diff options
Diffstat (limited to 'drivers/clk/sprd/pll.c')
| -rw-r--r-- | drivers/clk/sprd/pll.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/drivers/clk/sprd/pll.c b/drivers/clk/sprd/pll.c new file mode 100644 index 000000000..13a322b25 --- /dev/null +++ b/drivers/clk/sprd/pll.c @@ -0,0 +1,269 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Spreadtrum pll clock driver +// +// Copyright (C) 2015~2017 Spreadtrum, Inc. +// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com> + +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include "pll.h" + +#define CLK_PLL_1M 1000000 +#define CLK_PLL_10M (CLK_PLL_1M * 10) + +#define pindex(pll, member) \ + (pll->factors[member].shift / (8 * sizeof(pll->regs_num))) + +#define pshift(pll, member) \ + (pll->factors[member].shift % (8 * sizeof(pll->regs_num))) + +#define pwidth(pll, member) \ + pll->factors[member].width + +#define pmask(pll, member) \ + ((pwidth(pll, member)) ? \ + GENMASK(pwidth(pll, member) + pshift(pll, member) - 1, \ + pshift(pll, member)) : 0) + +#define pinternal(pll, cfg, member) \ + (cfg[pindex(pll, member)] & pmask(pll, member)) + +#define pinternal_val(pll, cfg, member) \ + (pinternal(pll, cfg, member) >> pshift(pll, member)) + +static inline unsigned int +sprd_pll_read(const struct sprd_pll *pll, u8 index) +{ + const struct sprd_clk_common *common = &pll->common; + unsigned int val = 0; + + if (WARN_ON(index >= pll->regs_num)) + return 0; + + regmap_read(common->regmap, common->reg + index * 4, &val); + + return val; +} + +static inline void +sprd_pll_write(const struct sprd_pll *pll, u8 index, + u32 msk, u32 val) +{ + const struct sprd_clk_common *common = &pll->common; + unsigned int offset, reg; + int ret = 0; + + if (WARN_ON(index >= pll->regs_num)) + return; + + offset = common->reg + index * 4; + ret = regmap_read(common->regmap, offset, ®); + if (!ret) + regmap_write(common->regmap, offset, (reg & ~msk) | val); +} + +static unsigned long pll_get_refin(const struct sprd_pll *pll) +{ + u32 shift, mask, index, refin_id = 3; + const unsigned long refin[4] = { 2, 4, 13, 26 }; + + if (pwidth(pll, PLL_REFIN)) { + index = pindex(pll, PLL_REFIN); + shift = pshift(pll, PLL_REFIN); + mask = pmask(pll, PLL_REFIN); + refin_id = (sprd_pll_read(pll, index) & mask) >> shift; + if (refin_id > 3) + refin_id = 3; + } + + return refin[refin_id]; +} + +static u32 pll_get_ibias(u64 rate, const u64 *table) +{ + u32 i, num = table[0]; + + /* table[0] indicates the number of items in this table */ + for (i = 0; i < num; i++) + if (rate <= table[i + 1]) + break; + + return i == num ? num - 1 : i; +} + +static unsigned long _sprd_pll_recalc_rate(const struct sprd_pll *pll, + unsigned long parent_rate) +{ + u32 *cfg; + u32 i, mask, regs_num = pll->regs_num; + unsigned long rate, nint, kint = 0; + u64 refin; + u16 k1, k2; + + cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL); + if (!cfg) + return parent_rate; + + for (i = 0; i < regs_num; i++) + cfg[i] = sprd_pll_read(pll, i); + + refin = pll_get_refin(pll); + + if (pinternal(pll, cfg, PLL_PREDIV)) + refin = refin * 2; + + if (pwidth(pll, PLL_POSTDIV) && + ((pll->fflag == 1 && pinternal(pll, cfg, PLL_POSTDIV)) || + (!pll->fflag && !pinternal(pll, cfg, PLL_POSTDIV)))) + refin = refin / 2; + + if (!pinternal(pll, cfg, PLL_DIV_S)) { + rate = refin * pinternal_val(pll, cfg, PLL_N) * CLK_PLL_10M; + } else { + nint = pinternal_val(pll, cfg, PLL_NINT); + if (pinternal(pll, cfg, PLL_SDM_EN)) + kint = pinternal_val(pll, cfg, PLL_KINT); + + mask = pmask(pll, PLL_KINT); + + k1 = pll->k1; + k2 = pll->k2; + rate = DIV_ROUND_CLOSEST_ULL(refin * kint * k1, + ((mask >> __ffs(mask)) + 1)) * + k2 + refin * nint * CLK_PLL_1M; + } + + kfree(cfg); + return rate; +} + +#define SPRD_PLL_WRITE_CHECK(pll, i, mask, val) \ + (((sprd_pll_read(pll, i) & mask) == val) ? 