diff options
Diffstat (limited to 'drivers/clk/at91/clk-programmable.c')
| -rw-r--r-- | drivers/clk/at91/clk-programmable.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c new file mode 100644 index 0000000000..868de4b177 --- /dev/null +++ b/drivers/clk/at91/clk-programmable.c @@ -0,0 +1,208 @@ +// 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, +}; |