diff options
author | Boris BREZILLON <b.brezillon@overkiz.com> | 2013-10-11 11:41:41 +0200 |
---|---|---|
committer | Nicolas Ferre <nicolas.ferre@atmel.com> | 2013-12-02 15:31:23 +0100 |
commit | 5fba62ea2648f89cbd7f0ed32069f03b179d05e9 (patch) | |
tree | 08615954736896eb8f9e07e26ebce6e330754177 | |
parent | e442d234405ad75e2d3d2baf15b364ee2c3573c9 (diff) |
clk: at91: add PMC system clocks
This patch adds new at91 system clock implementation using common clk
framework.
Some peripherals need to enable a "system" clock in order to work properly.
Each system clock is given an id based on the bit position in SCER/SCDR
registers.
Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
-rw-r--r-- | drivers/clk/at91/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/at91/clk-system.c | 135 | ||||
-rw-r--r-- | drivers/clk/at91/pmc.c | 5 | ||||
-rw-r--r-- | drivers/clk/at91/pmc.h | 3 |
4 files changed, 144 insertions, 0 deletions
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index e28fb2bbb19..c2b70683e4e 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -4,3 +4,4 @@ obj-y += pmc.o obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o +obj-y += clk-system.o diff --git a/drivers/clk/at91/clk-system.c b/drivers/clk/at91/clk-system.c new file mode 100644 index 00000000000..8f7c0434a09 --- /dev/null +++ b/drivers/clk/at91/clk-system.c @@ -0,0 +1,135 @@ +/* + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/at91_pmc.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/io.h> + +#include "pmc.h" + +#define SYSTEM_MAX_ID 31 + +#define SYSTEM_MAX_NAME_SZ 32 + +#define to_clk_system(hw) container_of(hw, struct clk_system, hw) +struct clk_system { + struct clk_hw hw; + struct at91_pmc *pmc; + u8 id; +}; + +static int clk_system_enable(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + struct at91_pmc *pmc = sys->pmc; + + pmc_write(pmc, AT91_PMC_SCER, 1 << sys->id); + return 0; +} + +static void clk_system_disable(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + struct at91_pmc *pmc = sys->pmc; + + pmc_write(pmc, AT91_PMC_SCDR, 1 << sys->id); +} + +static int clk_system_is_enabled(struct clk_hw *hw) +{ + struct clk_system *sys = to_clk_system(hw); + struct at91_pmc *pmc = sys->pmc; + + return !!(pmc_read(pmc, AT91_PMC_SCSR) & (1 << sys->id)); +} + +static const struct clk_ops system_ops = { + .enable = clk_system_enable, + .disable = clk_system_disable, + .is_enabled = clk_system_is_enabled, +}; + +static struct clk * __init +at91_clk_register_system(struct at91_pmc *pmc, const char *name, + const char *parent_name, u8 id) +{ + struct clk_system *sys; + struct clk *clk = NULL; + struct clk_init_data init; + + if (!parent_name || id > SYSTEM_MAX_ID) + return ERR_PTR(-EINVAL); + + sys = kzalloc(sizeof(*sys), GFP_KERNEL); + if (!sys) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &system_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + /* + * CLK_IGNORE_UNUSED is used to avoid ddrck switch off. + * TODO : we should implement a driver supporting at91 ddr controller + * (see drivers/memory) which would request and enable the ddrck clock. + * When this is done we will be able to remove CLK_IGNORE_UNUSED flag. + */ + init.flags = CLK_IGNORE_UNUSED; + + sys->id = id; + sys->hw.init = &init; + sys->pmc = pmc; + + clk = clk_register(NULL, &sys->hw); + if (IS_ERR(clk)) + kfree(sys); + + return clk; +} + +static void __init +of_at91_clk_sys_setup(struct device_node *np, struct at91_pmc *pmc) +{ + int num; + u32 id; + struct clk *clk; + const char *name; + struct device_node *sysclknp; + const char *parent_name; + + num = of_get_child_count(np); + if (num > (SYSTEM_MAX_ID + 1)) + return; + + for_each_child_of_node(np, sysclknp) { + if (of_property_read_u32(sysclknp, "reg", &id)) + continue; + + if (of_property_read_string(np, "clock-output-names", &name)) + name = sysclknp->name; + + parent_name = of_clk_get_parent_name(sysclknp, 0); + + clk = at91_clk_register_system(pmc, name, parent_name, id); + if (IS_ERR(clk)) + continue; + + of_clk_add_provider(sysclknp, of_clk_src_simple_get, clk); + } +} + +void __init of_at91rm9200_clk_sys_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_sys_setup(np, pmc); +} diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c index a311cf3d535..a97554f943e 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c @@ -264,6 +264,11 @@ static const struct of_device_id pmc_clk_ids[] __initdata = { .compatible = "atmel,at91sam9x5-clk-master", .data = of_at91sam9x5_clk_master_setup, }, + /* System clocks */ + { + .compatible = "atmel,at91rm9200-clk-system", + .data = of_at91rm9200_clk_sys_setup, + }, { /*sentinel*/ } }; diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index be5c964acca..9c8a397cb85 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -77,4 +77,7 @@ extern void __init of_at91rm9200_clk_master_setup(struct device_node *np, extern void __init of_at91sam9x5_clk_master_setup(struct device_node *np, struct at91_pmc *pmc); +extern void __init of_at91rm9200_clk_sys_setup(struct device_node *np, + struct at91_pmc *pmc); + #endif /* __PMC_H_ */ |