diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/imx/clk-sscg-pll.c | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-sscg-pll.c b/drivers/clk/imx/clk-sscg-pll.c new file mode 100644 index 000000000..9d6cdff05 --- /dev/null +++ b/drivers/clk/imx/clk-sscg-pll.c @@ -0,0 +1,541 @@ +// SPDX-License-Identifier: (GPL-2.0 OR MIT) +/* + * Copyright 2018 NXP. + * + * This driver supports the SCCG plls found in the imx8m SOCs + * + * Documentation for this SCCG pll can be found at: + * https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834 + */ + +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/slab.h> +#include <linux/bitfield.h> + +#include "clk.h" + +/* PLL CFGs */ +#define PLL_CFG0 0x0 +#define PLL_CFG1 0x4 +#define PLL_CFG2 0x8 + +#define PLL_DIVF1_MASK GENMASK(18, 13) +#define PLL_DIVF2_MASK GENMASK(12, 7) +#define PLL_DIVR1_MASK GENMASK(27, 25) +#define PLL_DIVR2_MASK GENMASK(24, 19) +#define PLL_DIVQ_MASK GENMASK(6, 1) +#define PLL_REF_MASK GENMASK(2, 0) + +#define PLL_LOCK_MASK BIT(31) +#define PLL_PD_MASK BIT(7) + +/* These are the specification limits for the SSCG PLL */ +#define PLL_REF_MIN_FREQ 25000000UL +#define PLL_REF_MAX_FREQ 235000000UL + +#define PLL_STAGE1_MIN_FREQ 1600000000UL +#define PLL_STAGE1_MAX_FREQ 2400000000UL + +#define PLL_STAGE1_REF_MIN_FREQ 25000000UL +#define PLL_STAGE1_REF_MAX_FREQ 54000000UL + +#define PLL_STAGE2_MIN_FREQ 1200000000UL +#define PLL_STAGE2_MAX_FREQ 2400000000UL + +#define PLL_STAGE2_REF_MIN_FREQ 54000000UL +#define PLL_STAGE2_REF_MAX_FREQ 75000000UL + +#define PLL_OUT_MIN_FREQ 20000000UL +#define PLL_OUT_MAX_FREQ 1200000000UL + +#define PLL_DIVR1_MAX 7 +#define PLL_DIVR2_MAX 63 +#define PLL_DIVF1_MAX 63 +#define PLL_DIVF2_MAX 63 +#define PLL_DIVQ_MAX 63 + +#define PLL_BYPASS_NONE 0x0 +#define PLL_BYPASS1 0x2 +#define PLL_BYPASS2 0x1 + +#define SSCG_PLL_BYPASS1_MASK BIT(5) +#define SSCG_PLL_BYPASS2_MASK BIT(4) +#define SSCG_PLL_BYPASS_MASK GENMASK(5, 4) + +#define PLL_SCCG_LOCK_TIMEOUT 70 + +struct clk_sscg_pll_setup { + int divr1, divf1; + int divr2, divf2; + int divq; + int bypass; + uint64_t vco1; + uint64_t vco2; + uint64_t fout; + uint64_t ref; + uint64_t ref_div1; + uint64_t ref_div2; + uint64_t fout_request; + int fout_error; +}; + +struct clk_sscg_pll { + struct clk_hw hw; + const struct clk_ops ops; + void __iomem *base; + struct clk_sscg_pll_setup setup; + u8 parent; + u8 bypass1; + u8 bypass2; +}; + +#define to_clk_sscg_pll(_hw) container_of(_hw, struct clk_sscg_pll, hw) + +static int clk_sscg_pll_wait_lock(struct clk_sscg_pll *pll) +{ + u32 val; + + val = readl_relaxed(pll->base + PLL_CFG0); + + /* don't wait for lock if all plls are bypassed */ + if (!(val & SSCG_PLL_BYPASS2_MASK)) + return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK, + 0, PLL_SCCG_LOCK_TIMEOUT); + + return 0; +} + +static int clk_sscg_pll2_check_match(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup) +{ + int new_diff = temp_setup->fout - temp_setup->fout_request; + int diff = temp_setup->fout_error; + + if (abs(diff) > abs(new_diff)) { + temp_setup->fout_error = new_diff; + memcpy(setup, temp_setup, sizeof(struct clk_sscg_pll_setup)); + + if (temp_setup->fout_request == temp_setup->fout) + return 0; + } + return -1; +} + +static int