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Message-ID: <5254280B.6050705@atmel.com>
Date: Tue, 8 Oct 2013 17:43:07 +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 11/19] clk: at91: add PMC peripheral clocks
On 08/08/2013 08:16, Boris BREZILLON :
> This patch adds new at91 peripheral clock implementation using common clk
> framework.
>
> Almost all peripherals provided by at91 SoCs need a clock to work properly.
> This clock is enabled/disabled using PCER/PCDR resgisters.
>
> Each peripheral is given an id (see atmel's datasheets) which is used to
> define and reference peripheral clocks.
>
> Some new SoCs (at91sam9x5 and sama5d3) provide a new register (PCR) where you
> can configure the peripheral clock as a division of the master clock.
> This will help reducing the peripherals power comsumption.
>
> Signed-off-by: Boris BREZILLON <b.brezillon@...rkiz.com>
> ---
> drivers/clk/at91/Makefile | 2 +-
> drivers/clk/at91/clk-peripheral.c | 401 +++++++++++++++++++++++++++++++++++++
> drivers/clk/at91/pmc.c | 9 +
> drivers/clk/at91/pmc.h | 5 +
> 4 files changed, 416 insertions(+), 1 deletion(-)
> create mode 100644 drivers/clk/at91/clk-peripheral.c
>
> diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
> index c2b7068..04deba3 100644
> --- a/drivers/clk/at91/Makefile
> +++ b/drivers/clk/at91/Makefile
> @@ -4,4 +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
> +obj-y += clk-system.o clk-peripheral.o
> diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c
> new file mode 100644
> index 0000000..1612739
> --- /dev/null
> +++ b/drivers/clk/at91/clk-peripheral.c
> @@ -0,0 +1,401 @@
> +/*
> + * drivers/clk/at91/clk-peripheral.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 PERIPHERAL_MAX 64
> +
> +#define PERIPHERAL_AT91RM9200 0
> +#define PERIPHERAL_AT91SAM9X5 1
> +
> +#define to_clk_peripheral(hw) container_of(hw, struct clk_peripheral, hw)
> +struct clk_peripheral {
> + struct clk_hw hw;
> + struct at91_pmc *pmc;
> + u32 id;
> +};
> +
> +#define to_clk_sam9x5_peripheral(hw) \
> + container_of(hw, struct clk_sam9x5_peripheral, hw)
> +struct clk_sam9x5_peripheral {
> + struct clk_hw hw;
> + struct at91_pmc *pmc;
> + u32 id;
> + u8 div;
> + u8 have_div_support;
> +};
> +
> +static int clk_peripheral_enable(struct clk_hw *hw)
> +{
> + struct clk_peripheral *periph = to_clk_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> + int offset = AT91_PMC_PCER;
> +
> + if (periph->id < 2)
> + return 0;
> + if (periph->id > 31)
define constants
> + offset = AT91_PMC_PCER1;
> + pmc_write(pmc, offset, 1 << (periph->id & 31));
A little macro here.
> + return 0;
> +}
> +
> +static void clk_peripheral_disable(struct clk_hw *hw)
> +{
> + struct clk_peripheral *periph = to_clk_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> + int offset = AT91_PMC_PCDR;
> +
> + if (periph->id < 2)
> + return;
> + if (periph->id > 31)
> + offset = AT91_PMC_PCDR1;
> + pmc_write(pmc, offset, 1 << (periph->id & 31));
Ditto
> +}
> +
> +static int clk_peripheral_is_enabled(struct clk_hw *hw)
> +{
> + struct clk_peripheral *periph = to_clk_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> + int offset = AT91_PMC_PCSR;
> +
> + if (periph->id < 2)
> + return 1;
> + if (periph->id > 31)
> + offset = AT91_PMC_PCSR1;
> + return !!(pmc_read(pmc, offset) & (1 << (periph->id & 31)));
Ditto
> +}
> +
> +static const struct clk_ops peripheral_ops = {
> + .enable = clk_peripheral_enable,
> + .disable = clk_peripheral_disable,
> + .is_enabled = clk_peripheral_is_enabled,
> +};
> +
> +static struct clk * __init
> +at91_clk_register_peripheral(struct at91_pmc *pmc, const char *name,
> + const char *parent_name, u32 id)
> +{
> + struct clk_peripheral *periph;
> + struct clk *clk = NULL;
> + struct clk_init_data init;
> +
> + if (!pmc || !name || !parent_name)
> + return ERR_PTR(-EINVAL);
> +
> + id &= 31;
Ditto
> + periph = kzalloc(sizeof(*periph), GFP_KERNEL);
> + if (!periph)
> + return ERR_PTR(-ENOMEM);
