diff options
Diffstat (limited to 'drivers/clk/rockchip/clk-pll.c')
| -rw-r--r-- | drivers/clk/rockchip/clk-pll.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk-pll.c b/drivers/clk/rockchip/clk-pll.c new file mode 100644 index 000000000000..f2a1c7abf4d9 --- /dev/null +++ b/drivers/clk/rockchip/clk-pll.c @@ -0,0 +1,431 @@ +/* + * Copyright (c) 2014 MundoReader S.L. + * Author: Heiko Stuebner <heiko@sntech.de> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <asm/div64.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/regmap.h> +#include "clk.h" + +#define PLL_MODE_MASK 0x3 +#define PLL_MODE_SLOW 0x0 +#define PLL_MODE_NORM 0x1 +#define PLL_MODE_DEEP 0x2 + +struct rockchip_clk_pll { + struct clk_hw hw; + + struct clk_mux pll_mux; + const struct clk_ops *pll_mux_ops; + + struct notifier_block clk_nb; + bool rate_change_remuxed; + + void __iomem *reg_base; + int lock_offset; + unsigned int lock_shift; + enum rockchip_pll_type type; + const struct rockchip_pll_rate_table *rate_table; + unsigned int rate_count; + spinlock_t *lock; +}; + +#define to_rockchip_clk_pll(_hw) container_of(_hw, struct rockchip_clk_pll, hw) +#define to_rockchip_clk_pll_nb(nb) \ + container_of(nb, struct rockchip_clk_pll, clk_nb) + +static const struct rockchip_pll_rate_table *rockchip_get_pll_settings( + struct rockchip_clk_pll *pll, unsigned long rate) +{ + const struct rockchip_pll_rate_table *rate_table = pll->rate_table; + int i; + + for (i = 0; i < pll->rate_count; i++) { + if (rate == rate_table[i].rate) + return &rate_table[i]; + } + + return NULL; +} + +static long rockchip_pll_round_rate(struct clk_hw *hw, + unsigned long drate, unsigned long *prate) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + const struct rockchip_pll_rate_table *rate_table = pll->rate_table; + int i; + + /* Assumming rate_table is in descending order */ + for (i = 0; i < pll->rate_count; i++) { + if (drate >= rate_table[i].rate) + return rate_table[i].rate; + } + + /* return minimum supported value */ + return rate_table[i - 1].rate; +} + +/* + * Wait for the pll to reach the locked state. + * The calling set_rate function is responsible for making sure the + * grf regmap is available. + */ +static int rockchip_pll_wait_lock(struct rockchip_clk_pll *pll) +{ + struct regmap *grf = rockchip_clk_get_grf(); + unsigned int val; + int delay = 24000000, ret; + + while (delay > 0) { + ret = regmap_read(grf, pll->lock_offset, &val); + if (ret) { + pr_err("%s: failed to read pll lock status: %d\n", + __func__, ret); + return ret; + } + + if (val & BIT(pll->lock_shift)) + return 0; + delay--; + } + + pr_err("%s: timeout waiting for pll to lock\n", __func__); + return -ETIMEDOUT; +} + +/** + * Set pll mux when changing the pll rate. + * This makes sure to move the pll mux away from the actual pll before + * changing its rate and back to the original parent after the change. + */ +static int rockchip_pll_notifier_cb(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll_nb(nb); + struct clk_mux *pll_mux = &pll->pll_mux; + const struct clk_ops *pll_mux_ops = pll->pll_mux_ops; + int cur_parent; + + switch (event) { + case PRE_RATE_CHANGE: + cur_parent = pll_mux_ops->get_parent(&pll_mux->hw); + if (cur_parent == PLL_MODE_NORM) { + pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_SLOW); + pll->rate_change_remuxed = 1; + } + break; + case POST_RATE_CHANGE: + if (pll->rate_change_remuxed) { + pll_mux_ops->set_parent(&pll_mux->hw, PLL_MODE_NORM); + pll->rate_change_remuxed = 0; + } + break; + } + + return NOTIFY_OK; +} + +/** + * PLL used in RK3066, RK3188 and RK3288 + */ + +#define RK3066_PLL_RESET_DELAY(nr) ((nr * 500) / 24 + 1) + +#define RK3066_PLLCON(i) (i * 0x4) +#define RK3066_PLLCON0_OD_MASK 0xf +#define RK3066_PLLCON0_OD_SHIFT 0 +#define RK3066_PLLCON0_NR_MASK 0x3f +#define RK3066_PLLCON0_NR_SHIFT 8 +#define RK3066_PLLCON1_NF_MASK 0x1fff +#define RK3066_PLLCON1_NF_SHIFT 0 +#define RK3066_PLLCON2_BWADJ_MASK 0xfff +#define RK3066_PLLCON2_BWADJ_SHIFT 0 +#define RK3066_PLLCON3_RESET (1 << 5) +#define RK3066_PLLCON3_PWRDOWN (1 << 1) +#define RK3066_PLLCON3_BYPASS (1 << 0) + +static unsigned long rockchip_rk3066_pll_recalc_rate(struct clk_hw *hw, + unsigned long prate) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + u64 nf, nr, no, rate64 = prate; + u32 pllcon; + + pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(3)); + if (pllcon & RK3066_PLLCON3_BYPASS) { + pr_debug("%s: pll %s is bypassed\n", __func__, + __clk_get_name(hw->clk)); + return prate; + } + + pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(1)); + nf = (pllcon >> RK3066_PLLCON1_NF_SHIFT) & RK3066_PLLCON1_NF_MASK; + + pllcon = readl_relaxed(pll->reg_base + RK3066_PLLCON(0)); + nr = (pllcon >> RK3066_PLLCON0_NR_SHIFT) & RK3066_PLLCON0_NR_MASK; + no = (pllcon >> RK3066_PLLCON0_OD_SHIFT) & RK3066_PLLCON0_OD_MASK; + + rate64 *= (nf + 1); + do_div(rate64, nr + 1); + do_div(rate64, no + 1); + + return (unsigned long)rate64; +} + +static int rockchip_rk3066_pll_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + const struct rockchip_pll_rate_table *rate; + unsigned long old_rate = rockchip_rk3066_pll_recalc_rate(hw, prate); + struct regmap *grf = rockchip_clk_get_grf(); + int ret; + + if (IS_ERR(grf)) { + pr_debug("%s: grf regmap not available, aborting rate change\n", + __func__); + return PTR_ERR(grf); + } + + pr_debug("%s: changing %s from %lu to %lu with a parent rate of %lu\n", + __func__, __clk_get_name(hw->clk), old_rate, drate, prate); + + /* Get required rate settings from table */ + rate = rockchip_get_pll_settings(pll, drate); + if (!rate) { + pr_err("%s: Invalid rate : %lu for pll clk %s\n", __func__, + drate, __clk_get_name(hw->clk)); + return -EINVAL; + } + + pr_debug("%s: rate settings for %lu (nr, no, nf): (%d, %d, %d)\n", + __func__, rate->rate, rate->nr, rate->no, rate->nf); + + /* enter reset mode */ + writel(HIWORD_UPDATE(RK3066_PLLCON3_RESET, RK3066_PLLCON3_RESET, 0), + pll->reg_base + RK3066_PLLCON(3)); + + /* update pll values */ + writel(HIWORD_UPDATE(rate->nr - 1, RK3066_PLLCON0_NR_MASK, + RK3066_PLLCON0_NR_SHIFT) | + HIWORD_UPDATE(rate->no - 1, RK3066_PLLCON0_OD_MASK, + RK3066_PLLCON0_OD_SHIFT), + pll->reg_base + RK3066_PLLCON(0)); + + writel_relaxed(HIWORD_UPDATE(rate->nf - 1, RK3066_PLLCON1_NF_MASK, + RK3066_PLLCON1_NF_SHIFT), + pll->reg_base + RK3066_PLLCON(1)); + writel_relaxed(HIWORD_UPDATE(rate->bwadj, RK3066_PLLCON2_BWADJ_MASK, + RK3066_PLLCON2_BWADJ_SHIFT), + pll->reg_base + RK3066_PLLCON(2)); + + /* leave reset and wait the reset_delay */ + writel(HIWORD_UPDATE(0, RK3066_PLLCON3_RESET, 0), + pll->reg_base + RK3066_PLLCON(3)); + udelay(RK3066_PLL_RESET_DELAY(rate->nr)); + + /* wait for the pll to lock */ + ret = rockchip_pll_wait_lock(pll); + if (ret) { + pr_warn("%s: pll did not lock, trying to restore old rate %lu\n", + __func__, old_rate); + rockchip_rk3066_pll_set_rate(hw, old_rate, prate); + } + + return ret; +} + +static int rockchip_rk3066_pll_enable(struct clk_hw *hw) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + + writel(HIWORD_UPDATE(0, RK3066_PLLCON3_PWRDOWN, 0), + pll->reg_base + RK3066_PLLCON(3)); + + return 0; +} + +static void rockchip_rk3066_pll_disable(struct clk_hw *hw) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + + writel(HIWORD_UPDATE(RK3066_PLLCON3_PWRDOWN, + RK3066_PLLCON3_PWRDOWN, 0), + pll->reg_base + RK3066_PLLCON(3)); +} + +static int rockchip_rk3066_pll_is_enabled(struct clk_hw *hw) +{ + struct rockchip_clk_pll *pll = to_rockchip_clk_pll(hw); + u32 pllcon = readl(pll->reg_base + RK3066_PLLCON(3)); + + return !