diff options
Diffstat (limited to 'roms/u-boot/drivers/clk/at91/clk-system.c')
-rw-r--r-- | roms/u-boot/drivers/clk/at91/clk-system.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/clk/at91/clk-system.c b/roms/u-boot/drivers/clk/at91/clk-system.c new file mode 100644 index 000000000..82f79e74a --- /dev/null +++ b/roms/u-boot/drivers/clk/at91/clk-system.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * System clock support for AT91 architectures. + * + * Copyright (C) Microchip Technology Inc. and its subsidiaries + * + * Author: Claudiu Beznea <claudiu.beznea@microchip.com> + * + * Based on drivers/clk/at91/clk-system.c from Linux. + */ +#include <asm/processor.h> +#include <common.h> +#include <clk-uclass.h> +#include <dm.h> +#include <linux/io.h> +#include <linux/clk-provider.h> +#include <linux/clk/at91_pmc.h> + +#include "pmc.h" + +#define UBOOT_DM_CLK_AT91_SYSTEM "at91-system-clk" + +#define SYSTEM_MAX_ID 31 + +struct clk_system { + void __iomem *base; + struct clk clk; + u8 id; +}; + +#define to_clk_system(_c) container_of(_c, struct clk_system, clk) + +static inline int is_pck(int id) +{ + return (id >= 8) && (id <= 15); +} + +static inline bool clk_system_ready(void __iomem *base, int id) +{ + unsigned int status; + + pmc_read(base, AT91_PMC_SR, &status); + + return !!(status & (1 << id)); +} + +static int clk_system_enable(struct clk *clk) +{ + struct clk_system *sys = to_clk_system(clk); + + pmc_write(sys->base, AT91_PMC_SCER, 1 << sys->id); + + if (!is_pck(sys->id)) + return 0; + + while (!clk_system_ready(sys->base, sys->id)) { + debug("waiting for pck%u\n", sys->id); + cpu_relax(); + } + + return 0; +} + +static int clk_system_disable(struct clk *clk) +{ + struct clk_system *sys = to_clk_system(clk); + + pmc_write(sys->base, AT91_PMC_SCDR, 1 << sys->id); + + return 0; +} + +static const struct clk_ops system_ops = { + .enable = clk_system_enable, + .disable = clk_system_disable, + .get_rate = clk_generic_get_rate, +}; + +struct clk *at91_clk_register_system(void __iomem *base, const char *name, + const char *parent_name, u8 id) +{ + struct clk_system *sys; + struct clk *clk; + int ret; + + if (!base || !name || !parent_name || id > SYSTEM_MAX_ID) + return ERR_PTR(-EINVAL); + + sys = kzalloc(sizeof(*sys), GFP_KERNEL); + if (!sys) + return ERR_PTR(-ENOMEM); + + sys->id = id; + sys->base = base; + + clk = &sys->clk; + clk->flags = CLK_GET_RATE_NOCACHE; + ret = clk_register(clk, UBOOT_DM_CLK_AT91_SYSTEM, name, parent_name); + if (ret) { + kfree(sys); + clk = ERR_PTR(ret); + } + + return clk; +} + +U_BOOT_DRIVER(at91_system_clk) = { + .name = UBOOT_DM_CLK_AT91_SYSTEM, + .id = UCLASS_CLK, + .ops = &system_ops, + .flags = DM_FLAG_PRE_RELOC, +}; |