diff options
Diffstat (limited to 'drivers/clk/actions/owl-pll.c')
| -rw-r--r-- | drivers/clk/actions/owl-pll.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/drivers/clk/actions/owl-pll.c b/drivers/clk/actions/owl-pll.c new file mode 100644 index 000000000..058e06d70 --- /dev/null +++ b/drivers/clk/actions/owl-pll.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// OWL pll clock driver +// +// Copyright (c) 2014 Actions Semi Inc. +// Author: David Liu <liuwei@actions-semi.com> +// +// Copyright (c) 2018 Linaro Ltd. +// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> + +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/delay.h> + +#include "owl-pll.h" + +static u32 owl_pll_calculate_mul(struct owl_pll_hw *pll_hw, unsigned long rate) +{ + u32 mul; + + mul = DIV_ROUND_CLOSEST(rate, pll_hw->bfreq); + if (mul < pll_hw->min_mul) + mul = pll_hw->min_mul; + else if (mul > pll_hw->max_mul) + mul = pll_hw->max_mul; + + return mul &= mul_mask(pll_hw); +} + +static unsigned long _get_table_rate(const struct clk_pll_table *table, + unsigned int val) +{ + const struct clk_pll_table *clkt; + + for (clkt = table; clkt->rate; clkt++) + if (clkt->val == val) + return clkt->rate; + + return 0; +} + +static const struct clk_pll_table *_get_pll_table( + const struct clk_pll_table *table, unsigned long rate) +{ + const struct clk_pll_table *clkt; + + for (clkt = table; clkt->rate; clkt++) { + if (clkt->rate == rate) { + table = clkt; + break; + } else if (clkt->rate < rate) + table = clkt; + } + + return table; +} + +static long owl_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct owl_pll *pll = hw_to_owl_pll(hw); + struct owl_pll_hw *pll_hw = &pll->pll_hw; + const struct clk_pll_table *clkt; + u32 mul; + + if (pll_hw->table) { + clkt = _get_pll_table(pll_hw->table, rate); + return clkt->rate; + } + + /* fixed frequency */ + if (pll_hw->width == 0) + return pll_hw->bfreq; + + mul = owl_pll_calculate_mul(pll_hw, rate); + + return pll_hw->bfreq * mul; +} + +static unsigned long owl_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct owl_pll *pll = hw_to_owl_pll(hw); + struct owl_pll_hw *pll_hw = &pll->pll_hw; + const struct owl_clk_common *common = &pll->common; + u32 val; + + if (pll_hw->table) { + regmap_read(common->regmap, pll_hw->reg, &val); + + val = val >> pll_hw->shift; + val &= mul_mask(pll_hw); + + return _get_table_rate(pll_hw->table, val); + } + + /* fixed frequency */ + if (pll_hw->width == 0) + return pll_hw->bfreq; + + regmap_read(common->regmap, pll_hw->reg, &val); + + val = val >> pll_hw->shift; + val &= mul_mask(pll_hw); + + return pll_hw->bfreq * val; +} + +static int owl_pll_is_enabled(struct clk_hw *hw) +{ + struct owl_pll *pll = hw_to_owl_pll(hw); + struct owl_pll_hw *pll_hw = &pll->pll_hw; + const struct owl_clk_common *common = &pll->common; + u32 reg; + + regmap_read(common->regmap, pll_hw->reg, ®); + + return !!(reg & BIT(pll_hw->bit_idx)); +} + +static void owl_pll_set(const struct owl_clk_common *common, + const struct owl_pll_hw *pll_hw, bool enable) +{ + u32 reg; + + regmap_read(common->regmap, pll_hw->reg, ®); + + if (enable) + reg |= BIT(pll_hw->bit_idx); + else + reg &= ~BIT(pll_hw->bit_idx); + + regmap_write(common->regmap, pll_hw->reg, reg); +} + +static int owl_pll_enable(struct clk_hw *hw) +{ + struct owl_pll *pll = hw_to_owl_pll(hw); + const struct owl_clk_common *common = &pll->common; + + owl_pll_set(common, &pll->pll_hw, true); + + return 0; +} + +static void owl_pll_disable(struct clk_hw *hw) +{ + struct owl_pll *pll = hw_to_owl_pll(hw); + const struct owl_clk_common *common = &pll->common; + + owl_pll_set(common, &pll->pll_hw, false); +} + +static int owl_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct owl_pll *pll = hw_to_owl_pll(hw); + struct owl_pll_hw *pll_hw = &pll->pll_hw; + const struct owl_clk_common *common = &pll->common; + const struct clk_pll_table *clkt; + u32 val, reg; + + /* fixed frequency */ + if (pll_hw->width == 0) + return 0; + + if (pll_hw->table) { + clkt = _get_pll_table(pll_hw->table, rate); + val = clkt->val; + } else { + val = owl_pll_calculate_mul(pll_hw, rate); + } + + regmap_read(common->regmap, pll_hw->reg, ®); + + reg &= ~mul_mask(pll_hw); + reg |= val << pll_hw->shift; + + regmap_write(common->regmap, pll_hw->reg, reg); + + udelay(PLL_STABILITY_WAIT_US); + + return 0; +} + +const struct clk_ops owl_pll_ops = { + .enable = owl_pll_enable, + .disable = owl_pll_disable, + .is_enabled = owl_pll_is_enabled, + .round_rate = owl_pll_round_rate, + .recalc_rate = owl_pll_recalc_rate, + .set_rate = owl_pll_set_rate, +}; |