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path: root/drivers/clk/shmobile/clk-r8a73a4.c
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Diffstat (limited to 'drivers/clk/shmobile/clk-r8a73a4.c')
-rw-r--r--drivers/clk/shmobile/clk-r8a73a4.c241
1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/clk/shmobile/clk-r8a73a4.c b/drivers/clk/shmobile/clk-r8a73a4.c
new file mode 100644
index 000000000000..29b9a0b0012a
--- /dev/null
+++ b/drivers/clk/shmobile/clk-r8a73a4.c
@@ -0,0 +1,241 @@
+/*
+ * r8a73a4 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 r8a73a4_cpg {
+ struct clk_onecell_data data;
+ spinlock_t lock;
+ void __iomem *reg;
+};
+
+#define CPG_CKSCR 0xc0
+#define CPG_FRQCRA 0x00
+#define CPG_FRQCRB 0x04
+#define CPG_FRQCRC 0xe0
+#define CPG_PLL0CR 0xd8
+#define CPG_PLL1CR 0x28
+#define CPG_PLL2CR 0x2c
+#define CPG_PLL2HCR 0xe4
+#define CPG_PLL2SCR 0xf4
+
+#define CLK_ENABLE_ON_INIT BIT(0)
+
+struct div4_clk {
+ const char *name;
+ unsigned int reg;
+ unsigned int shift;
+};
+
+static struct div4_clk div4_clks[] = {
+ { "i", CPG_FRQCRA, 20 },
+ { "m3", CPG_FRQCRA, 12 },
+ { "b", CPG_FRQCRA, 8 },
+ { "m1", CPG_FRQCRA, 4 },
+ { "m2", CPG_FRQCRA, 0 },
+ { "zx", CPG_FRQCRB, 12 },
+ { "zs", CPG_FRQCRB, 8 },
+ { "hp", CPG_FRQCRB, 4 },
+ { NULL, 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 }, { 10, 36 }, { 11, 48 },
+ { 12, 10 }, { 0, 0 }
+};
+
+static struct clk * __init
+r8a73a4_cpg_register_clock(struct device_node *np, struct r8a73a4_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, "main")) {
+ u32 ckscr = clk_readl(cpg->reg + CPG_CKSCR);
+
+ switch ((ckscr >> 28) & 3) {
+ case 0: /* extal1 */
+ parent_name = of_clk_get_parent_name(np, 0);
+ break;
+ case 1: /* extal1 / 2 */
+ parent_name = of_clk_get_parent_name(np, 0);
+ div = 2;
+ break;
+ case 2: /* extal2 */
+ parent_name = of_clk_get_parent_name(np, 1);
+ break;
+ case 3: /* extal2 / 2 */
+ parent_name = of_clk_get_parent_name(np, 1);
+ div = 2;
+ break;
+ }
+ } else if (!strcmp(name, "pll0")) {
+ /* PLL0/1 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_PLL0CR);
+
+ parent_name = "main";
+ mult = ((value >> 24) & 0x7f) + 1;
+ if (value & BIT(20))
+ div = 2;
+ } else if (!strcmp(name, "pll1")) {
+ u32 value = clk_readl(cpg->reg + CPG_PLL1CR);
+
+ parent_name = "main";
+ /* XXX: enable bit? */
+ mult = ((value >> 24) & 0x7f) + 1;
+ if (value & BIT(7))
+ div = 2;
+ } else if (!strncmp(name, "pll2", 4)) {
+ u32 value, cr;
+
+ switch (name[4]) {
+ case 0:
+ cr = CPG_PLL2CR;
+ break;
+ case 's':
+ cr = CPG_PLL2SCR;
+ break;
+ case 'h':
+ cr = CPG_PLL2HCR;
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+ value = clk_readl(cpg->reg + cr);
+ switch ((value >> 5) & 7) {
+ case 0:
+ parent_name = "main";
+ div = 2;
+ break;
+ case 1:
+ parent_name = "extal2";
+ div = 2;
+ break;
+ case 3:
+ parent_name = "extal2";
+ div = 4;
+ break;
+ case 4:
+ parent_name = "main";
+ break;
+ case 5:
+ parent_name = "extal2";
+ break;
+ default:
+ pr_warn("%s: unexpected parent of %s\n", __func__,
+ name);
+ return ERR_PTR(-EINVAL);
+ }
+ /* XXX: enable bit? */
+ mult = ((value >> 24) & 0x7f) + 1;
+ } else if (!strcmp(name, "z") || !strcmp(name, "z2")) {
+ u32 shift = 8;
+
+ parent_name = "pll0";
+ if (name[1] == '2') {
+ div = 2;
+ shift = 0;
+ }
+ div *= 32;
+ mult = 0x20 - ((clk_readl(cpg->reg + CPG_FRQCRC) >> shift)
+ & 0x1f);
+ } else {
+ struct div4_clk *c;
+
+ for (c = div4_clks; c->name; c++) {
+ if (!strcmp(name, c->name))
+ break;
+ }
+ if (!c->name)
+ return ERR_PTR(-EINVAL);
+
+ parent_name = "pll1";
+ table = div4_div_table;
+ reg = c->reg;
+ shift = c->shift;
+ }
+
+ 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 r8a73a4_cpg_clocks_init(struct device_node *np)
+{
+ struct r8a73a4_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 = kcalloc(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 = r8a73a4_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(r8a73a4_cpg_clks, "renesas,r8a73a4-cpg-clocks",
+ r8a73a4_cpg_clocks_init);