From 1b26cb8a77a49d8f8b5b723ef1db4cd6d2434dfc Mon Sep 17 00:00:00 2001 From: Peng Fan Date: Mon, 28 Feb 2022 10:09:07 +0800 Subject: [PATCH] clk: imx: support fracn gppll This PLL module is a Fractional-N synthesizer, supporting 30-bit numerator and denominator. Numerator is a signed number. It has feature to adjust fractional portion of feedback divider dynamically. This fracn gppll is used in i.MX93. Reviewed-by: Abel Vesa Reviewed-by: Sascha Hauer Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/20220228020908.2810346-5-peng.fan@oss.nxp.com Signed-off-by: Abel Vesa --- drivers/clk/imx/Makefile | 1 + drivers/clk/imx/clk-fracn-gppll.c | 323 ++++++++++++++++++++++++++++++++++++++ drivers/clk/imx/clk.h | 21 +++ 3 files changed, 345 insertions(+) create mode 100644 drivers/clk/imx/clk-fracn-gppll.c diff --git a/drivers/clk/imx/Makefile b/drivers/clk/imx/Makefile index 36c0492..60c8a4b 100644 --- a/drivers/clk/imx/Makefile +++ b/drivers/clk/imx/Makefile @@ -5,6 +5,7 @@ mxc-clk-objs += clk-busy.o mxc-clk-objs += clk-composite-7ulp.o mxc-clk-objs += clk-composite-8m.o mxc-clk-objs += clk-composite-93.o +mxc-clk-objs += clk-fracn-gppll.o mxc-clk-objs += clk-cpu.o mxc-clk-objs += clk-divider-gate.o mxc-clk-objs += clk-fixup-div.o diff --git a/drivers/clk/imx/clk-fracn-gppll.c b/drivers/clk/imx/clk-fracn-gppll.c new file mode 100644 index 0000000..71c102d --- /dev/null +++ b/drivers/clk/imx/clk-fracn-gppll.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2021 NXP + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "clk.h" + +#define PLL_CTRL 0x0 +#define CLKMUX_BYPASS BIT(2) +#define CLKMUX_EN BIT(1) +#define POWERUP_MASK BIT(0) + +#define PLL_ANA_PRG 0x10 +#define PLL_SPREAD_SPECTRUM 0x30 + +#define PLL_NUMERATOR 0x40 +#define PLL_MFN_MASK GENMASK(31, 2) + +#define PLL_DENOMINATOR 0x50 +#define PLL_MFD_MASK GENMASK(29, 0) + +#define PLL_DIV 0x60 +#define PLL_MFI_MASK GENMASK(24, 16) +#define PLL_RDIV_MASK GENMASK(15, 13) +#define PLL_ODIV_MASK GENMASK(7, 0) + +#define PLL_DFS_CTRL(x) (0x70 + (x) * 0x10) + +#define PLL_STATUS 0xF0 +#define LOCK_STATUS BIT(0) + +#define DFS_STATUS 0xF4 + +#define LOCK_TIMEOUT_US 200 + +#define PLL_FRACN_GP(_rate, _mfi, _mfn, _mfd, _rdiv, _odiv) \ + { \ + .rate = (_rate), \ + .mfi = (_mfi), \ + .mfn = (_mfn), \ + .mfd = (_mfd), \ + .rdiv = (_rdiv), \ + .odiv = (_odiv), \ + } + +struct clk_fracn_gppll { + struct clk_hw hw; + void __iomem *base; + const struct imx_fracn_gppll_rate_table *rate_table; + int rate_count; +}; + +/* + * Fvco = Fref * (MFI + MFN / MFD) + * Fout = Fvco / (rdiv * odiv) + */ +static const struct imx_fracn_gppll_rate_table fracn_tbl[] = { + PLL_FRACN_GP(650000000U, 81, 0, 0, 0, 3), + PLL_FRACN_GP(594000000U, 198, 0, 0, 0, 8), + PLL_FRACN_GP(560000000U, 70, 0, 0, 0, 3), + PLL_FRACN_GP(400000000U, 50, 0, 0, 0, 3), + PLL_FRACN_GP(393216000U, 81, 92, 100, 0, 5) +}; + +struct imx_fracn_gppll_clk imx_fracn_gppll = { + .rate_table = fracn_tbl, + .rate_count = ARRAY_SIZE(fracn_tbl), +}; +EXPORT_SYMBOL_GPL(imx_fracn_gppll); + +static inline struct clk_fracn_gppll *to_clk_fracn_gppll(struct clk_hw *hw) +{ + return container_of(hw, struct clk_fracn_gppll, hw); +} + +static const struct imx_fracn_gppll_rate_table * +imx_get_pll_settings(struct clk_fracn_gppll *pll, unsigned long rate) +{ + const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table; + int i; + + for (i = 0; i < pll->rate_count; i++) + if (rate == rate_table[i].rate) + return &rate_table[i]; + + return NULL; +} + +static long clk_fracn_gppll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw); + const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table; + int i; + + /* Assuming rate_table is in descending order */ + for (i = 0; i < pll->rate_count; i++) + if (rate >= rate_table[i].rate) + return rate_table[i].rate; + + /* return minimum supported value */ + return rate_table[pll->rate_count - 1].rate; +} + +static unsigned long clk_fracn_gppll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw); + const struct imx_fracn_gppll_rate_table *rate_table = pll->rate_table; + u32 pll_numerator, pll_denominator, pll_div; + u32 mfi, mfn, mfd, rdiv, odiv; + u64 fvco = parent_rate; + long rate = 0; + int i; + + pll_numerator = readl_relaxed(pll->base + PLL_NUMERATOR); + mfn = FIELD_GET(PLL_MFN_MASK, pll_numerator); + + pll_denominator = readl_relaxed(pll->base + PLL_DENOMINATOR); + mfd = FIELD_GET(PLL_MFD_MASK, pll_denominator); + + pll_div = readl_relaxed(pll->base + PLL_DIV); + mfi = FIELD_GET(PLL_MFI_MASK, pll_div); + + rdiv = FIELD_GET(PLL_RDIV_MASK, pll_div); + rdiv = rdiv + 1; + odiv = FIELD_GET(PLL_ODIV_MASK, pll_div); + switch (odiv) { + case 0: + odiv = 2; + break; + case 1: + odiv = 3; + break; + default: + break; + } + + /* + * Sometimes, the recalculated rate has deviation due to + * the frac part. So find the accurate pll rate from the table + * first, if no match rate in the table, use the rate calculated + * from the equation below. + */ + for (i = 0; i < pll->rate_count; i++) { + if (rate_table[i].mfn == mfn && rate_table[i].mfi == mfi && + rate_table[i].mfd == mfd && rate_table[i].rdiv == rdiv && + rate_table[i].odiv == odiv) + rate = rate_table[i].rate; + } + + if (rate) + return (unsigned long)rate; + + /* Fvco = Fref * (MFI + MFN / MFD) */ + fvco = fvco * mfi * mfd + fvco * mfn; + do_div(fvco, mfd * rdiv * odiv); + + return (unsigned long)fvco; +} + +static int clk_fracn_gppll_wait_lock(struct clk_fracn_gppll *pll) +{ + u32 val; + + return readl_poll_timeout(pll->base + PLL_STATUS, val, + val & LOCK_STATUS, 0, LOCK_TIMEOUT_US); +} + +static int clk_fracn_gppll_set_rate(struct clk_hw *hw, unsigned long drate, + unsigned long prate) +{ + struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw); + const struct imx_fracn_gppll_rate_table *rate; + u32 tmp, pll_div, ana_mfn; + int ret; + + rate = imx_get_pll_settings(pll, drate); + + /* Disable output */ + tmp = readl_relaxed(pll->base + PLL_CTRL); + tmp &= ~CLKMUX_EN; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + /* Power Down */ + tmp &= ~POWERUP_MASK; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + /* Disable BYPASS */ + tmp &= ~CLKMUX_BYPASS; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + pll_div = FIELD_PREP(PLL_RDIV_MASK, rate->rdiv) | rate->odiv | + FIELD_PREP(PLL_MFI_MASK, rate->mfi); + writel_relaxed(pll_div, pll->base + PLL_DIV); + writel_relaxed(rate->mfd, pll->base + PLL_DENOMINATOR); + writel_relaxed(FIELD_PREP(PLL_MFN_MASK, rate->mfn), pll->base + PLL_NUMERATOR); + + /* Wait for 5us according to fracn mode pll doc */ + udelay(5); + + /* Enable Powerup */ + tmp |= POWERUP_MASK; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + /* Wait Lock */ + ret = clk_fracn_gppll_wait_lock(pll); + if (ret) + return ret; + + /* Enable output */ + tmp |= CLKMUX_EN; + writel_relaxed(tmp, pll->base + PLL_CTRL); + + ana_mfn = readl_relaxed(pll->base + PLL_STATUS); + ana_mfn = FIELD_GET(PLL_MFN_MASK, ana_mfn); + + WARN(ana_mfn != rate->mfn, "ana_mfn != rate->mfn\n"); + + return 0; +} + +static int clk_fracn_gppll_prepare(struct clk_hw *hw) +{ + struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw); + u32 val; + int ret; + + val = readl_relaxed(pll->base + PLL_CTRL); + if (val & POWERUP_MASK) + return 0; + + val |= CLKMUX_BYPASS; + writel_relaxed(val, pll->base + PLL_CTRL); + + val |= POWERUP_MASK; + writel_relaxed(val, pll->base + PLL_CTRL); + + val |= CLKMUX_EN; + writel_relaxed(val, pll->base + PLL_CTRL); + + ret = clk_fracn_gppll_wait_lock(pll); + if (ret) + return ret; + + val &= ~CLKMUX_BYPASS; + writel_relaxed(val, pll->base + PLL_CTRL); + + return 0; +} + +static int clk_fracn_gppll_is_prepared(struct clk_hw *hw) +{ + struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw); + u32 val; + + val = readl_relaxed(pll->base + PLL_CTRL); + + return (val & POWERUP_MASK) ? 1 : 0; +} + +static void clk_fracn_gppll_unprepare(struct clk_hw *hw) +{ + struct clk_fracn_gppll *pll = to_clk_fracn_gppll(hw); + u32 val; + + val = readl_relaxed(pll->base + PLL_CTRL); + val &= ~POWERUP_MASK; + writel_relaxed(val, pll->base + PLL_CTRL); +} + +static const struct clk_ops clk_fracn_gppll_ops = { + .prepare = clk_fracn_gppll_prepare, + .unprepare = clk_fracn_gppll_unprepare, + .is_prepared = clk_fracn_gppll_is_prepared, + .recalc_rate = clk_fracn_gppll_recalc_rate, + .round_rate = clk_fracn_gppll_round_rate, + .set_rate = clk_fracn_gppll_set_rate, +}; + +struct clk_hw *imx_clk_fracn_gppll(const char *name, const char *parent_name, void __iomem *base, + const struct imx_fracn_gppll_clk *pll_clk) +{ + struct clk_fracn_gppll *pll; + struct clk_hw *hw; + struct clk_init_data init; + int ret; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.flags = pll_clk->flags; + init.parent_names = &parent_name; + init.num_parents = 1; + init.ops = &clk_fracn_gppll_ops; + + pll->base = base; + pll->hw.init = &init; + pll->rate_table = pll_clk->rate_table; + pll->rate_count = pll_clk->rate_count; + + hw = &pll->hw; + + ret = clk_hw_register(NULL, hw); + if (ret) { + pr_err("%s: failed to register pll %s %d\n", __func__, name, ret); + kfree(pll); + return ERR_PTR(ret); + } + + return hw; +} +EXPORT_SYMBOL_GPL(imx_clk_fracn_gppll); diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h index 63eb7c5..a7cbbcd 100644 --- a/drivers/clk/imx/clk.h +++ b/drivers/clk/imx/clk.h @@ -72,6 +72,27 @@ extern struct imx_pll14xx_clk imx_1416x_pll; extern struct imx_pll14xx_clk imx_1443x_pll; extern struct imx_pll14xx_clk imx_1443x_dram_pll; +/* NOTE: Rate table should be kept sorted in descending order. */ +struct imx_fracn_gppll_rate_table { + unsigned int rate; + unsigned int mfi; + unsigned int mfn; + unsigned int mfd; + unsigned int rdiv; + unsigned int odiv; +}; + +struct imx_fracn_gppll_clk { + const struct imx_fracn_gppll_rate_table *rate_table; + int rate_count; + int flags; +}; + +struct clk_hw *imx_clk_fracn_gppll(const char *name, const char *parent_name, void __iomem *base, + const struct imx_fracn_gppll_clk *pll_clk); + +extern struct imx_fracn_gppll_clk imx_fracn_gppll; + #define imx_clk_cpu(name, parent_name, div, mux, pll, step) \ to_clk(imx_clk_hw_cpu(name, parent_name, div, mux, pll, step)) -- 2.7.4