Messages in this thread | | | Date | Thu, 17 Oct 2013 17:59:50 +0200 | From | Nicolas Ferre <> | Subject | Re: [PATCH v4 08/17] clk: at91: add PMC system clocks |
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On 11/10/2013 11:41, 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@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> --- > drivers/clk/at91/Makefile | 1 + > drivers/clk/at91/clk-system.c | 193 +++++++++++++++++++++++++++++++++++++++++ > drivers/clk/at91/pmc.c | 5 ++ > drivers/clk/at91/pmc.h | 3 + > 4 files changed, 202 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..603b4b1 > --- /dev/null > +++ b/drivers/clk/at91/clk-system.c > @@ -0,0 +1,193 @@ > +/* > + * drivers/clk/at91/clk-system.c > + * > + * 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 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; > +} > + > +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_ID) > + 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; > + const char *parent_name; > + > + num = of_get_child_count(np); > + if (num > (SYSTEM_MAX_ID + 1)) > + 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; > + > + parent_name = of_clk_get_parent_name(sysclknp, 0); > + > + clk = at91_clk_register_system(pmc, name, parent_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 6f08879..ce76ba6 100644 > --- a/drivers/clk/at91/pmc.c > +++ b/drivers/clk/at91/pmc.c > @@ -243,6 +243,11 @@ 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_ */ >
-- Nicolas Ferre
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