diff options
Diffstat (limited to 'drivers/clk/pistachio/clk-pll.c')
| -rw-r--r-- | drivers/clk/pistachio/clk-pll.c | 513 |
1 files changed, 513 insertions, 0 deletions
diff --git a/drivers/clk/pistachio/clk-pll.c b/drivers/clk/pistachio/clk-pll.c new file mode 100644 index 000000000..7e8daab90 --- /dev/null +++ b/drivers/clk/pistachio/clk-pll.c @@ -0,0 +1,513 @@ +/* + * Copyright (C) 2014 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) "%s: " fmt, __func__ + +#include <linux/clk-provider.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/slab.h> + +#include "clk.h" + +#define PLL_STATUS 0x0 +#define PLL_STATUS_LOCK BIT(0) + +#define PLL_CTRL1 0x4 +#define PLL_CTRL1_REFDIV_SHIFT 0 +#define PLL_CTRL1_REFDIV_MASK 0x3f +#define PLL_CTRL1_FBDIV_SHIFT 6 +#define PLL_CTRL1_FBDIV_MASK 0xfff +#define PLL_INT_CTRL1_POSTDIV1_SHIFT 18 +#define PLL_INT_CTRL1_POSTDIV1_MASK 0x7 +#define PLL_INT_CTRL1_POSTDIV2_SHIFT 21 +#define PLL_INT_CTRL1_POSTDIV2_MASK 0x7 +#define PLL_INT_CTRL1_PD BIT(24) +#define PLL_INT_CTRL1_DSMPD BIT(25) +#define PLL_INT_CTRL1_FOUTPOSTDIVPD BIT(26) +#define PLL_INT_CTRL1_FOUTVCOPD BIT(27) + +#define PLL_CTRL2 0x8 +#define PLL_FRAC_CTRL2_FRAC_SHIFT 0 +#define PLL_FRAC_CTRL2_FRAC_MASK 0xffffff +#define PLL_FRAC_CTRL2_POSTDIV1_SHIFT 24 +#define PLL_FRAC_CTRL2_POSTDIV1_MASK 0x7 +#define PLL_FRAC_CTRL2_POSTDIV2_SHIFT 27 +#define PLL_FRAC_CTRL2_POSTDIV2_MASK 0x7 +#define PLL_INT_CTRL2_BYPASS BIT(28) + +#define PLL_CTRL3 0xc +#define PLL_FRAC_CTRL3_PD BIT(0) +#define PLL_FRAC_CTRL3_DACPD BIT(1) +#define PLL_FRAC_CTRL3_DSMPD BIT(2) +#define PLL_FRAC_CTRL3_FOUTPOSTDIVPD BIT(3) +#define PLL_FRAC_CTRL3_FOUT4PHASEPD BIT(4) +#define PLL_FRAC_CTRL3_FOUTVCOPD BIT(5) + +#define PLL_CTRL4 0x10 +#define PLL_FRAC_CTRL4_BYPASS BIT(28) + +#define MIN_PFD 9600000UL +#define MIN_VCO_LA 400000000UL +#define MAX_VCO_LA 1600000000UL +#define MIN_VCO_FRAC_INT 600000000UL +#define MAX_VCO_FRAC_INT 1600000000UL +#define MIN_VCO_FRAC_FRAC 600000000UL +#define MAX_VCO_FRAC_FRAC 2400000000UL +#define MIN_OUTPUT_LA 8000000UL +#define MAX_OUTPUT_LA 1600000000UL +#define MIN_OUTPUT_FRAC 12000000UL +#define MAX_OUTPUT_FRAC 1600000000UL + +/* Fractional PLL operating modes */ +enum pll_mode { + PLL_MODE_FRAC, + PLL_MODE_INT, +}; + +struct pistachio_clk_pll { + struct clk_hw hw; + void __iomem *base; + struct pistachio_pll_rate_table *rates; + unsigned int nr_rates; +}; + +static inline u32 pll_readl(struct pistachio_clk_pll *pll, u32 reg) +{ + return readl(pll->base + reg); +} + +static inline void pll_writel(struct pistachio_clk_pll *pll, u32 val, u32 reg) +{ + writel(val, pll->base + reg); +} + +static inline void pll_lock(struct pistachio_clk_pll *pll) +{ + while (!