From cc3e8f97bbd370b51b3bb7fec391d65d461d7d02 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 2 Jul 2021 11:58:05 +0200 Subject: [PATCH] clk: renesas: r8a779a0: Add Z0 and Z1 clock support Add support for the Z0 and Z1 (Cortex-A76 Sub-system 0 and 1) clocks, based on the existing support for Z clocks on R-Car Gen3. As the offsets of the CPG_FRQCRB and CPG_FRQCRC registers on R-Car V3U differ from the offsets on other R-Car Gen3 SoCs, we cannot use the existing R-Car Gen3 support as-is. For now, just make a copy, and change the register offsets. Signed-off-by: Geert Uytterhoeven Reviewed-by: Yoshihiro Shimoda Link: https://lore.kernel.org/r/2112e3bc870580c623bdecfeff8c74739699c610.1625219713.git.geert+renesas@glider.be --- drivers/clk/renesas/r8a779a0-cpg-mssr.c | 158 ++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) diff --git a/drivers/clk/renesas/r8a779a0-cpg-mssr.c b/drivers/clk/renesas/r8a779a0-cpg-mssr.c index 286687e..1ced31b 100644 --- a/drivers/clk/renesas/r8a779a0-cpg-mssr.c +++ b/drivers/clk/renesas/r8a779a0-cpg-mssr.c @@ -33,6 +33,7 @@ enum rcar_r8a779a0_clk_types { CLK_TYPE_R8A779A0_PLL1, CLK_TYPE_R8A779A0_PLL2X_3X, /* PLL[23][01] */ CLK_TYPE_R8A779A0_PLL5, + CLK_TYPE_R8A779A0_Z, CLK_TYPE_R8A779A0_SD, CLK_TYPE_R8A779A0_MDSEL, /* Select parent/divider using mode pin */ CLK_TYPE_R8A779A0_OSC, /* OSC EXTAL predivider and fixed divider */ @@ -84,6 +85,10 @@ enum clk_ids { DEF_BASE(_name, _id, CLK_TYPE_R8A779A0_PLL2X_3X, CLK_MAIN, \ .offset = _offset) +#define DEF_Z(_name, _id, _parent, _div, _offset) \ + DEF_BASE(_name, _id, CLK_TYPE_R8A779A0_Z, _parent, .div = _div, \ + .offset = _offset) + #define DEF_SD(_name, _id, _parent, _offset) \ DEF_BASE(_name, _id, CLK_TYPE_R8A779A0_SD, _parent, .offset = _offset) @@ -122,6 +127,8 @@ static const struct cpg_core_clk r8a779a0_core_clks[] __initconst = { DEF_RATE(".oco", CLK_OCO, 32768), /* Core Clock Outputs */ + DEF_Z("z0", R8A779A0_CLK_Z0, CLK_PLL20, 2, 0), + DEF_Z("z1", R8A779A0_CLK_Z1, CLK_PLL21, 2, 8), DEF_FIXED("zx", R8A779A0_CLK_ZX, CLK_PLL20_DIV2, 2, 1), DEF_FIXED("s1d1", R8A779A0_CLK_S1D1, CLK_S1, 1, 1), DEF_FIXED("s1d2", R8A779A0_CLK_S1D2, CLK_S1, 2, 1), @@ -260,6 +267,153 @@ static const struct rcar_r8a779a0_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; +} + static struct clk * __init rcar_r8a779a0_cpg_clk_register(struct device *dev, const struct cpg_core_clk *core, const struct cpg_mssr_info *info, struct clk **clks, void __iomem *base, @@ -294,6 +448,10 @@ static struct clk * __init rcar_r8a779a0_cpg_clk_register(struct device *dev, div = cpg_pll_config->pll5_div; break; + case CLK_TYPE_R8A779A0_Z: + return cpg_z_clk_register(core->name, __clk_get_name(parent), + base, core->div, core->offset); + case CLK_TYPE_R8A779A0_SD: return cpg_sd_clk_register(core->name, base, core->offset, __clk_get_name(parent), notifiers, -- 2.7.4