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Message-ID: <5254259F.9030907@atmel.com>
Date: Tue, 8 Oct 2013 17:32:47 +0200
From: Nicolas Ferre <nicolas.ferre@...el.com>
To: Boris BREZILLON <b.brezillon@...rkiz.com>,
Grant Likely <grant.likely@...aro.org>,
Rob Herring <rob.herring@...xeda.com>,
Rob Landley <rob@...dley.net>,
Andrew Victor <linux@...im.org.za>,
"Jean-Christophe Plagniol-Villard" <plagnioj@...osoft.com>,
Russell King <linux@....linux.org.uk>,
Mike Turquette <mturquette@...aro.org>,
"Felipe Balbi" <balbi@...com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Ludovic Desroches <ludovic.desroches@...el.com>,
Josh Wu <josh.wu@...el.com>,
Richard Genoud <richard.genoud@...il.com>
CC: <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3 09/19] clk: at91: add PMC system clocks
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@...rkiz.com>
> ---
> 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@...rkiz.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 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_ */
>
--
Nicolas Ferre
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