diff options
Diffstat (limited to 'drivers/clk/shmobile/clk-rcar-gen2.c')
| -rw-r--r-- | drivers/clk/shmobile/clk-rcar-gen2.c | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/clk/shmobile/clk-rcar-gen2.c b/drivers/clk/shmobile/clk-rcar-gen2.c new file mode 100644 index 000000000000..99c27b1c625b --- /dev/null +++ b/drivers/clk/shmobile/clk-rcar-gen2.c @@ -0,0 +1,338 @@ +/* + * rcar_gen2 Core CPG Clocks + * + * Copyright (C) 2013 Ideas On Board SPRL + * + * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.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/clkdev.h> +#include <linux/clk/shmobile.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/math64.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/spinlock.h> + +struct rcar_gen2_cpg { + struct clk_onecell_data data; + spinlock_t lock; + void __iomem *reg; +}; + +#define CPG_FRQCRB 0x00000004 +#define CPG_FRQCRB_KICK BIT(31) +#define CPG_SDCKCR 0x00000074 +#define CPG_PLL0CR 0x000000d8 +#define CPG_FRQCRC 0x000000e0 +#define CPG_FRQCRC_ZFC_MASK (0x1f << 8) +#define CPG_FRQCRC_ZFC_SHIFT 8 + +/* ----------------------------------------------------------------------------- + * Z Clock + * + * Traits of this clock: + * prepare - clk_prepare only ensures that parents are prepared + * enable - clk_enable only ensures that parents are enabled + * rate - rate is adjustable. clk->rate = parent->rate * mult / 32 + * parent - fixed parent. No clk_set_parent support + */ + +struct cpg_z_clk { + struct clk_hw hw; + void __iomem *reg; + void __iomem *kick_reg; +}; + +#define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw) + +static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct cpg_z_clk *zclk = to_z_clk(hw); + unsigned int mult; + unsigned int val; + + val = (clk_readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK) + >> CPG_FRQCRC_ZFC_SHIFT; + mult = 32 - val; + + return div_u64((u64)parent_rate * mult, 32); +} + +static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned long prate = *parent_rate; + unsigned int mult; + + if (!prate) + prate = 1; + + mult = div_u64((u64)rate * 32, prate); + mult = clamp(mult, 1U, 32U); + + return *parent_rate / 32 * mult; +} + +static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct cpg_z_clk *zclk = to_z_clk(hw); + unsigned int mult; + u32 val, kick; + unsigned int i; + + mult = div_u64((u64)rate * 32, parent_rate); + mult = clamp(mult, 1U, 32U); + + if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK) + return -EBUSY; + + val = clk_readl(zclk->reg); + val &= ~CPG_FRQCRC_ZFC_MASK; + val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT; + clk_writel(val, zclk->reg); + + /* + * Set KICK bit in FRQCRB to update hardware setting and wait for + * clock change completion. + */ + kick = clk_readl(zclk->kick_reg); + kick |= CPG_FRQCRB_KICK; + clk_writel(kick, zclk->kick_reg); + + /* + * Note: There is no HW information about the worst case latency. + * + * Using experimental measurements, it seems that no more than + * ~10 iterations are needed, independently of the CPU rate. + * Since this value might be dependant of external xtal rate, pll1 + * rate or even the other emulation clocks rate, use 1000 as a + * "super" safe value. + */ + for (i = 1000; i; i--) { + if (!(clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK)) + return 0; + + cpu_relax(); + } + + return -ETIMEDOUT; +} + +static const struct clk_ops cpg_z_clk_ops = { + .recalc_rate = cpg_z_clk_recalc_rate, + .round_rate = cpg_z_clk_round_rate, + .set_rate = cpg_z_clk_set_rate, +}; + +static struct clk * __init cpg_z_clk_register(struct rcar_gen2_cpg *cpg) +{ + static const char *parent_name = "pll0"; + struct clk_init_data init; + struct cpg_z_clk *zclk; + struct clk *clk; + + zclk = kzalloc(sizeof(*zclk), GFP_KERNEL); + if (!zclk) + return ERR_PTR(-ENOMEM); + + init.name = "z"; + init.ops = &cpg_z_clk_ops; + init.flags = 0; + init.parent_names = &parent_name; + init.num_parents = 1; + + zclk->reg = cpg->reg + CPG_FRQCRC; + zclk->kick_reg = cpg->reg + CPG_FRQCRB; + zclk->hw.init = &init; + + clk = clk_register(NULL, &zclk->hw); + if (IS_ERR(clk)) + kfree(zclk); + + return clk; +} + +/* ----------------------------------------------------------------------------- + * CPG Clock Data + */ + +/* + * MD EXTAL PLL0 PLL1 PLL3 + * 14 13 19 (MHz) *1 *1 + *--------------------------------------------------- + * 0 0 0 15 x 1 x172/2 x208/2 x106 + * 0 0 1 15 x 1 x172/2 x208/2 x88 + * 0 1 0 20 x 1 x130/2 x156/2 x80 + * 0 1 1 20 x 1 x130/2 x156/2 x66 + * 1 0 0 26 / 2 x200/2 x240/2 x122 + * 1 0 1 26 / 2 x200/2 x240/2 x102 + * 1 1 0 30 / 2 x172/2 x208/2 x106 + * 1 1 1 30 / 2 x172/2 x208/2 x88 + * + * *1 : Table 7.6 indicates VCO ouput (PLLx = VCO/2) + */ +#define CPG_PLL_CONFIG_INDEX(md) ((((md) & BIT(14)) >> 12) | \ + (((md) & BIT(13)) >> 12) | \ + (((md) & BIT(19)) >> 19)) +struct cpg_pll_config { + unsigned int extal_div; + unsigned int pll1_mult; + unsigned int pll3_mult; +}; + +static const struct cpg_pll_config cpg_pll_configs[8] __initconst = { + { 1, 208, 106 }, { 1, 208, 88 }, { 1, 156, 80 }, { 1, 156, 66 }, + { 2, 240, 122 }, { 2, 240, 102 }, { 2, 208, 106 }, { 2, 208, 88 }, +}; + +/* SDHI divisors */ +static const struct clk_div_table cpg_sdh_div_table[] = { + { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 }, + { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 }, + { 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 }, +}; + +static const struct clk_div_table cpg_sd01_div_table[] = { + { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 }, + { 10, 36 }, { 11, 48 }, { 12, 10 }, { 0, 0 }, +}; + +/* ----------------------------------------------------------------------------- + * Initialization + */ + +static u32 cpg_mode __initdata; + +static struct clk * __init +rcar_gen2_cpg_register_clock(struct device_node *np, struct rcar_gen2_cpg *cpg, + const struct cpg_pll_config *config, + const char *name) +{ + const struct clk_div_table *table = NULL; + const char *parent_name; + unsigned int shift; + unsigned int mult = 1; + unsigned int div = 1; + + if (!strcmp(name, "main")) { + parent_name = of_clk_get_parent_name(np, 0); + div = config->extal_div; + } else if (!strcmp(name, "pll0")) { + /* PLL0 is a configurable multiplier clock. Register it as a + * fixed factor clock 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) & ((1 << 7) - 1)) + 1; + } else if (!strcmp(name, "pll1")) { + parent_name = "main"; + mult = config->pll1_mult / 2; + } else if (!strcmp(name, "pll3")) { + parent_name = "main"; + mult = config->pll3_mult; + } else if (!strcmp(name, "lb")) { + parent_name = "pll1_div2"; + div = cpg_mode & BIT(18) ? 36 : 24; + } else if (!strcmp(name, "qspi")) { + parent_name = "pll1_div2"; + div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2) + ? 8 : 10; + } else if (!strcmp(name, "sdh")) { + parent_name = "pll1_div2"; + table = cpg_sdh_div_table; + shift = 8; + } else if (!strcmp(name, "sd0")) { + parent_name = "pll1_div2"; + table = cpg_sd01_div_table; + shift = 4; + } else if (!strcmp(name, "sd1")) { + parent_name = "pll1_div2"; + table = cpg_sd01_div_table; + shift = 0; + } else if (!strcmp(name, "z")) { + return cpg_z_clk_register(cpg); + } else { + 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 + CPG_SDCKCR, shift, + 4, 0, table, &cpg->lock); +} + +static void __init rcar_gen2_cpg_clocks_init(struct device_node *np) +{ + const struct cpg_pll_config *config; + struct rcar_gen2_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 = 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. + */ + pr_err("%s: failed to allocate cpg\n", __func__); + 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; + + config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)]; + + 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 = rcar_gen2_cpg_register_clock(np, cpg, config, 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(rcar_gen2_cpg_clks, "renesas,rcar-gen2-cpg-clocks", + rcar_gen2_cpg_clocks_init); + +void __init rcar_gen2_clocks_init(u32 mode) +{ + cpg_mode = mode; + + of_clk_init(NULL); +} |