(pll_readl(pll, PLL_STATUS) & PLL_STATUS_LOCK)) + cpu_relax(); +} + +static inline u64 do_div_round_closest(u64 dividend, u64 divisor) +{ + dividend += divisor / 2; + return div64_u64(dividend, divisor); +} + +static inline struct pistachio_clk_pll *to_pistachio_pll(struct clk_hw *hw) +{ + return container_of(hw, struct pistachio_clk_pll, hw); +} + +static inline enum pll_mode pll_frac_get_mode(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val; + + val = pll_readl(pll, PLL_CTRL3) & PLL_FRAC_CTRL3_DSMPD; + return val ? PLL_MODE_INT : PLL_MODE_FRAC; +} + +static inline void pll_frac_set_mode(struct clk_hw *hw, enum pll_mode mode) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val; + + val = pll_readl(pll, PLL_CTRL3); + if (mode == PLL_MODE_INT) + val |= PLL_FRAC_CTRL3_DSMPD | PLL_FRAC_CTRL3_DACPD; + else + val &= ~(PLL_FRAC_CTRL3_DSMPD | PLL_FRAC_CTRL3_DACPD); + + pll_writel(pll, val, PLL_CTRL3); +} + +static struct pistachio_pll_rate_table * +pll_get_params(struct pistachio_clk_pll *pll, unsigned long fref, + unsigned long fout) +{ + unsigned int i; + + for (i = 0; i < pll->nr_rates; i++) { + if (pll->rates[i].fref == fref && pll->rates[i].fout == fout) + return &pll->rates[i]; + } + + return NULL; +} + +static long pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + unsigned int i; + + for (i = 0; i < pll->nr_rates; i++) { + if (i > 0 && pll->rates[i].fref == *parent_rate && + pll->rates[i].fout <= rate) + return pll->rates[i - 1].fout; + } + + return pll->rates[0].fout; +} + +static int pll_gf40lp_frac_enable(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val; + + val = pll_readl(pll, PLL_CTRL3); + val &= ~(PLL_FRAC_CTRL3_PD | PLL_FRAC_CTRL3_FOUTPOSTDIVPD | + PLL_FRAC_CTRL3_FOUT4PHASEPD | PLL_FRAC_CTRL3_FOUTVCOPD); + pll_writel(pll, val, PLL_CTRL3); + + val = pll_readl(pll, PLL_CTRL4); + val &= ~PLL_FRAC_CTRL4_BYPASS; + pll_writel(pll, val, PLL_CTRL4); + + pll_lock(pll); + + return 0; +} + +static void pll_gf40lp_frac_disable(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val; + + val = pll_readl(pll, PLL_CTRL3); + val |= PLL_FRAC_CTRL3_PD; + pll_writel(pll, val, PLL_CTRL3); +} + +static int pll_gf40lp_frac_is_enabled(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + + return !(pll_readl(pll, PLL_CTRL3) & PLL_FRAC_CTRL3_PD); +} + +static int pll_gf40lp_frac_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + struct pistachio_pll_rate_table *params; + int enabled = pll_gf40lp_frac_is_enabled(hw); + u64 val, vco, old_postdiv1, old_postdiv2; + const char *name = clk_hw_get_name(hw); + + if (rate < MIN_OUTPUT_FRAC || rate > MAX_OUTPUT_FRAC) + return -EINVAL; + + params = pll_get_params(pll, parent_rate, rate); + if (!params || !params->refdiv) + return -EINVAL; + + /* calculate vco */ + vco = params->fref; + vco *= (params->fbdiv << 24) + params->frac; + vco = div64_u64(vco, params->refdiv << 24); + + if (vco < MIN_VCO_FRAC_FRAC || vco > MAX_VCO_FRAC_FRAC) + pr_warn("%s: VCO %llu is out of range %lu..