diff options
author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-04-02 14:50:54 +0200 |
---|---|---|
committer | Stephen Boyd <sboyd@kernel.org> | 2019-04-25 21:34:06 +0200 |
commit | a436c2a447e59740e8bc5c604abac33419099673 (patch) | |
tree | dcbabdd4516f54caeb5bd438a3b3c6c1459fa215 /drivers/clk/at91 | |
parent | clk: at91: master: Add sam9x60 support (diff) | |
download | linux-a436c2a447e59740e8bc5c604abac33419099673.tar.xz linux-a436c2a447e59740e8bc5c604abac33419099673.zip |
clk: at91: add sam9x60 PLL driver
The PLLs on the sam9x60 (PLLA and USB PLL) use a different register set and
programming model than the previous SoCs.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk/at91')
-rw-r--r-- | drivers/clk/at91/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/at91/clk-sam9x60-pll.c | 330 | ||||
-rw-r--r-- | drivers/clk/at91/pmc.h | 6 |
3 files changed, 337 insertions, 0 deletions
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index c75df1cad60e..0a30fc8dfcb0 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_HAVE_AT91_SMD) += clk-smd.o obj-$(CONFIG_HAVE_AT91_H32MX) += clk-h32mx.o obj-$(CONFIG_HAVE_AT91_GENERATED_CLK) += clk-generated.o obj-$(CONFIG_HAVE_AT91_I2S_MUX_CLK) += clk-i2s-mux.o +obj-$(CONFIG_HAVE_AT91_SAM9X60_PLL) += clk-sam9x60-pll.o obj-$(CONFIG_SOC_AT91SAM9) += at91sam9260.o at91sam9rl.o at91sam9x5.o obj-$(CONFIG_SOC_SAMA5D4) += sama5d4.o obj-$(CONFIG_SOC_SAMA5D2) += sama5d2.o diff --git a/drivers/clk/at91/clk-sam9x60-pll.c b/drivers/clk/at91/clk-sam9x60-pll.c new file mode 100644 index 000000000000..34b817825b22 --- /dev/null +++ b/drivers/clk/at91/clk-sam9x60-pll.c @@ -0,0 +1,330 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2019 Microchip Technology Inc. + * + */ + +#include <linux/bitfield.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/mfd/syscon.h> +#include <linux/regmap.h> + +#include "pmc.h" + +#define PMC_PLL_CTRL0 0xc +#define PMC_PLL_CTRL0_DIV_MSK GENMASK(7, 0) +#define PMC_PLL_CTRL0_ENPLL BIT(28) +#define PMC_PLL_CTRL0_ENPLLCK BIT(29) +#define PMC_PLL_CTRL0_ENLOCK BIT(31) + +#define PMC_PLL_CTRL1 0x10 +#define PMC_PLL_CTRL1_FRACR_MSK GENMASK(21, 0) +#define PMC_PLL_CTRL1_MUL_MSK GENMASK(30, 24) + +#define PMC_PLL_ACR 0x18 +#define PMC_PLL_ACR_DEFAULT 0x1b040010UL +#define PMC_PLL_ACR_UTMIVR BIT(12) +#define PMC_PLL_ACR_UTMIBG BIT(13) +#define PMC_PLL_ACR_LOOP_FILTER_MSK GENMASK(31, 24) + +#define PMC_PLL_UPDT 0x1c +#define PMC_PLL_UPDT_UPDATE BIT(8) + +#define PMC_PLL_ISR0 0xec + +#define PLL_DIV_MAX (FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, UINT_MAX) + 1) +#define UPLL_DIV 2 +#define PLL_MUL_MAX (FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, UINT_MAX) + 1) + +#define PLL_MAX_ID 1 + +struct sam9x60_pll { + struct clk_hw hw; + struct regmap *regmap; + spinlock_t *lock; + const struct clk_pll_characteristics *characteristics; + u32 frac; + u8 id; + u8 div; + u16 mul; +}; + +#define to_sam9x60_pll(hw) container_of(hw, struct sam9x60_pll, hw) + +static inline bool sam9x60_pll_ready(struct regmap *regmap, int id) +{ + unsigned int status; + + regmap_read(regmap, PMC_PLL_ISR0, &status); + + return !!