clk_sscg_divq_lookup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup) +{ + int ret = -EINVAL; + + for (temp_setup->divq = 0; temp_setup->divq <= PLL_DIVQ_MAX; + temp_setup->divq++) { + temp_setup->vco2 = temp_setup->vco1; + do_div(temp_setup->vco2, temp_setup->divr2 + 1); + temp_setup->vco2 *= 2; + temp_setup->vco2 *= temp_setup->divf2 + 1; + if (temp_setup->vco2 >= PLL_STAGE2_MIN_FREQ && + temp_setup->vco2 <= PLL_STAGE2_MAX_FREQ) { + temp_setup->fout = temp_setup->vco2; + do_div(temp_setup->fout, 2 * (temp_setup->divq + 1)); + + ret = clk_sscg_pll2_check_match(setup, temp_setup); + if (!ret) { + temp_setup->bypass = PLL_BYPASS1; + return ret; + } + } + } + + return ret; +} + +static int clk_sscg_divf2_lookup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup) +{ + int ret = -EINVAL; + + for (temp_setup->divf2 = 0; temp_setup->divf2 <= PLL_DIVF2_MAX; + temp_setup->divf2++) { + ret = clk_sscg_divq_lookup(setup, temp_setup); + if (!ret) + return ret; + } + + return ret; +} + +static int clk_sscg_divr2_lookup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup) +{ + int ret = -EINVAL; + + for (temp_setup->divr2 = 0; temp_setup->divr2 <= PLL_DIVR2_MAX; + temp_setup->divr2++) { + temp_setup->ref_div2 = temp_setup->vco1; + do_div(temp_setup->ref_div2, temp_setup->divr2 + 1); + if (temp_setup->ref_div2 >= PLL_STAGE2_REF_MIN_FREQ && + temp_setup->ref_div2 <= PLL_STAGE2_REF_MAX_FREQ) { + ret = clk_sscg_divf2_lookup(setup, temp_setup); + if (!ret) + return ret; + } + } + + return ret; +} + +static int clk_sscg_pll2_find_setup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup, + uint64_t ref) +{ + int ret; + + if (ref < PLL_STAGE1_MIN_FREQ || ref > PLL_STAGE1_MAX_FREQ) + return -EINVAL; + + temp_setup->vco1 = ref; + + ret = clk_sscg_divr2_lookup(setup, temp_setup); + return ret; +} + +static int clk_sscg_divf1_lookup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup) +{ + int ret = -EINVAL; + + for (temp_setup->divf1 = 0; temp_setup->divf1 <= PLL_DIVF1_MAX; + temp_setup->divf1++) { + uint64_t vco1 = temp_setup->ref; + + do_div(vco1, temp_setup->divr1 + 1); + vco1 *= 2; + vco1 *= temp_setup->divf1 + 1; + + ret = clk_sscg_pll2_find_setup(setup, temp_setup, vco1); + if (!ret) { + temp_setup->bypass = PLL_BYPASS_NONE; + return ret; + } + } + + return ret; +} + +static int clk_sscg_divr1_lookup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup) +{ + int ret = -EINVAL; + + for (temp_setup->divr1 = 0; temp_setup->divr1 <= PLL_DIVR1_MAX; + temp_setup->divr1++) { + temp_setup->ref_div1 = temp_setup->ref; + do_div(temp_setup->ref_div1, temp_setup->divr1 + 1); + if (temp_setup->ref_div1 >= PLL_STAGE1_REF_MIN_FREQ && + temp_setup->ref_div1 <= PLL_STAGE1_REF_MAX_FREQ) { + ret = clk_sscg_divf1_lookup(setup, temp_setup); + if (!ret) + return ret; + } + } + + return ret; +} + +static int clk_sscg_pll1_find_setup(struct clk_sscg_pll_setup *setup, + struct clk_sscg_pll_setup *temp_setup, + uint64_t ref) +{ + int ret; + + if (ref < PLL_REF_MIN_FREQ || ref > PLL_REF_MAX_FREQ) + return -EINVAL; + + temp_setup->ref = ref; + + ret = clk_sscg_divr1_lookup(setup, temp_setup); + + return ret; +} + +static int clk_sscg_pll_find_setup(struct clk_sscg_pll_setup *setup, + uint64_t prate, + uint64_t rate, int try_bypass) +{ + struct clk_sscg_pll_setup temp_setup; + int