> +
> + init.name = name;
> + init.ops = &peripheral_ops;
> + init.parent_names = (parent_name ? &parent_name : NULL);
> + init.num_parents = (parent_name ? 1 : 0);
> + init.flags = 0;
> +
> + periph->id = id;
> + periph->hw.init = &init;
> + periph->pmc = pmc;
> +
> + clk = clk_register(NULL, &periph->hw);
> + if (IS_ERR(clk))
> + kfree(periph);
> +
> + return clk;
> +}
> +
> +static int clk_sam9x5_peripheral_enable(struct clk_hw *hw)
> +{
> + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> +
> + if (periph->id < 2)
> + return 0;
> + pmc_write(pmc, AT91_PMC_PCR,
> + (periph->id & AT91_PMC_PCR_PID) |
> + AT91_PMC_PCR_CMD |
> + AT91_PMC_PCR_DIV(periph->div) |
> + AT91_PMC_PCR_EN);
> + return 0;
> +}
> +
> +static void clk_sam9x5_peripheral_disable(struct clk_hw *hw)
> +{
> + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> +
> + if (periph->id < 2)
> + return;
> +
> + pmc_write(pmc, AT91_PMC_PCR,
> + (periph->id & AT91_PMC_PCR_PID) |
> + AT91_PMC_PCR_CMD);
> +}
> +
> +static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw)
> +{
> + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> + int ret;
> +
> + if (periph->id < 2)
> + return 1;
> + pmc_lock(pmc);
> + pmc_write(pmc, AT91_PMC_PCR,
> + (periph->id & AT91_PMC_PCR_PID));
> + ret = !!(pmc_read(pmc, AT91_PMC_PCR) & AT91_PMC_PCR_EN);
> + pmc_unlock(pmc);
> +
> + return ret;
> +}
> +
> +static unsigned long
> +clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw,
> + unsigned long parent_rate)
> +{
> + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
> + struct at91_pmc *pmc = periph->pmc;
> + u32 shift;
> +
> + if (periph->id < 2 || !periph->have_div_support)
> + return parent_rate;
> + pmc_lock(pmc);
> + pmc_write(pmc, AT91_PMC_PCR,
> + (periph->id & AT91_PMC_PCR_PID));
> + shift = (pmc_read(pmc, AT91_PMC_PCR) >> 16) & 0x3;
define constants
> + pmc_unlock(pmc);
> + return parent_rate >> shift;
> +}
> +
> +static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw,
> + unsigned long rate,
> + unsigned long *parent_rate)
> +{
> + int shift;
> + unsigned long best_rate;
> + unsigned long best_diff;
> + unsigned long cur_rate;
> + unsigned long cur_diff;
> + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
> +
> + if (periph->id < 2 || !periph->have_div_support)
> + return *parent_rate;
> + if (rate >= *parent_rate)
> + return rate;
> + best_diff = *parent_rate - rate;
> + best_rate = *parent_rate;
> + for (shift = 1; shift < 4; shift++) {
> + cur_rate = *parent_rate >> shift;
> + if (cur_rate < rate)
> + cur_diff = rate - cur_rate;
> + else
> + cur_diff = cur_rate - rate;
> + if (cur_diff < best_diff) {
> + best_diff = cur_diff;
> + best_rate = cur_rate;
> + }
> + if (!best_diff || cur_rate < rate)
> + break;
> + }
> + return best_rate;
> +}
> +
> +static int clk_sam9x5_peripheral_set_rate(struct clk_hw *hw,
> + unsigned long rate,
> + unsigned long parent_rate)
> +{
> + int shift;
> + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);
> + if (periph->id < 2 || !periph->have_div_support) {
> + if (parent_rate == rate)
> + return 0;
> + else
> + return -EINVAL;
> + }
> +
> + for (shift = 0; shift < 4; shift++) {
> + if (parent_rate >> shift == rate) {
> + periph->div = shift;
> + return 0;
> + }
> + }
> +
> + return -EINVAL;
> +}
> +
> +static const struct clk_ops sam9x5_peripheral_ops = {
> + .enable = clk_sam9x5_peripheral_enable,
> + .disable = clk_sam9x5_peripheral_disable,
> + .is_enabled = clk_sam9x5_peripheral_is_enabled,
> + .recalc_rate = clk_sam9x5_peripheral_recalc_rate,
> + .round_rate = clk_sam9x5_peripheral_round_rate,
> + .set_rate = clk_sam9x5_peripheral_set_rate,
> +};
> +
> +static struct clk * __init
> +at91_clk_register_sam9x5_peripheral(struct at91_pmc *pmc, const char *name,
> + const char *parent_name, u32 id,
> + u32 default_div)
> +{
> + struct clk_sam9x5_peripheral *periph;
> + struct clk *clk = NULL;
> + struct clk_init_data init;
> +
> + if (!pmc || !name || !parent_name)
