From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/clk/at91/clk-pll.c | 379 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 379 insertions(+) create mode 100644 drivers/clk/at91/clk-pll.c (limited to 'drivers/clk/at91/clk-pll.c') diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c new file mode 100644 index 000000000..249d6a53c --- /dev/null +++ b/drivers/clk/at91/clk-pll.c @@ -0,0 +1,379 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2013 Boris BREZILLON + */ + +#include +#include +#include +#include +#include +#include + +#include "pmc.h" + +#define PLL_STATUS_MASK(id) (1 << (1 + (id))) +#define PLL_REG(id) (AT91_CKGR_PLLAR + ((id) * 4)) +#define PLL_DIV_MASK 0xff +#define PLL_DIV_MAX PLL_DIV_MASK +#define PLL_DIV(reg) ((reg) & PLL_DIV_MASK) +#define PLL_MUL(reg, layout) (((reg) >> (layout)->mul_shift) & \ + (layout)->mul_mask) +#define PLL_MUL_MIN 2 +#define PLL_MUL_MASK(layout) ((layout)->mul_mask) +#define PLL_MUL_MAX(layout) (PLL_MUL_MASK(layout) + 1) +#define PLL_ICPR_SHIFT(id) ((id) * 16) +#define PLL_ICPR_MASK(id) (0xffff << PLL_ICPR_SHIFT(id)) +#define PLL_MAX_COUNT 0x3f +#define PLL_COUNT_SHIFT 8 +#define PLL_OUT_SHIFT 14 +#define PLL_MAX_ID 1 + +#define to_clk_pll(hw) container_of(hw, struct clk_pll, hw) + +struct clk_pll { + struct clk_hw hw; + struct regmap *regmap; + u8 id; + u8 div; + u8 range; + u16 mul; + const struct clk_pll_layout *layout; + const struct clk_pll_characteristics *characteristics; + struct at91_clk_pms pms; +}; + +static inline bool clk_pll_ready(struct regmap *regmap, int id) +{ + unsigned int status; + + regmap_read(regmap, AT91_PMC_SR, &status); + + return status & PLL_STATUS_MASK(id) ? 1 : 0; +} + +static int clk_pll_prepare(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + struct regmap *regmap = pll->regmap; + const struct clk_pll_layout *layout = pll->layout; + const struct clk_pll_characteristics *characteristics = + pll->characteristics; + u8 id = pll->id; + u32 mask = PLL_STATUS_MASK(id); + int offset = PLL_REG(id); + u8 out = 0; + unsigned int pllr; + unsigned int status; + u8 div; + u16 mul; + + regmap_read(regmap, offset, &pllr); + div = PLL_DIV(pllr); + mul = PLL_MUL(pllr, layout); + + regmap_read(regmap, AT91_PMC_SR, &status); + if ((status & mask) && + (div == pll->div && mul == pll->mul)) + return 0; + + if (characteristics->out) + out = characteristics->out[pll->range]; + + if (characteristics->icpll) + regmap_update_bits(regmap, AT91_PMC_PLLICPR, PLL_ICPR_MASK(id), + characteristics->icpll[pll->range] << PLL_ICPR_SHIFT(id)); + + regmap_update_bits(regmap, offset, layout->pllr_mask, + pll->div | (PLL_MAX_COUNT << PLL_COUNT_SHIFT) | + (out << PLL_OUT_SHIFT) | + ((pll->mul & layout->mul_mask) << layout->mul_shift)); + + while (!clk_pll_ready(regmap, pll->id)) + cpu_relax(); + + return 0; +} + +static int clk_pll_is_prepared(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + + return clk_pll_ready(pll->regmap, pll->id); +} + +static void clk_pll_unprepare(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + unsigned int mask = pll->layout->pllr_mask; + + regmap_update_bits(pll->regmap, PLL_REG(pll->id), mask, ~mask); +} + +static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + + if (!pll->div || !pll->mul) + return 0; + + return (parent_rate / pll->div) * (pll->mul + 1); +} + +static long clk_pll_get_best_div_mul(struct clk_pll *pll, unsigned long rate, + unsigned long parent_rate, + u32 *div, u32 *mul, + u32 *index) { + const struct clk_pll_layout *layout = pll->layout; + const struct clk_pll_characteristics *characteristics = + pll->characteristics; + unsigned long bestremainder = ULONG_MAX; + unsigned long maxdiv, mindiv, tmpdiv; + long bestrate = -ERANGE; + unsigned long bestdiv; + unsigned long bestmul; + int i = 0; + + /* Check if parent_rate is a valid input rate */ + if (parent_rate < characteristics->input.min) + return -ERANGE; + + /* + * Calculate minimum divider based on the minimum multiplier, the + * parent_rate and the requested rate. + * Should always be 2 according to the input and output characteristics + * of the PLL blocks. + */ + mindiv = (parent_rate * PLL_MUL_MIN) / rate; + if (!mindiv) + mindiv = 1; + + if (parent_rate > characteristics->input.max) { + tmpdiv = DIV_ROUND_UP(parent_rate, characteristics->input.max); + if (tmpdiv > PLL_DIV_MAX) + return -ERANGE; + + if (tmpdiv > mindiv) + mindiv = tmpdiv; + } + + /* + * Calculate the maximum divider which is limited by PLL register + * layout (limited by the MUL or DIV field size). + */ + maxdiv = DIV_ROUND_UP(parent_rate * PLL_MUL_MAX(layout), rate); + if (maxdiv > PLL_DIV_MAX) + maxdiv = PLL_DIV_MAX; + + /* + * Iterate over the acceptable divider values to find the best + * divider/multiplier pair (the one that generates the closest + * rate to the requested one). + */ + for (tmpdiv = mindiv; tmpdiv <= maxdiv; tmpdiv++) { + unsigned long remainder; + unsigned long tmprate; + unsigned long tmpmul; + + /* + * Calculate the multiplier associated with the current + * divider that provide the closest rate to the requested one. + */ + tmpmul = DIV_ROUND_CLOSEST(rate, parent_rate / tmpdiv); + tmprate = (parent_rate / tmpdiv) * tmpmul; + if (tmprate > rate) + remainder = tmprate - rate; + else + remainder = rate - tmprate; + + /* + * Compare the remainder with the best remainder found until + * now and elect a new best multiplier/divider pair if the + * current remainder is smaller than the best one. + */ + if (remainder < bestremainder) { + bestremainder = remainder; + bestdiv = tmpdiv; + bestmul = tmpmul; + bestrate = tmprate; + } + + /* + * We've found a perfect match! + * Stop searching now and use this multiplier/divider pair. + */ + if (!remainder) + break; + } + + /* We haven't found any multiplier/divider pair => return -ERANGE */ + if (bestrate < 0) + return bestrate; + + /* Check if bestrate is a valid output rate */ + for (i = 0; i < characteristics->num_output; i++) { + if (bestrate >= characteristics->output[i].min && + bestrate <= characteristics->output[i].max) + break; + } + + if (i >= characteristics->num_output) + return -ERANGE; + + if (div) + *div = bestdiv; + if (mul) + *mul = bestmul - 1; + if (index) + *index = i; + + return bestrate; +} + +static long clk_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + + return clk_pll_get_best_div_mul(pll, rate, *parent_rate, + NULL, NULL, NULL); +} + +static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_pll *pll = to_clk_pll(hw); + long ret; + u32 div; + u32 mul; + u32 index; + + ret = clk_pll_get_best_div_mul(pll, rate, parent_rate, + &div, &mul, &index); + if (ret < 0) + return ret; + + pll->range = index; + pll->div = div; + pll->mul = mul; + + return 0; +} + +static int clk_pll_save_context(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + struct clk_hw *parent_hw = clk_hw_get_parent(hw); + + pll->pms.parent_rate = clk_hw_get_rate(parent_hw); + pll->pms.rate = clk_pll_recalc_rate(&pll->hw, pll->pms.parent_rate); + pll->pms.status = clk_pll_ready(pll->regmap, PLL_REG(pll->id)); + + return 0; +} + +static void clk_pll_restore_context(struct clk_hw *hw) +{ + struct clk_pll *pll = to_clk_pll(hw); + unsigned long calc_rate; + unsigned int pllr, pllr_out, pllr_count; + u8 out = 0; + + if (pll->characteristics->out) + out = pll->characteristics->out[pll->range]; + + regmap_read(pll->regmap, PLL_REG(pll->id), &pllr); + + calc_rate = (pll->pms.parent_rate / PLL_DIV(pllr)) * + (PLL_MUL(pllr, pll->layout) + 1); + pllr_count = (pllr >> PLL_COUNT_SHIFT) & PLL_MAX_COUNT; + pllr_out = (pllr >> PLL_OUT_SHIFT) & out; + + if (pll->pms.rate != calc_rate || + pll->pms.status != clk_pll_ready(pll->regmap, PLL_REG(pll->id)) || + pllr_count != PLL_MAX_COUNT || + (out && pllr_out != out)) + pr_warn("PLLAR was not configured properly by firmware\n"); +} + +static const struct clk_ops pll_ops = { + .prepare = clk_pll_prepare, + .unprepare = clk_pll_unprepare, + .is_prepared = clk_pll_is_prepared, + .recalc_rate = clk_pll_recalc_rate, + .round_rate = clk_pll_round_rate, + .set_rate = clk_pll_set_rate, + .save_context = clk_pll_save_context, + .restore_context = clk_pll_restore_context, +}; + +struct clk_hw * __init +at91_clk_register_pll(struct regmap *regmap, const char *name, + const char *parent_name, u8 id, + const struct clk_pll_layout *layout, + const struct clk_pll_characteristics *characteristics) +{ + struct clk_pll *pll; + struct clk_hw *hw; + struct clk_init_data init; + int offset = PLL_REG(id); + unsigned int pllr; + int ret; + + if (id > PLL_MAX_ID) + return ERR_PTR(-EINVAL); + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &pll_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = CLK_SET_RATE_GATE; + + pll->id = id; + pll->hw.init = &init; + pll->layout = layout; + pll->characteristics = characteristics; + pll->regmap = regmap; + regmap_read(regmap, offset, &pllr); + pll->div = PLL_DIV(pllr); + pll->mul = PLL_MUL(pllr, layout); + + hw = &pll->hw; + ret = clk_hw_register(NULL, &pll->hw); + if (ret) { + kfree(pll); + hw = ERR_PTR(ret); + } + + return hw; +} + + +const struct clk_pll_layout at91rm9200_pll_layout = { + .pllr_mask = 0x7FFFFFF, + .mul_shift = 16, + .mul_mask = 0x7FF, +}; + +const struct clk_pll_layout at91sam9g45_pll_layout = { + .pllr_mask = 0xFFFFFF, + .mul_shift = 16, + .mul_mask = 0xFF, +}; + +const struct clk_pll_layout at91sam9g20_pllb_layout = { + .pllr_mask = 0x3FFFFF, + .mul_shift = 16, + .mul_mask = 0x3F, +}; + +const struct clk_pll_layout sama5d3_pll_layout = { + .pllr_mask = 0x1FFFFFF, + .mul_shift = 18, + .mul_mask = 0x7F, +}; -- cgit v1.2.3