(pllcon & RK3066_PLLCON3_PWRDOWN); +} + +static const struct clk_ops rockchip_rk3066_pll_clk_norate_ops = { + .recalc_rate = rockchip_rk3066_pll_recalc_rate, + .enable = rockchip_rk3066_pll_enable, + .disable = rockchip_rk3066_pll_disable, + .is_enabled = rockchip_rk3066_pll_is_enabled, +}; + +static const struct clk_ops rockchip_rk3066_pll_clk_ops = { + .recalc_rate = rockchip_rk3066_pll_recalc_rate, + .round_rate = rockchip_pll_round_rate, + .set_rate = rockchip_rk3066_pll_set_rate, + .enable = rockchip_rk3066_pll_enable, + .disable = rockchip_rk3066_pll_disable, + .is_enabled = rockchip_rk3066_pll_is_enabled, +}; + +/* + * Common registering of pll clocks + */ + +struct clk *rockchip_clk_register_pll(enum rockchip_pll_type pll_type, + const char *name, const char **parent_names, u8 num_parents, + void __iomem *base, int con_offset, int grf_lock_offset, + int lock_shift, int mode_offset, int mode_shift, + struct rockchip_pll_rate_table *rate_table, + spinlock_t *lock) +{ + const char *pll_parents[3]; + struct clk_init_data init; + struct rockchip_clk_pll *pll; + struct clk_mux *pll_mux; + struct clk *pll_clk, *mux_clk; + char pll_name[20]; + int ret; + + if (num_parents != 2) { + pr_err("%s: needs two parent clocks\n", __func__); + return ERR_PTR(-EINVAL); + } + + /* name the actual pll */ + snprintf(pll_name, sizeof(pll_name), "pll_%s", name); + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = pll_name; + + /* keep all plls untouched for now */ + init.flags = CLK_IGNORE_UNUSED; + + init.parent_names = &parent_names[0]; + init.num_parents = 1; + + if (rate_table) { + int len; + + /* find count of rates in rate_table */ + for (len = 0; rate_table[len].rate != 0; ) + len++; + + pll->rate_count = len; + pll->rate_table = kmemdup(rate_table, + pll->rate_count * + sizeof(struct rockchip_pll_rate_table), + GFP_KERNEL); + WARN(!pll->rate_table, + "%s: could not allocate rate table for %s\n", + __func__, name); + } + + switch (pll_type) { + case pll_rk3066: + if (!pll->rate_table) + init.ops = &rockchip_rk3066_pll_clk_norate_ops; + else + init.ops = &rockchip_rk3066_pll_clk_ops; + break; + default: + pr_warn("%s: Unknown pll type for pll clk %s\n", + __func__, name); + } + + pll->hw.init = &init; + pll->type = pll_type; + pll->reg_base = base + con_offset; + pll->lock_offset = grf_lock_offset; + pll->lock_shift = lock_shift; + pll->lock = lock; + pll->clk_nb.notifier_call = rockchip_pll_notifier_cb; + + pll_clk = clk_register(NULL, &pll->hw); + if (IS_ERR(pll_clk)) { + pr_err("%s: failed to register pll clock %s : %ld\n", + __func__, name, PTR_ERR(pll_clk)); + mux_clk = pll_clk; + goto err_pll; + } + + ret = clk_notifier_register(pll_clk, &pll->clk_nb); + if (ret) { + pr_err("%s: failed to register clock notifier for %s : %d\n", + __func__, name, ret); + mux_clk = ERR_PTR(ret); + goto err_pll_notifier; + } + + /* create the mux on top of the real pll */ + pll->pll_mux_ops = &clk_mux_ops; + pll_mux = &pll->pll_mux; + + /* the actual muxing is xin24m, pll-output, xin32k */ + pll_parents[0] = parent_names[0]; + pll_parents[1] = pll_name; + pll_parents[2] = parent_names[1]; + + init.name = name; + init.flags = CLK_SET_RATE_PARENT; + init.ops = pll->pll_mux_ops; + init.parent_names = pll_parents; + init.num_parents = ARRAY_SIZE(pll_parents); + + pll_mux->reg = base + mode_offset; + pll_mux->shift = mode_shift; + pll_mux->mask = PLL_MODE_MASK; + pll_mux->flags = 0; + pll_mux->lock = lock; + pll_mux->hw.init = &init; + + if (pll_type == pll_rk3066) + pll_mux->flags |= CLK_MUX_HIWORD_MASK; + + mux_clk = clk_register(NULL, &pll_mux->hw); + if (IS_ERR(mux_clk)) + goto err_mux; + + return mux_clk; + +err_mux: + ret = clk_notifier_unregister(pll_clk, &pll->clk_nb); + if (ret) { + pr_err("%s: could not unregister clock notifier in error path : %d\n", + __func__, ret); + return mux_clk; + } +err_pll_notifier: + clk_unregister(pll_clk); +err_pll: + kfree(pll); + return mux_clk; +} |