> + return ERR_PTR(-EINVAL);
> +
> + periph = kzalloc(sizeof(*periph), GFP_KERNEL);
> + if (!periph)
> + return ERR_PTR(-ENOMEM);
> +
> + init.name = name;
> + init.ops = &sam9x5_peripheral_ops;
> + init.parent_names = (parent_name ? &parent_name : NULL);
> + init.num_parents = (parent_name ? 1 : 0);
> + init.flags = CLK_SET_RATE_GATE;
> +
> + periph->id = id;
> + periph->hw.init = &init;
> + periph->div = default_div;
> + periph->pmc = pmc;
> +
> + clk = clk_register(NULL, &periph->hw);
> +
Ditto
> + if (IS_ERR(clk))
> + kfree(periph);
> +
> + return clk;
> +}
> +
> +struct clk_periph_data {
> + struct clk **clks;
> + u8 *ids;
> + unsigned int clk_num;
> +};
> +
> +static struct clk * __init
> +of_clk_src_periph_get(struct of_phandle_args *clkspec, void *data)
> +{
> + struct clk_periph_data *clk_data = data;
> + unsigned int id = clkspec->args[0];
> + int i;
> +
> + if (id >= PERIPHERAL_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_periph_setup(struct device_node *np, struct at91_pmc *pmc, u8 type)
> +{
> + int num;
> + int i;
> + u32 id;
> + struct clk *clk;
> + const char *parent_name;
> + const char *name;
> + u32 divisor;
> + struct clk **clks;
> + u8 *ids;
> + struct clk_periph_data *clktab;
> + struct device_node *periphclknp;
> +
> + parent_name = of_clk_get_parent_name(np, 0);
> + if (!parent_name)
> + return;
> +
> + num = of_get_child_count(np);
> + if (!num || num > PERIPHERAL_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, periphclknp) {
> + name = periphclknp->name;
> +
> + if (of_property_read_u32(periphclknp, "atmel,clk-id", &id))
> + goto out_free_clks;
> + if (id >= PERIPHERAL_MAX)
> + goto out_free_clks;
> +
> + if (type == PERIPHERAL_AT91RM9200) {
> + clk = at91_clk_register_peripheral(pmc, name,
> + parent_name, id);
> + } else {
> + if (of_property_read_u32(periphclknp,
> + "atmel,clk-default-divisor",
> + &divisor))
> + divisor = 0;
> +
> + clk = at91_clk_register_sam9x5_peripheral(pmc, name,
> + parent_name,
> + id,
> + divisor);
> + }
> + if (IS_ERR(clk))
> + goto out_free_clks;
> +
> + clks[i] = clk;
> + ids[i++] = id;
> + }
> +
> + clktab->clk_num = num;
> + clktab->clks = clks;
> + clktab->ids = ids;
> + of_clk_add_provider(np, of_clk_src_periph_get, clktab);
> + return;
> +
> +out_free_clks:
> + kfree(clks);
> +out_free_ids:
> + kfree(ids);
> +out_free_clktab:
> + kfree(clktab);
> +}
> +
> +void __init of_at91rm9200_clk_periph_setup(struct device_node *np,
> + struct at91_pmc *pmc)
> +{
> + of_at91_clk_periph_setup(np, pmc, PERIPHERAL_AT91RM9200);
> +}
> +
> +void __init of_at91sam9x5_clk_periph_setup(struct device_node *np,
> + struct at91_pmc *pmc)
> +{
> + of_at91_clk_periph_setup(np, pmc, PERIPHERAL_AT91SAM9X5);
> +}
> diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
> index c674ef2..1a56f1c 100644
> --- a/drivers/clk/at91/pmc.c
> +++ b/drivers/clk/at91/pmc.c
> @@ -256,6 +256,15 @@ static const struct of_device_id pmc_clk_ids[] __initdata = {
> .compatible = "atmel,at91rm9200-clk-system",
> .data = of_at91rm9200_clk_sys_setup,
> },
> + /* Peripheral clocks */
> + {
> + .compatible = "atmel,at91rm9200-clk-peripheral",
> + .data = of_at91rm9200_clk_periph_setup,
> + },
> + {
> + .compatible = "atmel,at91sam9x5-clk-peripheral",
> + .data = of_at91sam9x5_clk_periph_setup,
> + },
> { /*sentinel*/ }
> };
>
> diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
> index f88ef41..08c30fb 100644
> --- a/drivers/clk/at91/pmc.h
> +++ b/drivers/clk/at91/pmc.h
> @@ -77,4 +77,9 @@ extern void __init of_at91sam9x5_clk_master_setup(struct device_node *np,
> extern void __init of_at91rm9200_clk_sys_setup(struct device_node *np,
> struct at91_pmc *pmc);
>
> +extern void __init of_at91rm9200_clk_periph_setup(struct device_node *np,
> + struct at91_pmc *pmc);
> +extern void __init of_at91sam9x5_clk_periph_setup(struct device_node *np,
> + struct at91_pmc *pmc);
> +
> #endif /* __PMC_H_ */
>
--
Nicolas Ferre
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