diff options
Diffstat (limited to 'drivers/clk/qcom/clk-hfpll.c')
| -rw-r--r-- | drivers/clk/qcom/clk-hfpll.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-hfpll.c b/drivers/clk/qcom/clk-hfpll.c new file mode 100644 index 000000000000..3c04805f2a55 --- /dev/null +++ b/drivers/clk/qcom/clk-hfpll.c @@ -0,0 +1,244 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018, The Linux Foundation. All rights reserved. + +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/regmap.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/clk-provider.h> +#include <linux/spinlock.h> + +#include "clk-regmap.h" +#include "clk-hfpll.h" + +#define PLL_OUTCTRL BIT(0) +#define PLL_BYPASSNL BIT(1) +#define PLL_RESET_N BIT(2) + +/* Initialize a HFPLL at a given rate and enable it. */ +static void __clk_hfpll_init_once(struct clk_hw *hw) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + + if (likely(h->init_done)) + return; + + /* Configure PLL parameters for integer mode. */ + if (hd->config_val) + regmap_write(regmap, hd->config_reg, hd->config_val); + regmap_write(regmap, hd->m_reg, 0); + regmap_write(regmap, hd->n_reg, 1); + + if (hd->user_reg) { + u32 regval = hd->user_val; + unsigned long rate; + + rate = clk_hw_get_rate(hw); + + /* Pick the right VCO. */ + if (hd->user_vco_mask && rate > hd->low_vco_max_rate) + regval |= hd->user_vco_mask; + regmap_write(regmap, hd->user_reg, regval); + } + + if (hd->droop_reg) + regmap_write(regmap, hd->droop_reg, hd->droop_val); + + h->init_done = true; +} + +static void __clk_hfpll_enable(struct clk_hw *hw) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + u32 val; + + __clk_hfpll_init_once(hw); + + /* Disable PLL bypass mode. */ + regmap_update_bits(regmap, hd->mode_reg, PLL_BYPASSNL, PLL_BYPASSNL); + + /* + * H/W requires a 5us delay between disabling the bypass and + * de-asserting the reset. Delay 10us just to be safe. + */ + udelay(10); + + /* De-assert active-low PLL reset. */ + regmap_update_bits(regmap, hd->mode_reg, PLL_RESET_N, PLL_RESET_N); + + /* Wait for PLL to lock. */ + if (hd->status_reg) { + do { + regmap_read(regmap, hd->status_reg, &val); + } while (!(val & BIT(hd->lock_bit))); + } else { + udelay(60); + } + + /* Enable PLL output. */ + regmap_update_bits(regmap, hd->mode_reg, PLL_OUTCTRL, PLL_OUTCTRL); +} + +/* Enable an already-configured HFPLL. */ +static int clk_hfpll_enable(struct clk_hw *hw) +{ + unsigned long flags; + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + u32 mode; + + spin_lock_irqsave(&h->lock, flags); + regmap_read(regmap, hd->mode_reg, &mode); + if (!(mode & (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL))) + __clk_hfpll_enable(hw); + spin_unlock_irqrestore(&h->lock, flags); + + return 0; +} + +static void __clk_hfpll_disable(struct clk_hfpll *h) +{ + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + + /* + * Disable the PLL output, disable test mode, enable the bypass mode, + * and assert the reset. + */ + regmap_update_bits(regmap, hd->mode_reg, + PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL, 0); +} + +static void clk_hfpll_disable(struct clk_hw *hw) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + unsigned long flags; + + spin_lock_irqsave(&h->lock, flags); + __clk_hfpll_disable(h); + spin_unlock_irqrestore(&h->lock, flags); +} + +static long clk_hfpll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + unsigned long rrate; + + rate = clamp(rate, hd->min_rate, hd->max_rate); + + rrate = DIV_ROUND_UP(rate, *parent_rate) * *parent_rate; + if (rrate > hd->max_rate) + rrate -= *parent_rate; + + return rrate; +} + +/* + * For optimization reasons, assumes no downstream clocks are actively using + * it. + */ +static int clk_hfpll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + unsigned long flags; + u32 l_val, val; + bool enabled; + + l_val = rate / parent_rate; + + spin_lock_irqsave(&h->lock, flags); + + enabled = __clk_is_enabled(hw->clk); + if (enabled) + __clk_hfpll_disable(h); + + /* Pick the right VCO. */ + if (hd->user_reg && hd->user_vco_mask) { + regmap_read(regmap, hd->user_reg, &val); + if (rate <= hd->low_vco_max_rate) + val &= ~hd->user_vco_mask; + else + val |= hd->user_vco_mask; + regmap_write(regmap, hd->user_reg, val); + } + + regmap_write(regmap, hd->l_reg, l_val); + + if (enabled) + __clk_hfpll_enable(hw); + + spin_unlock_irqrestore(&h->lock, flags); + + return 0; +} + +static unsigned long clk_hfpll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + u32 l_val; + + regmap_read(regmap, hd->l_reg, &l_val); + + return l_val * parent_rate; +} + +static void clk_hfpll_init(struct clk_hw *hw) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + u32 mode, status; + + regmap_read(regmap, hd->mode_reg, &mode); + if (mode != (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)) { + __clk_hfpll_init_once(hw); + return; + } + + if (hd->status_reg) { + regmap_read(regmap, hd->status_reg, &status); + if (!(status & BIT(hd->lock_bit))) { + WARN(1, "HFPLL %s is ON, but not locked!\n", + __clk_get_name(hw->clk)); + clk_hfpll_disable(hw); + __clk_hfpll_init_once(hw); + } + } +} + +static int hfpll_is_enabled(struct clk_hw *hw) +{ + struct clk_hfpll *h = to_clk_hfpll(hw); + struct hfpll_data const *hd = h->d; + struct regmap *regmap = h->clkr.regmap; + u32 mode; + + regmap_read(regmap, hd->mode_reg, &mode); + mode &= 0x7; + return mode == (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL); +} + +const struct clk_ops clk_ops_hfpll = { + .enable = clk_hfpll_enable, + .disable = clk_hfpll_disable, + .is_enabled = hfpll_is_enabled, + .round_rate = clk_hfpll_round_rate, + .set_rate = clk_hfpll_set_rate, + .recalc_rate = clk_hfpll_recalc_rate, + .init = clk_hfpll_init, +}; +EXPORT_SYMBOL_GPL(clk_ops_hfpll); |