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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * Programmable clock support for AT91 architectures.
- *
- * Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
- *
- * Author: Claudiu Beznea <claudiu.beznea@microchip.com>
- *
- * Based on drivers/clk/at91/clk-programmable.c from Linux.
- */
- #include <common.h>
- #include <clk-uclass.h>
- #include <dm.h>
- #include <linux/clk-provider.h>
- #include <linux/clk/at91_pmc.h>
- #include "pmc.h"
- #define UBOOT_DM_CLK_AT91_PROG "at91-prog-clk"
- #define PROG_ID_MAX 7
- #define PROG_STATUS_MASK(id) (1 << ((id) + 8))
- #define PROG_PRES(_l, _p) (((_p) >> (_l)->pres_shift) & (_l)->pres_mask)
- #define PROG_MAX_RM9200_CSS 3
- struct clk_programmable {
- void __iomem *base;
- const u32 *clk_mux_table;
- const u32 *mux_table;
- const struct clk_programmable_layout *layout;
- u32 num_parents;
- struct clk clk;
- u8 id;
- };
- #define to_clk_programmable(_c) container_of(_c, struct clk_programmable, clk)
- static ulong clk_programmable_get_rate(struct clk *clk)
- {
- struct clk_programmable *prog = to_clk_programmable(clk);
- const struct clk_programmable_layout *layout = prog->layout;
- ulong rate, parent_rate = clk_get_parent_rate(clk);
- unsigned int pckr;
- pmc_read(prog->base, AT91_PMC_PCKR(prog->id), &pckr);
- if (layout->is_pres_direct)
- rate = parent_rate / (PROG_PRES(layout, pckr) + 1);
- else
- rate = parent_rate >> PROG_PRES(layout, pckr);
- return rate;
- }
- static int clk_programmable_set_parent(struct clk *clk, struct clk *parent)
- {
- struct clk_programmable *prog = to_clk_programmable(clk);
- const struct clk_programmable_layout *layout = prog->layout;
- unsigned int mask = layout->css_mask;
- int index;
- index = at91_clk_mux_val_to_index(prog->clk_mux_table,
- prog->num_parents, parent->id);
- if (index < 0)
- return index;
- index = at91_clk_mux_index_to_val(prog->mux_table, prog->num_parents,
- index);
- if (index < 0)
- return index;
- if (layout->have_slck_mck)
- mask |= AT91_PMC_CSSMCK_MCK;
- if (index > layout->css_mask) {
- if (index > PROG_MAX_RM9200_CSS && !layout->have_slck_mck)
- return -EINVAL;
- index |= AT91_PMC_CSSMCK_MCK;
- }
- pmc_update_bits(prog->base, AT91_PMC_PCKR(prog->id), mask, index);
- return 0;
- }
- static ulong clk_programmable_set_rate(struct clk *clk, ulong rate)
- {
- struct clk_programmable *prog = to_clk_programmable(clk);
- const struct clk_programmable_layout *layout = prog->layout;
- ulong parent_rate = clk_get_parent_rate(clk);
- ulong div = parent_rate / rate;
- int shift = 0;
- if (!parent_rate || !div)
- return -EINVAL;
- if (layout->is_pres_direct) {
- shift = div - 1;
- if (shift > layout->pres_mask)
- return -EINVAL;
- } else {
- shift = fls(div) - 1;
- if (div != (1 << shift))
- return -EINVAL;
- if (shift >= layout->pres_mask)
- return -EINVAL;
- }
- pmc_update_bits(prog->base, AT91_PMC_PCKR(prog->id),
- layout->pres_mask << layout->pres_shift,
- shift << layout->pres_shift);
- if (layout->is_pres_direct)
- return (parent_rate / shift + 1);
- return parent_rate >> shift;
- }
- static const struct clk_ops programmable_ops = {
- .get_rate = clk_programmable_get_rate,
- .set_parent = clk_programmable_set_parent,
- .set_rate = clk_programmable_set_rate,
- };
- struct clk *at91_clk_register_programmable(void __iomem *base, const char *name,
- const char *const *parent_names, u8 num_parents, u8 id,
- const struct clk_programmable_layout *layout,
- const u32 *clk_mux_table, const u32 *mux_table)
- {
- struct clk_programmable *prog;
- struct clk *clk;
- u32 val, tmp;
- int ret;
- if (!base || !name || !parent_names || !num_parents ||
- !layout || !clk_mux_table || !mux_table || id > PROG_ID_MAX)
- return ERR_PTR(-EINVAL);
- prog = kzalloc(sizeof(*prog), GFP_KERNEL);
- if (!prog)
- return ERR_PTR(-ENOMEM);
- prog->id = id;
- prog->layout = layout;
- prog->base = base;
- prog->clk_mux_table = clk_mux_table;
- prog->mux_table = mux_table;
- prog->num_parents = num_parents;
- pmc_read(prog->base, AT91_PMC_PCKR(prog->id), &tmp);
- val = tmp & prog->layout->css_mask;
- if (layout->have_slck_mck && (tmp & AT91_PMC_CSSMCK_MCK) && !val)
- ret = PROG_MAX_RM9200_CSS + 1;
- else
- ret = at91_clk_mux_val_to_index(prog->mux_table,
- prog->num_parents, val);
- if (ret < 0) {
- kfree(prog);
- return ERR_PTR(ret);
- }
- clk = &prog->clk;
- clk->flags = CLK_GET_RATE_NOCACHE;
- ret = clk_register(clk, UBOOT_DM_CLK_AT91_PROG, name,
- parent_names[ret]);
- if (ret) {
- kfree(prog);
- clk = ERR_PTR(ret);
- }
- return clk;
- }
- U_BOOT_DRIVER(at91_prog_clk) = {
- .name = UBOOT_DM_CLK_AT91_PROG,
- .id = UCLASS_CLK,
- .ops = &programmable_ops,
- .flags = DM_FLAG_PRE_RELOC,
- };
- const struct clk_programmable_layout at91rm9200_programmable_layout = {
- .pres_mask = 0x7,
- .pres_shift = 2,
- .css_mask = 0x3,
- .have_slck_mck = 0,
- .is_pres_direct = 0,
- };
- const struct clk_programmable_layout at91sam9g45_programmable_layout = {
- .pres_mask = 0x7,
- .pres_shift = 2,
- .css_mask = 0x3,
- .have_slck_mck = 1,
- .is_pres_direct = 0,
- };
- const struct clk_programmable_layout at91sam9x5_programmable_layout = {
- .pres_mask = 0x7,
- .pres_shift = 4,
- .css_mask = 0x7,
- .have_slck_mck = 0,
- .is_pres_direct = 0,
- };
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