diff options
Diffstat (limited to 'drivers/clk/shmobile/clk-rz.c')
| -rw-r--r-- | drivers/clk/shmobile/clk-rz.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/clk/shmobile/clk-rz.c b/drivers/clk/shmobile/clk-rz.c new file mode 100644 index 000000000000..7e68e8630962 --- /dev/null +++ b/drivers/clk/shmobile/clk-rz.c @@ -0,0 +1,103 @@ +/* + * rz Core CPG Clocks + * + * Copyright (C) 2013 Ideas On Board SPRL + * Copyright (C) 2014 Wolfram Sang, Sang Engineering <wsa@sang-engineering.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/init.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/slab.h> + +struct rz_cpg { + struct clk_onecell_data data; + void __iomem *reg; +}; + +#define CPG_FRQCR 0x10 +#define CPG_FRQCR2 0x14 + +/* ----------------------------------------------------------------------------- + * Initialization + */ + +static struct clk * __init +rz_cpg_register_clock(struct device_node *np, struct rz_cpg *cpg, const char *name) +{ + u32 val; + unsigned mult; + static const unsigned frqcr_tab[4] = { 3, 2, 0, 1 }; + + if (strcmp(name, "pll") == 0) { + /* FIXME: cpg_mode should be read from GPIO. But no GPIO support yet */ + unsigned cpg_mode = 0; /* hardcoded to EXTAL for now */ + const char *parent_name = of_clk_get_parent_name(np, cpg_mode); + + mult = cpg_mode ? (32 / 4) : 30; + + return clk_register_fixed_factor(NULL, name, parent_name, 0, mult, 1); + } + + /* If mapping regs failed, skip non-pll clocks. System will boot anyhow */ + if (!cpg->reg) + return ERR_PTR(-ENXIO); + + /* FIXME:"i" and "g" are variable clocks with non-integer dividers (e.g. 2/3) + * and the constraint that always g <= i. To get the rz platform started, + * let them run at fixed current speed and implement the details later. + */ + if (strcmp(name, "i") == 0) + val = (clk_readl(cpg->reg + CPG_FRQCR) >> 8) & 3; + else if (strcmp(name, "g") == 0) + val = clk_readl(cpg->reg + CPG_FRQCR2) & 3; + else + return ERR_PTR(-EINVAL); + + mult = frqcr_tab[val]; + return clk_register_fixed_factor(NULL, name, "pll", 0, mult, 3); +} + +static void __init rz_cpg_clocks_init(struct device_node *np) +{ + struct rz_cpg *cpg; + struct clk **clks; + unsigned i; + int num_clks; + + num_clks = of_property_count_strings(np, "clock-output-names"); + if (WARN(num_clks <= 0, "can't count CPG clocks\n")) + return; + + cpg = kzalloc(sizeof(*cpg), GFP_KERNEL); + clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL); + BUG_ON(!cpg || !clks); + + cpg->data.clks = clks; + cpg->data.clk_num = num_clks; + + cpg->reg = of_iomap(np, 0); + + 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 = rz_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(rz_cpg_clks, "renesas,rz-cpg-clocks", rz_cpg_clocks_init); |