diff options
author | Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | 2016-11-09 00:17:25 +0300 |
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committer | Geert Uytterhoeven <geert+renesas@glider.be> | 2016-11-10 17:29:25 +0300 |
commit | 468389357480f21febb0edfd1482d0fc8f885808 (patch) | |
tree | b8afd677a39087925d399cff493655dbd1d6eb33 /drivers/clk | |
parent | 0a30284b9fe19780d4587e74578e460469d88706 (diff) | |
download | linux-468389357480f21febb0edfd1482d0fc8f885808.tar.xz |
clk: renesas: cpg-mssr: Add common R-Car Gen2 support
Add the common R-Car Gen2 (and RZ/G) Clock Pulse Generator / Module
Standby and Software Reset support code, using the CPG/MSSR driver
core.
Based on the proof-of-concept R8A7791 CPG/MSSR patch by Geert
Uytterhoeven <geert+renesas@glider.be>.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/renesas/rcar-gen2-cpg.c | 371 | ||||
-rw-r--r-- | drivers/clk/renesas/rcar-gen2-cpg.h | 43 |
2 files changed, 414 insertions, 0 deletions
diff --git a/drivers/clk/renesas/rcar-gen2-cpg.c b/drivers/clk/renesas/rcar-gen2-cpg.c new file mode 100644 index 000000000000..123b1e622179 --- /dev/null +++ b/drivers/clk/renesas/rcar-gen2-cpg.c @@ -0,0 +1,371 @@ +/* + * R-Car Gen2 Clock Pulse Generator + * + * Copyright (C) 2016 Cogent Embedded Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/bug.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/slab.h> + +#include "renesas-cpg-mssr.h" +#include "rcar-gen2-cpg.h" + +#define CPG_FRQCRB 0x0004 +#define CPG_FRQCRB_KICK BIT(31) +#define CPG_SDCKCR 0x0074 +#define CPG_PLL0CR 0x00d8 +#define CPG_PLL0CR_STC_SHIFT 24 +#define CPG_PLL0CR_STC_MASK (0x7f << CPG_PLL0CR_STC_SHIFT) +#define CPG_FRQCRC 0x00e0 +#define CPG_FRQCRC_ZFC_SHIFT 8 +#define CPG_FRQCRC_ZFC_MASK (0x1f << CPG_FRQCRC_ZFC_SHIFT) +#define CPG_ADSPCKCR 0x025c +#define CPG_RCANCKCR 0x0270 + +static spinlock_t cpg_lock; + +/* + * 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 = (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 (readl(zclk->kick_reg) & CPG_FRQCRB_KICK) + return -EBUSY; + + val = readl(zclk->reg); + val &= ~CPG_FRQCRC_ZFC_MASK; + val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT; + writel(val, zclk->reg); + + /* + * Set KICK bit in FRQCRB to update hardware setting and wait for + * clock change completion. + */ + kick = readl(zclk->kick_reg); + kick |= CPG_FRQCRB_KICK; + 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 dependent on 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 (!(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(const char *name, + const char *parent_name, + void __iomem *base) +{ + 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 = name; + init.ops = &cpg_z_clk_ops; + init.flags = 0; + init.parent_names = &parent_name; + init.num_parents = 1; + + zclk->reg = base + CPG_FRQCRC; + zclk->kick_reg = base + CPG_FRQCRB; + zclk->hw.init = &init; + + clk = clk_register(NULL, &zclk->hw); + if (IS_ERR(clk)) + kfree(zclk); + + return clk; +} + +static struct clk * __init cpg_rcan_clk_register(const char *name, + const char *parent_name, + void __iomem *base) +{ + struct clk_fixed_factor *fixed; + struct clk_gate *gate; + struct clk *clk; + + fixed = kzalloc(sizeof(*fixed), GFP_KERNEL); + if (!fixed) + return ERR_PTR(-ENOMEM); + + fixed->mult = 1; + fixed->div = 6; + + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) { + kfree(fixed); + return ERR_PTR(-ENOMEM); + } + + gate->reg = base + CPG_RCANCKCR; + gate->bit_idx = 8; + gate->flags = CLK_GATE_SET_TO_DISABLE; + gate->lock = &cpg_lock; + + clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL, + &fixed->hw, &clk_fixed_factor_ops, + &gate->hw, &clk_gate_ops, 0); + if (IS_ERR(clk)) { + kfree(gate); + kfree(fixed); + } + + return clk; +} + +/* ADSP divisors */ +static const struct clk_div_table cpg_adsp_div_table[] = { + { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 }, + { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 }, + { 10, 36 }, { 11, 48 }, { 0, 0 }, +}; + +static struct clk * __init cpg_adsp_clk_register(const char *name, + const char *parent_name, + void __iomem *base) +{ + struct clk_divider *div; + struct clk_gate *gate; + struct clk *clk; + + div = kzalloc(sizeof(*div), GFP_KERNEL); + if (!div) + return ERR_PTR(-ENOMEM); + + div->reg = base + CPG_ADSPCKCR; + div->width = 4; + div->table = cpg_adsp_div_table; + div->lock = &cpg_lock; + + gate = kzalloc(sizeof(*gate), GFP_KERNEL); + if (!gate) { + kfree(div); + return ERR_PTR(-ENOMEM); + } + + gate->reg = base + CPG_ADSPCKCR; + gate->bit_idx = 8; + gate->flags = CLK_GATE_SET_TO_DISABLE; + gate->lock = &cpg_lock; + + clk = clk_register_composite(NULL, name, &parent_name, 1, NULL, NULL, + &div->hw, &clk_divider_ops, + &gate->hw, &clk_gate_ops, 0); + if (IS_ERR(clk)) { + kfree(gate); + kfree(div); + } + + return clk; +} + +/* 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[] = { + { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 }, + { 8, 24 }, { 10, 36 }, { 11, 48 }, { 12, 10 }, + { 0, 0 }, +}; + +static const struct rcar_gen2_cpg_pll_config *cpg_pll_config __initdata; +static unsigned int cpg_pll0_div __initdata; +static u32 cpg_mode __initdata; + +struct clk * __init rcar_gen2_cpg_clk_register(struct device *dev, + const struct cpg_core_clk *core, + const struct cpg_mssr_info *info, + struct clk **clks, + void __iomem *base) +{ + const struct clk_div_table *table = NULL; + const struct clk *parent; + const char *parent_name; + unsigned int mult = 1; + unsigned int div = 1; + unsigned int shift; + + parent = clks[core->parent]; + if (IS_ERR(parent)) + return ERR_CAST(parent); + + parent_name = __clk_get_name(parent); + + switch (core->type) { + /* R-Car Gen2 */ + case CLK_TYPE_GEN2_MAIN: + div = cpg_pll_config->extal_div; + break; + + case CLK_TYPE_GEN2_PLL0: + /* + * PLL0 is a configurable multiplier clock except on R-Car + * V2H/E2. Register the PLL0 clock 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. + */ + mult = cpg_pll_config->pll0_mult; + div = cpg_pll0_div; + if (!mult) { + u32 pll0cr = readl(base + CPG_PLL0CR); + + mult = (((pll0cr & CPG_PLL0CR_STC_MASK) >> + CPG_PLL0CR_STC_SHIFT) + 1) * 2; + } + break; + + case CLK_TYPE_GEN2_PLL1: + mult = cpg_pll_config->pll1_mult / 2; + break; + + case CLK_TYPE_GEN2_PLL3: + mult = cpg_pll_config->pll3_mult; + break; + + case CLK_TYPE_GEN2_Z: + return cpg_z_clk_register(core->name, parent_name, base); + + case CLK_TYPE_GEN2_LB: + div = cpg_mode & BIT(18) ? 36 : 24; + break; + + case CLK_TYPE_GEN2_ADSP: + return cpg_adsp_clk_register(core->name, parent_name, base); + + case CLK_TYPE_GEN2_SDH: + table = cpg_sdh_div_table; + shift = 8; + break; + + case CLK_TYPE_GEN2_SD0: + table = cpg_sd01_div_table; + shift = 4; + break; + + case CLK_TYPE_GEN2_SD1: + table = cpg_sd01_div_table; + shift = 0; + break; + + case CLK_TYPE_GEN2_QSPI: + div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2) ? + 8 : 10; + break; + + case CLK_TYPE_GEN2_RCAN: + return cpg_rcan_clk_register(core->name, parent_name, base); + + default: + return ERR_PTR(-EINVAL); + } + + if (!table) + return clk_register_fixed_factor(NULL, core->name, parent_name, + 0, mult, div); + else + return clk_register_divider_table(NULL, core->name, + parent_name, 0, + base + CPG_SDCKCR, shift, 4, + 0, table, &cpg_lock); +} + +int __init rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config, + unsigned int pll0_div, u32 mode) +{ + cpg_pll_config = config; + cpg_pll0_div = pll0_div; + cpg_mode = mode; + + spin_lock_init(&cpg_lock); + + return 0; +} diff --git a/drivers/clk/renesas/rcar-gen2-cpg.h b/drivers/clk/renesas/rcar-gen2-cpg.h new file mode 100644 index 000000000000..9eba07ff8b11 --- /dev/null +++ b/drivers/clk/renesas/rcar-gen2-cpg.h @@ -0,0 +1,43 @@ +/* + * R-Car Gen2 Clock Pulse Generator + * + * Copyright (C) 2016 Cogent Embedded Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation; version 2 of the License. + */ + +#ifndef __CLK_RENESAS_RCAR_GEN2_CPG_H__ +#define __CLK_RENESAS_RCAR_GEN2_CPG_H__ + +enum rcar_gen2_clk_types { + CLK_TYPE_GEN2_MAIN = CLK_TYPE_CUSTOM, + CLK_TYPE_GEN2_PLL0, + CLK_TYPE_GEN2_PLL1, + CLK_TYPE_GEN2_PLL3, + CLK_TYPE_GEN2_Z, + CLK_TYPE_GEN2_LB, + CLK_TYPE_GEN2_ADSP, + CLK_TYPE_GEN2_SDH, + CLK_TYPE_GEN2_SD0, + CLK_TYPE_GEN2_SD1, + CLK_TYPE_GEN2_QSPI, + CLK_TYPE_GEN2_RCAN, +}; + +struct rcar_gen2_cpg_pll_config { + unsigned int extal_div; + unsigned int pll1_mult; + unsigned int pll3_mult; + unsigned int pll0_mult; /* leave as zero if PLL0CR exists */ +}; + +struct clk *rcar_gen2_cpg_clk_register(struct device *dev, + const struct cpg_core_clk *core, + const struct cpg_mssr_info *info, + struct clk **clks, void __iomem *base); +int rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config, + unsigned int pll0_div, u32 mode); + +#endif |