0 : (-EFAULT)) + +static int _sprd_pll_set_rate(const struct sprd_pll *pll, + unsigned long rate, + unsigned long parent_rate) +{ + struct reg_cfg *cfg; + int ret = 0; + u32 mask, shift, width, ibias_val, index; + u32 regs_num = pll->regs_num, i = 0; + unsigned long kint, nint; + u64 tmp, refin, fvco = rate; + + cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL); + if (!cfg) + return -ENOMEM; + + refin = pll_get_refin(pll); + + mask = pmask(pll, PLL_PREDIV); + index = pindex(pll, PLL_PREDIV); + width = pwidth(pll, PLL_PREDIV); + if (width && (sprd_pll_read(pll, index) & mask)) + refin = refin * 2; + + mask = pmask(pll, PLL_POSTDIV); + index = pindex(pll, PLL_POSTDIV); + width = pwidth(pll, PLL_POSTDIV); + cfg[index].msk = mask; + if (width && ((pll->fflag == 1 && fvco <= pll->fvco) || + (pll->fflag == 0 && fvco > pll->fvco))) + cfg[index].val |= mask; + + if (width && fvco <= pll->fvco) + fvco = fvco * 2; + + mask = pmask(pll, PLL_DIV_S); + index = pindex(pll, PLL_DIV_S); + cfg[index].val |= mask; + cfg[index].msk |= mask; + + mask = pmask(pll, PLL_SDM_EN); + index = pindex(pll, PLL_SDM_EN); + cfg[index].val |= mask; + cfg[index].msk |= mask; + + nint = do_div(fvco, refin * CLK_PLL_1M); + mask = pmask(pll, PLL_NINT); + index = pindex(pll, PLL_NINT); + shift = pshift(pll, PLL_NINT); + cfg[index].val |= (nint << shift) & mask; + cfg[index].msk |= mask; + + mask = pmask(pll, PLL_KINT); + index = pindex(pll, PLL_KINT); + width = pwidth(pll, PLL_KINT); + shift = pshift(pll, PLL_KINT); + tmp = fvco - refin * nint * CLK_PLL_1M; + tmp = do_div(tmp, 10000) * ((mask >> shift) + 1); + kint = DIV_ROUND_CLOSEST_ULL(tmp, refin * 100); + cfg[index].val |= (kint << shift) & mask; + cfg[index].msk |= mask; + + ibias_val = pll_get_ibias(fvco, pll->itable); + + mask = pmask(pll, PLL_IBIAS); + index = pindex(pll, PLL_IBIAS); + shift = pshift(pll, PLL_IBIAS); + cfg[index].val |= ibias_val << shift & mask; + cfg[index].msk |= mask; + + for (i = 0; i < regs_num; i++) { + if (cfg[i].msk) { + sprd_pll_write(pll, i, cfg[i].msk, cfg[i].val); + ret |= SPRD_PLL_WRITE_CHECK(pll, i, cfg[i].msk, + cfg[i].val); + } + } + + if (!ret) + udelay(pll->udelay); + + kfree(cfg); + return ret; +} + +static unsigned long sprd_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sprd_pll *pll = hw_to_sprd_pll(hw); + + return _sprd_pll_recalc_rate(pll, parent_rate); +} + +static int sprd_pll_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + struct sprd_pll *pll = hw_to_sprd_pll(hw); + + return _sprd_pll_set_rate(pll, rate, parent_rate); +} + +static int sprd_pll_clk_prepare(struct clk_hw *hw) +{ + struct sprd_pll *pll = hw_to_sprd_pll(hw); + + udelay(pll->udelay); + + return 0; +} + +static long sprd_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + return rate; +} + +const struct clk_ops sprd_pll_ops = { + .prepare = sprd_pll_clk_prepare, + .recalc_rate = sprd_pll_recalc_rate, + .round_rate = sprd_pll_round_rate, + .set_rate = sprd_pll_set_rate, +}; +EXPORT_SYMBOL_GPL(sprd_pll_ops); |