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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/renesas/rcar-gen4-cpg.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/drivers/clk/renesas/rcar-gen4-cpg.c b/drivers/clk/renesas/rcar-gen4-cpg.c new file mode 100644 index 000000000..e27832e51 --- /dev/null +++ b/drivers/clk/renesas/rcar-gen4-cpg.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * R-Car Gen4 Clock Pulse Generator + * + * Copyright (C) 2021 Renesas Electronics Corp. + * + * Based on rcar-gen3-cpg.c + * + * Copyright (C) 2015-2018 Glider bvba + * Copyright (C) 2019 Renesas Electronics Corp. + */ + +#include <linux/bitfield.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-gen4-cpg.h" +#include "rcar-cpg-lib.h" + +static const struct rcar_gen4_cpg_pll_config *cpg_pll_config __initdata; +static unsigned int cpg_clk_extalr __initdata; +static u32 cpg_mode __initdata; + +/* + * Z0 Clock & Z1 Clock + */ +#define CPG_FRQCRB 0x00000804 +#define CPG_FRQCRB_KICK BIT(31) +#define CPG_FRQCRC 0x00000808 + +struct cpg_z_clk { + struct clk_hw hw; + void __iomem *reg; + void __iomem *kick_reg; + unsigned long max_rate; /* Maximum rate for normal mode */ + unsigned int fixed_div; + u32 mask; +}; + +#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; + u32 val; + + val = readl(zclk->reg) & zclk->mask; + mult = 32 - (val >> __ffs(zclk->mask)); + + return DIV_ROUND_CLOSEST_ULL((u64)parent_rate * mult, + 32 * zclk->fixed_div); +} + +static int cpg_z_clk_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct cpg_z_clk *zclk = to_z_clk(hw); + unsigned int min_mult, max_mult, mult; + unsigned long rate, prate; + + rate = min(req->rate, req->max_rate); + if (rate <= zclk->max_rate) { + /* Set parent rate to initial value for normal modes */ + prate = zclk->max_rate; + } else { + /* Set increased parent rate for boost modes */ + prate = rate; + } + req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), + prate * zclk->fixed_div); + + prate = req->best_parent_rate / zclk->fixed_div; + min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL); + max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL); + if (max_mult < min_mult) + return -EINVAL; + + mult = DIV_ROUND_CLOSEST_ULL(rate * 32ULL, prate); + mult = clamp(mult, min_mult, max_mult); + + req->rate = DIV_ROUND_CLOSEST_ULL((u64)prate * mult, 32); + return 0; +} + +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; + unsigned int i; + + mult = DIV64_U64_ROUND_CLOSEST(rate * 32ULL * zclk->fixed_div, + parent_rate); + mult = clamp(mult, 1U, 32U); + + if (readl(zclk->kick_reg) & CPG_FRQCRB_KICK) + return -EBUSY; + + cpg_reg_modify(zclk->reg, zclk->mask, (32 - mult) << __ffs(zclk->mask)); + + /* + * Set KICK bit in FRQCRB to update hardware setting and wait for + * clock change completion. + */ + cpg_reg_modify(zclk->kick_reg, 0, CPG_FRQCRB_KICK); + + /* + * 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, + .determine_rate = cpg_z_clk_determine_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 *reg, + unsigned int div, + unsigned int offset) +{ + 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 = CLK_SET_RATE_PARENT; + init.parent_names = &parent_name; + init.num_parents = 1; + + zclk->reg = reg + CPG_FRQCRC; + zclk->kick_reg = reg + CPG_FRQCRB; + zclk->hw.init = &init; + zclk->mask = GENMASK(offset + 4, offset); + zclk->fixed_div = div; /* PLLVCO x 1/div x SYS-CPU divider */ + + clk = clk_register(NULL, &zclk->hw); + if (IS_ERR(clk)) { + kfree(zclk); + return clk; + } + + zclk->max_rate = clk_hw_get_rate(clk_hw_get_parent(&zclk->hw)) / + zclk->fixed_div; + return clk; +} + +/* + * RPC Clocks + */ +static const struct clk_div_table cpg_rpcsrc_div_table[] = { + { 0, 4 }, { 1, 6 }, { 2, 5 }, { 3, 6 }, { 0, 0 }, +}; + +struct clk * __init rcar_gen4_cpg_clk_register(struct device *dev, + const struct cpg_core_clk *core, const struct cpg_mssr_info *info, + struct clk **clks, void __iomem *base, + struct raw_notifier_head *notifiers) +{ + const struct clk *parent; + unsigned int mult = 1; + unsigned int div = 1; + u32 value; + + parent = clks[core->parent & 0xffff]; /* some types use high bits */ + if (IS_ERR(parent)) + return ERR_CAST(parent); + + switch (core->type) { + case CLK_TYPE_GEN4_MAIN: + div = cpg_pll_config->extal_div; + break; + + case CLK_TYPE_GEN4_PLL1: + mult = cpg_pll_config->pll1_mult; + div = cpg_pll_config->pll1_div; + break; + + case CLK_TYPE_GEN4_PLL2: + mult = cpg_pll_config->pll2_mult; + div = cpg_pll_config->pll2_div; + break; + + case CLK_TYPE_GEN4_PLL3: + mult = cpg_pll_config->pll3_mult; + div = cpg_pll_config->pll3_div; + break; + + case CLK_TYPE_GEN4_PLL4: + mult = cpg_pll_config->pll4_mult; + div = cpg_pll_config->pll4_div; + break; + + case CLK_TYPE_GEN4_PLL5: + mult = cpg_pll_config->pll5_mult; + div = cpg_pll_config->pll5_div; + break; + + case CLK_TYPE_GEN4_PLL6: + mult = cpg_pll_config->pll6_mult; + div = cpg_pll_config->pll6_div; + break; + + case CLK_TYPE_GEN4_PLL2X_3X: + value = readl(base + core->offset); + mult = (((value >> 24) & 0x7f) + 1) * 2; + break; + + case CLK_TYPE_GEN4_Z: + return cpg_z_clk_register(core->name, __clk_get_name(parent), + base, core->div, core->offset); + + case CLK_TYPE_GEN4_SDSRC: + div = ((readl(base + SD0CKCR1) >> 29) & 0x03) + 4; + break; + + case CLK_TYPE_GEN4_SDH: + return cpg_sdh_clk_register(core->name, base + core->offset, + __clk_get_name(parent), notifiers); + + case CLK_TYPE_GEN4_SD: + return cpg_sd_clk_register(core->name, base + core->offset, + __clk_get_name(parent)); + + case CLK_TYPE_GEN4_MDSEL: + /* + * Clock selectable between two parents and two fixed dividers + * using a mode pin + */ + if (cpg_mode & BIT(core->offset)) { + div = core->div & 0xffff; + } else { + parent = clks[core->parent >> 16]; + if (IS_ERR(parent)) + return ERR_CAST(parent); + div = core->div >> 16; + } + mult = 1; + break; + + case CLK_TYPE_GEN4_OSC: + /* + * Clock combining OSC EXTAL predivider and a fixed divider + */ + div = cpg_pll_config->osc_prediv * core->div; + break; + + case CLK_TYPE_GEN4_RPCSRC: + return clk_register_divider_table(NULL, core->name, + __clk_get_name(parent), 0, + base + CPG_RPCCKCR, 3, 2, 0, + cpg_rpcsrc_div_table, + &cpg_lock); + + case CLK_TYPE_GEN4_RPC: + return cpg_rpc_clk_register(core->name, base + CPG_RPCCKCR, + __clk_get_name(parent), notifiers); + + case CLK_TYPE_GEN4_RPCD2: + return cpg_rpcd2_clk_register(core->name, base + CPG_RPCCKCR, + __clk_get_name(parent)); + + default: + return ERR_PTR(-EINVAL); + } + + return clk_register_fixed_factor(NULL, core->name, + __clk_get_name(parent), 0, mult, div); +} + +int __init rcar_gen4_cpg_init(const struct rcar_gen4_cpg_pll_config *config, + unsigned int clk_extalr, u32 mode) +{ + cpg_pll_config = config; + cpg_clk_extalr = clk_extalr; + cpg_mode = mode; + + spin_lock_init(&cpg_lock); + + return 0; +} |