diff options
Diffstat (limited to 'drivers/clk/renesas/clk-r8a73a4.c')
| -rw-r--r-- | drivers/clk/renesas/clk-r8a73a4.c | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/clk/renesas/clk-r8a73a4.c b/drivers/clk/renesas/clk-r8a73a4.c new file mode 100644 index 000000000000..28d204bb659e --- /dev/null +++ b/drivers/clk/renesas/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/clk/renesas.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/slab.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); |