(status & BIT(id)); +} + +static int sam9x60_pll_prepare(struct clk_hw *hw) +{ + struct sam9x60_pll *pll = to_sam9x60_pll(hw); + struct regmap *regmap = pll->regmap; + unsigned long flags; + u8 div; + u16 mul; + u32 val; + + spin_lock_irqsave(pll->lock, flags); + regmap_write(regmap, PMC_PLL_UPDT, pll->id); + + regmap_read(regmap, PMC_PLL_CTRL0, &val); + div = FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, val); + + regmap_read(regmap, PMC_PLL_CTRL1, &val); + mul = FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, val); + + if (sam9x60_pll_ready(regmap, pll->id) && + (div == pll->div && mul == pll->mul)) { + spin_unlock_irqrestore(pll->lock, flags); + return 0; + } + + /* Recommended value for PMC_PLL_ACR */ + val = PMC_PLL_ACR_DEFAULT; + regmap_write(regmap, PMC_PLL_ACR, val); + + regmap_write(regmap, PMC_PLL_CTRL1, + FIELD_PREP(PMC_PLL_CTRL1_MUL_MSK, pll->mul)); + + if (pll->characteristics->upll) { + /* Enable the UTMI internal bandgap */ + val |= PMC_PLL_ACR_UTMIBG; + regmap_write(regmap, PMC_PLL_ACR, val); + + udelay(10); + + /* Enable the UTMI internal regulator */ + val |= PMC_PLL_ACR_UTMIVR; + regmap_write(regmap, PMC_PLL_ACR, val); + + udelay(10); + } + + regmap_update_bits(regmap, PMC_PLL_UPDT, + PMC_PLL_UPDT_UPDATE, PMC_PLL_UPDT_UPDATE); + + regmap_write(regmap, PMC_PLL_CTRL0, + PMC_PLL_CTRL0_ENLOCK | PMC_PLL_CTRL0_ENPLL | + PMC_PLL_CTRL0_ENPLLCK | pll->div); + + regmap_update_bits(regmap, PMC_PLL_UPDT, + PMC_PLL_UPDT_UPDATE, PMC_PLL_UPDT_UPDATE); + + while (!sam9x60_pll_ready(regmap, pll->id)) + cpu_relax(); + + spin_unlock_irqrestore(pll->lock, flags); + + return 0; +} + +static int sam9x60_pll_is_prepared(struct clk_hw *hw) +{ + struct sam9x60_pll *pll = to_sam9x60_pll(hw); + + return sam9x60_pll_ready(pll->regmap, pll->id); +} + +static void sam9x60_pll_unprepare(struct clk_hw *hw) +{ + struct sam9x60_pll *pll = to_sam9x60_pll(hw); + unsigned long flags; + + spin_lock_irqsave(pll->lock, flags); + + regmap_write(pll->regmap, PMC_PLL_UPDT, pll->id); + + regmap_update_bits(pll->regmap, PMC_PLL_CTRL0, + PMC_PLL_CTRL0_ENPLLCK, 0); + + regmap_update_bits(pll->regmap, PMC_PLL_UPDT, + PMC_PLL_UPDT_UPDATE, PMC_PLL_UPDT_UPDATE); + + regmap_update_bits(pll->regmap, PMC_PLL_CTRL0, PMC_PLL_CTRL0_ENPLL, 0); + + if (pll->characteristics->upll) + regmap_update_bits(pll->regmap, PMC_PLL_ACR, + PMC_PLL_ACR_UTMIBG | PMC_PLL_ACR_UTMIVR, 0); + + regmap_update_bits(pll->regmap, PMC_PLL_UPDT, + PMC_PLL_UPDT_UPDATE, PMC_PLL_UPDT_UPDATE); + + spin_unlock_irqrestore(pll->lock, flags); +} + +static unsigned long sam9x60_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sam9x60_pll *pll = to_sam9x60_pll(hw); + + return (parent_rate * (pll->mul + 1)) / (pll->div + 1); +} + +static long sam9x60_pll_get_best_div_mul(struct sam9x60_pll *pll, + unsigned long rate, + unsigned long parent_rate, + bool update) +{ + const struct clk_pll_characteristics *characteristics = + pll->characteristics; + unsigned long bestremainder = ULONG_MAX; + unsigned long maxdiv, mindiv, tmpdiv; + long bestrate = -ERANGE; + unsigned long bestdiv = 0; + unsigned long bestmul = 0; + unsigned long bestfrac = 0; + + if (rate < characteristics->output[0].min || + rate > characteristics->output[0].max) + return -ERANGE; + + if (!pll->characteristics->upll) { + mindiv = parent_rate / rate; + if (mindiv < 2) + mindiv = 2; + + maxdiv = DIV_ROUND_UP(parent_rate * PLL_MUL_MAX, rate); + if (maxdiv > PLL_DIV_MAX) + maxdiv = PLL_DIV_MAX; + } else { + mindiv = maxdiv = UPLL_DIV; + } + + for (tmpdiv = mindiv; tmpdiv <= maxdiv; tmpdiv++) { + unsigned long remainder; + unsigned long tmprate; + unsigned long tmpmul; + unsigned long tmpfrac = 0; + + /* + * Calculate the multiplier associated with the current + * divider that provide the closest rate to the requested one. + */ + tmpmul = mult_frac(rate, tmpdiv, parent_rate); + tmprate = mult_frac(parent_rate, tmpmul, tmpdiv); + remainder = rate - tmprate; + + if (remainder) { + tmpfrac = DIV_ROUND_CLOSEST_ULL((u64)remainder * tmpdiv * (1 << 22), + parent_rate); + + tmprate += DIV_ROUND_CLOSEST_ULL((u64)tmpfrac * parent_rate, + tmpdiv * (1 << 22)); + + 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; + bestfrac = tmpfrac; + } + + /* We've found a perfect match! */ + if (!remainder) + break; + } + + /* Check if bestrate is a valid output rate */ + if (bestrate < characteristics->output[0].min && + bestrate > characteristics->output[0].max) + return -ERANGE; + + if (update) { + pll->div = bestdiv - 1; + pll->mul = bestmul - 1; + pll->frac = bestfrac; + } + + return bestrate; +} + +static long sam9x60_pll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct sam9x60_pll *pll = to_sam9x60_pll(hw); + + return sam9x60_pll_get_best_div_mul(pll, rate, *parent_rate, false); +} + +static int sam9x60_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sam9x60_pll *pll = to_sam9x60_pll(hw); + + return sam9x60_pll_get_best_div_mul(pll, rate, parent_rate, true); +} + +static const struct clk_ops pll_ops = { + .prepare = sam9x60_pll_prepare, + .unprepare = sam9x60_pll_unprepare, + .is_prepared = sam9x60_pll_is_prepared, + .recalc_rate = sam9x60_pll_recalc_rate, + .round_rate = sam9x60_pll_round_rate, + .set_rate = sam9x60_pll_set_rate, +}; + +struct clk_hw * __init +sam9x60_clk_register_pll(struct regmap *regmap, spinlock_t *lock, + const char *name, const char *parent_name, u8 id, + const struct clk_pll_characteristics *characteristics) +{ + struct sam9x60_pll *pll; + struct clk_hw *hw; + struct clk_init_data init; + 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->characteristics = characteristics; + pll->regmap = regmap; + pll->lock = lock; + + regmap_write(regmap, PMC_PLL_UPDT, id); + regmap_read(regmap, PMC_PLL_CTRL0, &pllr); + pll->div = FIELD_GET(PMC_PLL_CTRL0_DIV_MSK, pllr); + regmap_read(regmap, PMC_PLL_CTRL1, &pllr); + pll->mul = FIELD_GET(PMC_PLL_CTRL1_MUL_MSK, pllr); + + hw = &pll->hw; + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(pll); + hw = ERR_PTR(ret); + } + + return hw; +} + diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index 4a30c20f17f1..fb9e9c4cdc8d 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -69,6 +69,7 @@ struct clk_pll_characteristics { struct clk_range *output; u16 *icpll; u8 *out; + u8 upll : 1; }; struct clk_programmable_layout { @@ -170,6 +171,11 @@ at91_clk_register_plldiv(struct regmap *regmap, const char *name, const char *parent_name); struct clk_hw * __init +sam9x60_clk_register_pll(struct regmap *regmap, spinlock_t *lock, + const char *name, const char *parent_name, u8 id, + const struct clk_pll_characteristics *characteristics); + +struct clk_hw * __init at91_clk_register_programmable(struct regmap *regmap, const char *name, const char **parent_names, u8 num_parents, u8 id, const struct clk_programmable_layout *layout); |