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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/at91/clk-peripheral.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c new file mode 100644 index 000000000..5104d4025 --- /dev/null +++ b/drivers/clk/at91/clk-peripheral.c @@ -0,0 +1,495 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + */ + +#include <linux/bitops.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_SPINLOCK(pmc_pcr_lock); + +#define PERIPHERAL_ID_MIN 2 +#define PERIPHERAL_ID_MAX 31 +#define PERIPHERAL_MASK(id) (1 << ((id) & PERIPHERAL_ID_MAX)) + +#define PERIPHERAL_MAX_SHIFT 3 + +struct clk_peripheral { + struct clk_hw hw; + struct regmap *regmap; + u32 id; +}; + +#define to_clk_peripheral(hw) container_of(hw, struct clk_peripheral, hw) + +struct clk_sam9x5_peripheral { + struct clk_hw hw; + struct regmap *regmap; + struct clk_range range; + spinlock_t *lock; + u32 id; + u32 div; + const struct clk_pcr_layout *layout; + struct at91_clk_pms pms; + bool auto_div; + int chg_pid; +}; + +#define to_clk_sam9x5_peripheral(hw) \ + container_of(hw, struct clk_sam9x5_peripheral, hw) + +static int clk_peripheral_enable(struct clk_hw *hw) +{ + struct clk_peripheral *periph = to_clk_peripheral(hw); + int offset = AT91_PMC_PCER; + u32 id = periph->id; + + if (id < PERIPHERAL_ID_MIN) + return 0; + if (id > PERIPHERAL_ID_MAX) + offset = AT91_PMC_PCER1; + regmap_write(periph->regmap, offset, PERIPHERAL_MASK(id)); + + return 0; +} + +static void clk_peripheral_disable(struct clk_hw *hw) +{ + struct clk_peripheral *periph = to_clk_peripheral(hw); + int offset = AT91_PMC_PCDR; + u32 id = periph->id; + + if (id < PERIPHERAL_ID_MIN) + return; + if (id > PERIPHERAL_ID_MAX) + offset = AT91_PMC_PCDR1; + regmap_write(periph->regmap, offset, PERIPHERAL_MASK(id)); +} + +static int clk_peripheral_is_enabled(struct clk_hw *hw) +{ + struct clk_peripheral *periph = to_clk_peripheral(hw); + int offset = AT91_PMC_PCSR; + unsigned int status; + u32 id = periph->id; + + if (id < PERIPHERAL_ID_MIN) + return 1; + if (id > PERIPHERAL_ID_MAX) + offset = AT91_PMC_PCSR1; + regmap_read(periph->regmap, offset, &status); + + return status & PERIPHERAL_MASK(id) ? 1 : 0; +} + +static const struct clk_ops peripheral_ops = { + .enable = clk_peripheral_enable, + .disable = clk_peripheral_disable, + .is_enabled = clk_peripheral_is_enabled, +}; + +struct clk_hw * __init +at91_clk_register_peripheral(struct regmap *regmap, const char *name, + const char *parent_name, u32 id) +{ + struct clk_peripheral *periph; + struct clk_init_data init; + struct clk_hw *hw; + int ret; + + if (!name || !parent_name || id > PERIPHERAL_ID_MAX) + return ERR_PTR(-EINVAL); + + periph = kzalloc(sizeof(*periph), GFP_KERNEL); + if (!periph) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &peripheral_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = 0; + + periph->id = id; + periph->hw.init = &init; + periph->regmap = regmap; + + hw = &periph->hw; + ret = clk_hw_register(NULL, &periph->hw); + if (ret) { + kfree(periph); + hw = ERR_PTR(ret); + } + + return hw; +} + +static void clk_sam9x5_peripheral_autodiv(struct clk_sam9x5_peripheral *periph) +{ + struct clk_hw *parent; + unsigned long parent_rate; + int shift = 0; + + if (!periph->auto_div) + return; + + if (periph->range.max) { + parent = clk_hw_get_parent_by_index(&periph->hw, 0); + parent_rate = clk_hw_get_rate(parent); + if (!parent_rate) + return; + + for (; shift < PERIPHERAL_MAX_SHIFT; shift++) { + if (parent_rate >> shift <= periph->range.max) + break; + } + } + + periph->auto_div = false; + periph->div = shift; +} + +static int clk_sam9x5_peripheral_set(struct clk_sam9x5_peripheral *periph, + unsigned int status) +{ + unsigned long flags; + unsigned int enable = status ? AT91_PMC_PCR_EN : 0; + + if (periph->id < PERIPHERAL_ID_MIN) + return 0; + + spin_lock_irqsave(periph->lock, flags); + regmap_write(periph->regmap, periph->layout->offset, + (periph->id & periph->layout->pid_mask)); + regmap_update_bits(periph->regmap, periph->layout->offset, + periph->layout->div_mask | periph->layout->cmd | + enable, + field_prep(periph->layout->div_mask, periph->div) | + periph->layout->cmd | enable); + spin_unlock_irqrestore(periph->lock, flags); + + return 0; +} + +static int clk_sam9x5_peripheral_enable(struct clk_hw *hw) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + + return clk_sam9x5_peripheral_set(periph, 1); +} + +static void clk_sam9x5_peripheral_disable(struct clk_hw *hw) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + unsigned long flags; + + if (periph->id < PERIPHERAL_ID_MIN) + return; + + spin_lock_irqsave(periph->lock, flags); + regmap_write(periph->regmap, periph->layout->offset, + (periph->id & periph->layout->pid_mask)); + regmap_update_bits(periph->regmap, periph->layout->offset, + AT91_PMC_PCR_EN | periph->layout->cmd, + periph->layout->cmd); + spin_unlock_irqrestore(periph->lock, flags); +} + +static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + unsigned long flags; + unsigned int status; + + if (periph->id < PERIPHERAL_ID_MIN) + return 1; + + spin_lock_irqsave(periph->lock, flags); + regmap_write(periph->regmap, periph->layout->offset, + (periph->id & periph->layout->pid_mask)); + regmap_read(periph->regmap, periph->layout->offset, &status); + spin_unlock_irqrestore(periph->lock, flags); + + return !!(status & AT91_PMC_PCR_EN); +} + +static unsigned long +clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + unsigned long flags; + unsigned int status; + + if (periph->id < PERIPHERAL_ID_MIN) + return parent_rate; + + spin_lock_irqsave(periph->lock, flags); + regmap_write(periph->regmap, periph->layout->offset, + (periph->id & periph->layout->pid_mask)); + regmap_read(periph->regmap, periph->layout->offset, &status); + spin_unlock_irqrestore(periph->lock, flags); + + if (status & AT91_PMC_PCR_EN) { + periph->div = field_get(periph->layout->div_mask, status); + periph->auto_div = false; + } else { + clk_sam9x5_peripheral_autodiv(periph); + } + + return parent_rate >> periph->div; +} + +static void clk_sam9x5_peripheral_best_diff(struct clk_rate_request *req, + struct clk_hw *parent, + unsigned long parent_rate, + u32 shift, long *best_diff, + long *best_rate) +{ + unsigned long tmp_rate = parent_rate >> shift; + unsigned long tmp_diff = abs(req->rate - tmp_rate); + + if (*best_diff < 0 || *best_diff >= tmp_diff) { + *best_rate = tmp_rate; + *best_diff = tmp_diff; + req->best_parent_rate = parent_rate; + req->best_parent_hw = parent; + } +} + +static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + struct clk_hw *parent = clk_hw_get_parent(hw); + unsigned long parent_rate = clk_hw_get_rate(parent); + unsigned long tmp_rate; + long best_rate = LONG_MIN; + long best_diff = LONG_MIN; + u32 shift; + + if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) + return parent_rate; + + /* Fist step: check the available dividers. */ + for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) { + tmp_rate = parent_rate >> shift; + + if (periph->range.max && tmp_rate > periph->range.max) + continue; + + clk_sam9x5_peripheral_best_diff(req, parent, parent_rate, + shift, &best_diff, &best_rate); + + if (!best_diff || best_rate <= req->rate) + break; + } + + if (periph->chg_pid < 0) + goto end; + + /* Step two: try to request rate from parent. */ + parent = clk_hw_get_parent_by_index(hw, periph->chg_pid); + if (!parent) + goto end; + + for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) { + struct clk_rate_request req_parent; + + clk_hw_forward_rate_request(hw, req, parent, &req_parent, req->rate << shift); + if (__clk_determine_rate(parent, &req_parent)) + continue; + + clk_sam9x5_peripheral_best_diff(req, parent, req_parent.rate, + shift, &best_diff, &best_rate); + + if (!best_diff) + break; + } +end: + if (best_rate < 0 || + (periph->range.max && best_rate > periph->range.max)) + return -EINVAL; + + pr_debug("PCK: %s, best_rate = %ld, parent clk: %s @ %ld\n", + __func__, best_rate, + __clk_get_name((req->best_parent_hw)->clk), + req->best_parent_rate); + + req->rate = best_rate; + + return 