks_init(struct device_node *np)
+{
+ struct r8a7740_cpg *cpg;
+ struct clk **clks;
+ unsigned int i;
+ int num_clks;
+
+ if (of_property_read_u32(np, "renesas,mode", &cpg_mode))
+ pr_warn("%s: missing renesas,mode property\n", __func__);
+
+ 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.
+ */
+ 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;
+
+ 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 = r8a7740_cpg_register_clock(np, cpg, 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(r8a7740_cpg_clks, "renesas,r8a7740-cpg-clocks",
+ r8a7740_cpg_clocks_init);
--
1.8.4.5
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