diff options
Diffstat (limited to 'drivers/clk/renesas/clk-r8a7778.c')
-rw-r--r-- | drivers/clk/renesas/clk-r8a7778.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/drivers/clk/renesas/clk-r8a7778.c b/drivers/clk/renesas/clk-r8a7778.c new file mode 100644 index 000000000..886a8380e --- /dev/null +++ b/drivers/clk/renesas/clk-r8a7778.c @@ -0,0 +1,145 @@ +/* + * r8a7778 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/of_address.h> +#include <linux/slab.h> +#include <linux/soc/renesas/rcar-rst.h> + +struct r8a7778_cpg { + struct clk_onecell_data data; + spinlock_t lock; + void __iomem *reg; +}; + +/* PLL multipliers per bits 11, 12, and 18 of MODEMR */ +static const struct { + unsigned long plla_mult; + unsigned long pllb_mult; +} r8a7778_rates[] __initconst = { + [0] = { 21, 21 }, + [1] = { 24, 24 }, + [2] = { 28, 28 }, + [3] = { 32, 32 }, + [5] = { 24, 21 }, + [6] = { 28, 21 }, + [7] = { 32, 24 }, +}; + +/* Clock dividers per bits 1 and 2 of MODEMR */ +static const struct { + const char *name; + unsigned int div[4]; +} r8a7778_divs[6] __initconst = { + { "b", { 12, 12, 16, 18 } }, + { "out", { 12, 12, 16, 18 } }, + { "p", { 16, 12, 16, 12 } }, + { "s", { 4, 3, 4, 3 } }, + { "s1", { 8, 6, 8, 6 } }, +}; + +static u32 cpg_mode_rates __initdata; +static u32 cpg_mode_divs __initdata; + +static struct clk * __init +r8a7778_cpg_register_clock(struct device_node *np, struct r8a7778_cpg *cpg, + const char *name) +{ + if (!strcmp(name, "plla")) { + return clk_register_fixed_factor(NULL, "plla", + of_clk_get_parent_name(np, 0), 0, + r8a7778_rates[cpg_mode_rates].plla_mult, 1); + } else if (!strcmp(name, "pllb")) { + return clk_register_fixed_factor(NULL, "pllb", + of_clk_get_parent_name(np, 0), 0, + r8a7778_rates[cpg_mode_rates].pllb_mult, 1); + } else { + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(r8a7778_divs); i++) { + if (!strcmp(name, r8a7778_divs[i].name)) { + return clk_register_fixed_factor(NULL, + r8a7778_divs[i].name, + "plla", 0, 1, + r8a7778_divs[i].div[cpg_mode_divs]); + } + } + } + + return ERR_PTR(-EINVAL); +} + + +static void __init r8a7778_cpg_clocks_init(struct device_node *np) +{ + struct r8a7778_cpg *cpg; + struct clk **clks; + unsigned int i; + int num_clks; + u32 mode; + + if (rcar_rst_read_mode_pins(&mode)) + return; + + BUG_ON(!(mode & BIT(19))); + + cpg_mode_rates = (!!(mode & BIT(18)) << 2) | + (!!(mode & BIT(12)) << 1) | + (!!(mode & BIT(11))); + cpg_mode_divs = (!!(mode & BIT(2)) << 1) | + (!!(mode & BIT(1))); + + 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 = r8a7778_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); + + cpg_mstp_add_clk_domain(np); +} + +CLK_OF_DECLARE(r8a7778_cpg_clks, "renesas,r8a7778-cpg-clocks", + r8a7778_cpg_clocks_init); |