0; +} + +static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate) +{ + int shift = 0; + unsigned long best_rate; + unsigned long best_diff; + unsigned long cur_rate = *parent_rate; + unsigned long cur_diff; + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + + if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) + return *parent_rate; + + if (periph->range.max) { + for (; shift <= PERIPHERAL_MAX_SHIFT; shift++) { + cur_rate = *parent_rate >> shift; + if (cur_rate <= periph->range.max) + break; + } + } + + if (rate >= cur_rate) + return cur_rate; + + best_diff = cur_rate - rate; + best_rate = cur_rate; + for (; shift <= PERIPHERAL_MAX_SHIFT; shift++) { + cur_rate = *parent_rate >> shift; + if (cur_rate < rate) + cur_diff = rate - cur_rate; + else + cur_diff = cur_rate - rate; + + if (cur_diff < best_diff) { + best_diff = cur_diff; + best_rate = cur_rate; + } + + if (!best_diff || cur_rate < rate) + break; + } + + return best_rate; +} + +static int clk_sam9x5_peripheral_set_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long parent_rate) +{ + int shift; + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) { + if (parent_rate == rate) + return 0; + else + return -EINVAL; + } + + if (periph->range.max && rate > periph->range.max) + return -EINVAL; + + for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) { + if (parent_rate >> shift == rate) { + periph->auto_div = false; + periph->div = shift; + return 0; + } + } + + return -EINVAL; +} + +static int clk_sam9x5_peripheral_save_context(struct clk_hw *hw) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + + periph->pms.status = clk_sam9x5_peripheral_is_enabled(hw); + + return 0; +} + +static void clk_sam9x5_peripheral_restore_context(struct clk_hw *hw) +{ + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + + if (periph->pms.status) + clk_sam9x5_peripheral_set(periph, periph->pms.status); +} + +static const struct clk_ops sam9x5_peripheral_ops = { + .enable = clk_sam9x5_peripheral_enable, + .disable = clk_sam9x5_peripheral_disable, + .is_enabled = clk_sam9x5_peripheral_is_enabled, + .recalc_rate = clk_sam9x5_peripheral_recalc_rate, + .round_rate = clk_sam9x5_peripheral_round_rate, + .set_rate = clk_sam9x5_peripheral_set_rate, + .save_context = clk_sam9x5_peripheral_save_context, + .restore_context = clk_sam9x5_peripheral_restore_context, +}; + +static const struct clk_ops sam9x5_peripheral_chg_ops = { + .enable = clk_sam9x5_peripheral_enable, + .disable = clk_sam9x5_peripheral_disable, + .is_enabled = clk_sam9x5_peripheral_is_enabled, + .recalc_rate = clk_sam9x5_peripheral_recalc_rate, + .determine_rate = clk_sam9x5_peripheral_determine_rate, + .set_rate = clk_sam9x5_peripheral_set_rate, + .save_context = clk_sam9x5_peripheral_save_context, + .restore_context = clk_sam9x5_peripheral_restore_context, +}; + +struct clk_hw * __init +at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock, + const struct clk_pcr_layout *layout, + const char *name, const char *parent_name, + u32 id, const struct clk_range *range, + int chg_pid) +{ + struct clk_sam9x5_peripheral *periph; + struct clk_init_data init; + struct clk_hw *hw; + int ret; + + if (!name || !parent_name) + return ERR_PTR(-EINVAL); + + periph = kzalloc(sizeof(*periph), GFP_KERNEL); + if (!periph) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.parent_names = &parent_name; + init.num_parents = 1; + if (chg_pid < 0) { + init.flags = 0; + init.ops = &sam9x5_peripheral_ops; + } else { + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE | + CLK_SET_RATE_PARENT; + init.ops = &sam9x5_peripheral_chg_ops; + } + + periph->id = id; + periph->hw.init = &init; + periph->div = 0; + periph->regmap = regmap; + periph->lock = lock; + if (layout->div_mask) + periph->auto_div = true; + periph->layout = layout; + periph->range = *range; + periph->chg_pid = chg_pid; + + hw = &periph->hw; + ret = clk_hw_register(NULL, &periph->hw); + if (ret) { + kfree(periph); + hw = ERR_PTR(ret); + } else { + clk_sam9x5_peripheral_autodiv(periph); + } + + return hw; +} |