%lu\n", name, vco, + MIN_VCO_FRAC_FRAC, MAX_VCO_FRAC_FRAC); + + val = div64_u64(params->fref, params->refdiv); + if (val < MIN_PFD) + pr_warn("%s: PFD %llu is too low (min %lu)\n", + name, val, MIN_PFD); + if (val > vco / 16) + pr_warn("%s: PFD %llu is too high (max %llu)\n", + name, val, vco / 16); + + val = pll_readl(pll, PLL_CTRL1); + val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) | + (PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT)); + val |= (params->refdiv << PLL_CTRL1_REFDIV_SHIFT) | + (params->fbdiv << PLL_CTRL1_FBDIV_SHIFT); + pll_writel(pll, val, PLL_CTRL1); + + val = pll_readl(pll, PLL_CTRL2); + + old_postdiv1 = (val >> PLL_FRAC_CTRL2_POSTDIV1_SHIFT) & + PLL_FRAC_CTRL2_POSTDIV1_MASK; + old_postdiv2 = (val >> PLL_FRAC_CTRL2_POSTDIV2_SHIFT) & + PLL_FRAC_CTRL2_POSTDIV2_MASK; + if (enabled && + (params->postdiv1 != old_postdiv1 || + params->postdiv2 != old_postdiv2)) + pr_warn("%s: changing postdiv while PLL is enabled\n", name); + + if (params->postdiv2 > params->postdiv1) + pr_warn("%s: postdiv2 should not exceed postdiv1\n", name); + + val &= ~((PLL_FRAC_CTRL2_FRAC_MASK << PLL_FRAC_CTRL2_FRAC_SHIFT) | + (PLL_FRAC_CTRL2_POSTDIV1_MASK << + PLL_FRAC_CTRL2_POSTDIV1_SHIFT) | + (PLL_FRAC_CTRL2_POSTDIV2_MASK << + PLL_FRAC_CTRL2_POSTDIV2_SHIFT)); + val |= (params->frac << PLL_FRAC_CTRL2_FRAC_SHIFT) | + (params->postdiv1 << PLL_FRAC_CTRL2_POSTDIV1_SHIFT) | + (params->postdiv2 << PLL_FRAC_CTRL2_POSTDIV2_SHIFT); + pll_writel(pll, val, PLL_CTRL2); + + /* set operating mode */ + if (params->frac) + pll_frac_set_mode(hw, PLL_MODE_FRAC); + else + pll_frac_set_mode(hw, PLL_MODE_INT); + + if (enabled) + pll_lock(pll); + + return 0; +} + +static unsigned long pll_gf40lp_frac_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u64 val, prediv, fbdiv, frac, postdiv1, postdiv2, rate; + + val = pll_readl(pll, PLL_CTRL1); + prediv = (val >> PLL_CTRL1_REFDIV_SHIFT) & PLL_CTRL1_REFDIV_MASK; + fbdiv = (val >> PLL_CTRL1_FBDIV_SHIFT) & PLL_CTRL1_FBDIV_MASK; + + val = pll_readl(pll, PLL_CTRL2); + postdiv1 = (val >> PLL_FRAC_CTRL2_POSTDIV1_SHIFT) & + PLL_FRAC_CTRL2_POSTDIV1_MASK; + postdiv2 = (val >> PLL_FRAC_CTRL2_POSTDIV2_SHIFT) & + PLL_FRAC_CTRL2_POSTDIV2_MASK; + frac = (val >> PLL_FRAC_CTRL2_FRAC_SHIFT) & PLL_FRAC_CTRL2_FRAC_MASK; + + /* get operating mode (int/frac) and calculate rate accordingly */ + rate = parent_rate; + if (pll_frac_get_mode(hw) == PLL_MODE_FRAC) + rate *= (fbdiv << 24) + frac; + else + rate *= (fbdiv << 24); + + rate = do_div_round_closest(rate, (prediv * postdiv1 * postdiv2) << 24); + + return rate; +} + +static struct clk_ops pll_gf40lp_frac_ops = { + .enable = pll_gf40lp_frac_enable, + .disable = pll_gf40lp_frac_disable, + .is_enabled = pll_gf40lp_frac_is_enabled, + .recalc_rate = pll_gf40lp_frac_recalc_rate, + .round_rate = pll_round_rate, + .set_rate = pll_gf40lp_frac_set_rate, +}; + +static struct clk_ops pll_gf40lp_frac_fixed_ops = { + .enable = pll_gf40lp_frac_enable, + .disable = pll_gf40lp_frac_disable, + .is_enabled = pll_gf40lp_frac_is_enabled, + .recalc_rate = pll_gf40lp_frac_recalc_rate, +}; + +static int pll_gf40lp_laint_enable(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val; + + val = pll_readl(pll, PLL_CTRL1); + val &= ~(PLL_INT_CTRL1_PD | + PLL_INT_CTRL1_FOUTPOSTDIVPD | PLL_INT_CTRL1_FOUTVCOPD); + pll_writel(pll, val, PLL_CTRL1); + + val = pll_readl(pll, PLL_CTRL2); + val &= ~PLL_INT_CTRL2_BYPASS; + pll_writel(pll, val, PLL_CTRL2); + + pll_lock(pll); + + return 0; +} + +static void pll_gf40lp_laint_disable(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val; + + val = pll_readl(pll, PLL_CTRL1); + val |= PLL_INT_CTRL1_PD; + pll_writel(pll, val, PLL_CTRL1); +} + +static int pll_gf40lp_laint_is_enabled(struct clk_hw *hw) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + + return !(pll_readl(pll, PLL_CTRL1) & PLL_INT_CTRL1_PD); +} + +static int pll_gf40lp_laint_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + struct pistachio_pll_rate_table *params; + int enabled = pll_gf40lp_laint_is_enabled(hw); + u32 val, vco, old_postdiv1, old_postdiv2; + const char *name = clk_hw_get_name(hw); + + if (rate < MIN_OUTPUT_LA || rate > MAX_OUTPUT_LA) + return -EINVAL; + + params = pll_get_params(pll, parent_rate, rate); + if (!params || !params->refdiv) + return -EINVAL; + + vco = div_u64(params->fref * params->fbdiv, params->refdiv); + if (vco < MIN_VCO_LA || vco > MAX_VCO_LA) + pr_warn("%s: VCO %u is out of range %lu..%lu\n", name, vco, + MIN_VCO_LA, MAX_VCO_LA); + + val = div_u64(params->fref, params->refdiv); + if (val < MIN_PFD) + pr_warn("%s: PFD %u is too low (min %lu)\n", + name, val, MIN_PFD); + if (val > vco / 16) + pr_warn("%s: PFD %u is too high (max %u)\n", + name, val, vco / 16); + + val = pll_readl(pll, PLL_CTRL1); + + old_postdiv1 = (val >> PLL_INT_CTRL1_POSTDIV1_SHIFT) & + PLL_INT_CTRL1_POSTDIV1_MASK; + old_postdiv2 = (val >> PLL_INT_CTRL1_POSTDIV2_SHIFT) & + PLL_INT_CTRL1_POSTDIV2_MASK; + if (enabled && + (params->postdiv1 != old_postdiv1 || + params->postdiv2 != old_postdiv2)) + pr_warn("%s: changing postdiv while PLL is enabled\n", name); + + if (params->postdiv2 > params->postdiv1) + pr_warn("%s: postdiv2 should not exceed postdiv1\n", name); + + val &= ~((PLL_CTRL1_REFDIV_MASK << PLL_CTRL1_REFDIV_SHIFT) | + (PLL_CTRL1_FBDIV_MASK << PLL_CTRL1_FBDIV_SHIFT) | + (PLL_INT_CTRL1_POSTDIV1_MASK << PLL_INT_CTRL1_POSTDIV1_SHIFT) | + (PLL_INT_CTRL1_POSTDIV2_MASK << PLL_INT_CTRL1_POSTDIV2_SHIFT)); + val |= (params->refdiv << PLL_CTRL1_REFDIV_SHIFT) | + (params->fbdiv << PLL_CTRL1_FBDIV_SHIFT) | + (params->postdiv1 << PLL_INT_CTRL1_POSTDIV1_SHIFT) | + (params->postdiv2 << PLL_INT_CTRL1_POSTDIV2_SHIFT); + pll_writel(pll, val, PLL_CTRL1); + + if (enabled) + pll_lock(pll); + + return 0; +} + +static unsigned long pll_gf40lp_laint_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct pistachio_clk_pll *pll = to_pistachio_pll(hw); + u32 val, prediv, fbdiv, postdiv1, postdiv2; + u64 rate = parent_rate; + + val = pll_readl(pll, PLL_CTRL1); + prediv = (val >> PLL_CTRL1_REFDIV_SHIFT) & PLL_CTRL1_REFDIV_MASK; + fbdiv = (val >> PLL_CTRL1_FBDIV_SHIFT) & PLL_CTRL1_FBDIV_MASK; + postdiv1 = (val >> PLL_INT_CTRL1_POSTDIV1_SHIFT) & + PLL_INT_CTRL1_POSTDIV1_MASK; + postdiv2 = (val >> PLL_INT_CTRL1_POSTDIV2_SHIFT) & + PLL_INT_CTRL1_POSTDIV2_MASK; + + rate *= fbdiv; + rate = do_div_round_closest(rate, prediv * postdiv1 * postdiv2); + + return rate; +} + +static struct clk_ops pll_gf40lp_laint_ops = { + .enable = pll_gf40lp_laint_enable, + .disable = pll_gf40lp_laint_disable, + .is_enabled = pll_gf40lp_laint_is_enabled, + .recalc_rate = pll_gf40lp_laint_recalc_rate, + .round_rate = pll_round_rate, + .set_rate = pll_gf40lp_laint_set_rate, +}; + +static struct clk_ops pll_gf40lp_laint_fixed_ops = { + .enable = pll_gf40lp_laint_enable, + .disable = pll_gf40lp_laint_disable, + .is_enabled = pll_gf40lp_laint_is_enabled, + .recalc_rate = pll_gf40lp_laint_recalc_rate, +}; + +static struct clk *pll_register(const char *name, const char *parent_name, + unsigned long flags, void __iomem *base, + enum pistachio_pll_type type, + struct pistachio_pll_rate_table *rates, + unsigned int nr_rates) +{ + struct pistachio_clk_pll *pll; + struct clk_init_data init; + struct clk *clk; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.flags = flags | CLK_GET_RATE_NOCACHE; + init.parent_names = &parent_name; + init.num_parents = 1; + + switch (type) { + case PLL_GF40LP_FRAC: + if (rates) + init.ops = &pll_gf40lp_frac_ops; + else + init.ops = &pll_gf40lp_frac_fixed_ops; + break; + case PLL_GF40LP_LAINT: + if (rates) + init.ops = &pll_gf40lp_laint_ops; + else + init.ops = &pll_gf40lp_laint_fixed_ops; + break; + default: + pr_err("Unrecognized PLL type %u\n", type); + kfree(pll); + return ERR_PTR(-EINVAL); + } + + pll->hw.init = &init; + pll->base = base; + pll->rates = rates; + pll->nr_rates = nr_rates; + + clk = clk_register(NULL, &pll->hw); + if (IS_ERR(clk)) + kfree(pll); + + return clk; +} + +void pistachio_clk_register_pll(struct pistachio_clk_provider *p, + struct pistachio_pll *pll, + unsigned int num) +{ + struct clk *clk; + unsigned int i; + + for (i = 0; i < num; i++) { + clk = pll_register(pll[i].name, pll[i].parent, + 0, p->base + pll[i].reg_base, + pll[i].type, pll[i].rates, + pll[i].nr_rates); + p->clk_data.clks[pll[i].id] = clk; + } +} |