ret = -EINVAL; + + memset(&temp_setup, 0, sizeof(struct clk_sscg_pll_setup)); + memset(setup, 0, sizeof(struct clk_sscg_pll_setup)); + + temp_setup.fout_error = PLL_OUT_MAX_FREQ; + temp_setup.fout_request = rate; + + switch (try_bypass) { + case PLL_BYPASS2: + if (prate == rate) { + setup->bypass = PLL_BYPASS2; + setup->fout = rate; + ret = 0; + } + break; + case PLL_BYPASS1: + ret = clk_sscg_pll2_find_setup(setup, &temp_setup, prate); + break; + case PLL_BYPASS_NONE: + ret = clk_sscg_pll1_find_setup(setup, &temp_setup, prate); + break; + } + + return ret; +} + +static int clk_sscg_pll_is_prepared(struct clk_hw *hw) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + + u32 val = readl_relaxed(pll->base + PLL_CFG0); + + return (val & PLL_PD_MASK) ? 0 : 1; +} + +static int clk_sscg_pll_prepare(struct clk_hw *hw) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + u32 val; + + val = readl_relaxed(pll->base + PLL_CFG0); + val &= ~PLL_PD_MASK; + writel_relaxed(val, pll->base + PLL_CFG0); + + return clk_sscg_pll_wait_lock(pll); +} + +static void clk_sscg_pll_unprepare(struct clk_hw *hw) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + u32 val; + + val = readl_relaxed(pll->base + PLL_CFG0); + val |= PLL_PD_MASK; + writel_relaxed(val, pll->base + PLL_CFG0); +} + +static unsigned long clk_sscg_pll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + u32 val, divr1, divf1, divr2, divf2, divq; + u64 temp64; + + val = readl_relaxed(pll->base + PLL_CFG2); + divr1 = FIELD_GET(PLL_DIVR1_MASK, val); + divr2 = FIELD_GET(PLL_DIVR2_MASK, val); + divf1 = FIELD_GET(PLL_DIVF1_MASK, val); + divf2 = FIELD_GET(PLL_DIVF2_MASK, val); + divq = FIELD_GET(PLL_DIVQ_MASK, val); + + temp64 = parent_rate; + + val = readl(pll->base + PLL_CFG0); + if (val & SSCG_PLL_BYPASS2_MASK) { + temp64 = parent_rate; + } else if (val & SSCG_PLL_BYPASS1_MASK) { + temp64 *= divf2; + do_div(temp64, (divr2 + 1) * (divq + 1)); + } else { + temp64 *= 2; + temp64 *= (divf1 + 1) * (divf2 + 1); + do_div(temp64, (divr1 + 1) * (divr2 + 1) * (divq + 1)); + } + + return temp64; +} + +static int clk_sscg_pll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + struct clk_sscg_pll_setup *setup = &pll->setup; + u32 val; + + /* set bypass here too since the parent might be the same */ + val = readl(pll->base + PLL_CFG0); + val &= ~SSCG_PLL_BYPASS_MASK; + val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, setup->bypass); + writel(val, pll->base + PLL_CFG0); + + val = readl_relaxed(pll->base + PLL_CFG2); + val &= ~(PLL_DIVF1_MASK | PLL_DIVF2_MASK); + val &= ~(PLL_DIVR1_MASK | PLL_DIVR2_MASK | PLL_DIVQ_MASK); + val |= FIELD_PREP(PLL_DIVF1_MASK, setup->divf1); + val |= FIELD_PREP(PLL_DIVF2_MASK, setup->divf2); + val |= FIELD_PREP(PLL_DIVR1_MASK, setup->divr1); + val |= FIELD_PREP(PLL_DIVR2_MASK, setup->divr2); + val |= FIELD_PREP(PLL_DIVQ_MASK, setup->divq); + writel_relaxed(val, pll->base + PLL_CFG2); + + return clk_sscg_pll_wait_lock(pll); +} + +static u8 clk_sscg_pll_get_parent(struct clk_hw *hw) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + u32 val; + u8 ret = pll->parent; + + val = readl(pll->base + PLL_CFG0); + if (val & SSCG_PLL_BYPASS2_MASK) + ret = pll->bypass2; + else if (val & SSCG_PLL_BYPASS1_MASK) + ret = pll->bypass1; + return ret; +} + +static