On 08/08/2013 08:12, Boris BREZILLON :
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@xxxxxxxxxxx> --- drivers/clk/at91/Makefile | 1 + drivers/clk/at91/clk-system.c | 191 +++++++++++++++++++++++++++++++++++++++++ drivers/clk/at91/pmc.c | 5 ++ drivers/clk/at91/pmc.h | 3 + 4 files changed, 200 insertions(+) create mode 100644 drivers/clk/at91/clk-system.c diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index e28fb2b..c2b7068 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 0000000..11a3eb8 --- /dev/null +++ b/drivers/clk/at91/clk-system.c @@ -0,0 +1,191 @@ +/* + * drivers/clk/at91/clk-system.c + * + * Copyright (C) 2013 Boris BREZILLON <b.brezillon@xxxxxxxxxxx> + * + * 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 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, u8 id) +{ + struct clk_system *sys; + struct clk *clk = NULL; + struct clk_init_data init; + + id &= 31;
defined constant. Or event return an error instead of masking it (same for pll ids if I remember well).
+ + sys = kzalloc(sizeof(*sys), GFP_KERNEL); + if (!sys) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &system_ops; + init.parent_names = NULL; + init.num_parents = 0; + /* + * 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_IS_ROOT | CLK_IGNORE_UNUSED;
Is it a root clock? Usually clock parent for USB is UTMI or PLLB, LCD is usually the MCK. But I do not know how it interfere with your clock tree...
+ + sys->id = id; + sys->hw.init = &init; + sys->pmc = pmc; + + clk = clk_register(NULL, &sys->hw); + + if (IS_ERR(clk)) + kfree(sys); + + return clk; +} + +struct clk_system_data { + struct clk **clks; + u8 *ids; + unsigned int clk_num; +}; + +static struct clk * __init +of_clk_src_system_get(struct of_phandle_args *clkspec, void *data) +{ + struct clk_system_data *clk_data = data; + unsigned int id = clkspec->args[0]; + int i; + + if (id >= SYSTEM_MAX) + goto err; + + for (i = 0; i < clk_data->clk_num; i++) { + if (clk_data->ids[i] == id) + return clk_data->clks[i]; + } + +err: + pr_err("%s: invalid clock id %d\n", __func__, id); + return ERR_PTR(-EINVAL); +} + +static void __init +of_at91_clk_sys_setup(struct device_node *np, struct at91_pmc *pmc) +{ + int i; + int num; + u32 id; + struct clk *clk; + u8 *ids; + struct clk **clks; + struct clk_system_data *clktab; + const char *name; + struct device_node *sysclknp; + + num = of_get_child_count(np); + if (num > SYSTEM_MAX) + return; + + clktab = kzalloc(sizeof(*clktab), GFP_KERNEL); + if (!clktab) + return; + + ids = kzalloc(num * sizeof(*ids), GFP_KERNEL); + if (!ids) + goto out_free_clktab; + + clks = kzalloc(num * sizeof(*clks), GFP_KERNEL); + if (!clks) + goto out_free_ids; + + i = 0; + for_each_child_of_node(np, sysclknp) { + name = sysclknp->name; + + if (of_property_read_u32(sysclknp, "atmel,clk-id", &id)) + goto out_free_clks; + if (id >= SYSTEM_MAX) + goto out_free_clks; + + clk = at91_clk_register_system(pmc, name, id); + if (IS_ERR(clk)) + goto out_free_clks; + + clks[i] = clk; + ids[i] = id; + + i++; + } + + clktab->clk_num = num; + clktab->clks = clks; + clktab->ids = ids; + of_clk_add_provider(np, of_clk_src_system_get, clktab); + return; + +out_free_clks: + kfree(clks); +out_free_ids: + kfree(ids); +out_free_clktab: + kfree(clktab); +} + +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 5258f1d..c674ef2 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c @@ -251,6 +251,11 @@ 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 2e1dcb8..f88ef41 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -74,4 +74,7 @@ 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_ */
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