int clk_sscg_pll_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + u32 val; + + val = readl(pll->base + PLL_CFG0); + val &= ~SSCG_PLL_BYPASS_MASK; + val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, pll->setup.bypass); + writel(val, pll->base + PLL_CFG0); + + return clk_sscg_pll_wait_lock(pll); +} + +static int __clk_sscg_pll_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req, + uint64_t min, + uint64_t max, + uint64_t rate, + int bypass) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + struct clk_sscg_pll_setup *setup = &pll->setup; + struct clk_hw *parent_hw = NULL; + int bypass_parent_index; + int ret; + + req->max_rate = max; + req->min_rate = min; + + switch (bypass) { + case PLL_BYPASS2: + bypass_parent_index = pll->bypass2; + break; + case PLL_BYPASS1: + bypass_parent_index = pll->bypass1; + break; + default: + bypass_parent_index = pll->parent; + break; + } + + parent_hw = clk_hw_get_parent_by_index(hw, bypass_parent_index); + ret = __clk_determine_rate(parent_hw, req); + if (!ret) { + ret = clk_sscg_pll_find_setup(setup, req->rate, + rate, bypass); + } + + req->best_parent_hw = parent_hw; + req->best_parent_rate = req->rate; + req->rate = setup->fout; + + return ret; +} + +static int clk_sscg_pll_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct clk_sscg_pll *pll = to_clk_sscg_pll(hw); + struct clk_sscg_pll_setup *setup = &pll->setup; + uint64_t rate = req->rate; + uint64_t min = req->min_rate; + uint64_t max = req->max_rate; + int ret; + + if (rate < PLL_OUT_MIN_FREQ || rate > PLL_OUT_MAX_FREQ) + return -EINVAL; + + ret = __clk_sscg_pll_determine_rate(hw, req, req->rate, req->rate, + rate, PLL_BYPASS2); + if (!ret) + return ret; + + ret = __clk_sscg_pll_determine_rate(hw, req, PLL_STAGE1_REF_MIN_FREQ, + PLL_STAGE1_REF_MAX_FREQ, rate, + PLL_BYPASS1); + if (!ret) + return ret; + + ret = __clk_sscg_pll_determine_rate(hw, req, PLL_REF_MIN_FREQ, + PLL_REF_MAX_FREQ, rate, + PLL_BYPASS_NONE); + if (!ret) + return ret; + + if (setup->fout >= min && setup->fout <= max) + ret = 0; + + return ret; +} + +static const struct clk_ops clk_sscg_pll_ops = { + .prepare = clk_sscg_pll_prepare, + .unprepare = clk_sscg_pll_unprepare, + .is_prepared = clk_sscg_pll_is_prepared, + .recalc_rate = clk_sscg_pll_recalc_rate, + .set_rate = clk_sscg_pll_set_rate, + .set_parent = clk_sscg_pll_set_parent, + .get_parent = clk_sscg_pll_get_parent, + .determine_rate = clk_sscg_pll_determine_rate, +}; + +struct clk_hw *imx_clk_hw_sscg_pll(const char *name, + const char * const *parent_names, + u8 num_parents, + u8 parent, u8 bypass1, u8 bypass2, + void __iomem *base, + unsigned long flags) +{ + struct clk_sscg_pll *pll; + struct clk_init_data init; + struct clk_hw *hw; + int ret; + + pll = kzalloc(sizeof(*pll), GFP_KERNEL); + if (!pll) + return ERR_PTR(-ENOMEM); + + pll->parent = parent; + pll->bypass1 = bypass1; + pll->bypass2 = bypass2; + + pll->base = base; + init.name = name; + init.ops = &clk_sscg_pll_ops; + + init.flags = flags; + init.parent_names = parent_names; + init.num_parents = num_parents; + + pll->base = base; + pll->hw.init = &init; + + hw = &pll->hw; + + ret = clk_hw_register(NULL, hw); + if (ret) { + kfree(pll); + return ERR_PTR(ret); + } + + return hw; +} +EXPORT_SYMBOL_GPL(imx_clk_hw_sscg_pll); |