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    SubjectRe: [PATCH v4 09/17] clk: at91: add PMC peripheral clocks
    On 11/10/2013 11:44, 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@overkiz.com>

    Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

    > ---
    > drivers/clk/at91/Makefile | 2 +-
    > drivers/clk/at91/clk-peripheral.c | 407 +++++++++++++++++++++++++++++++++++++
    > drivers/clk/at91/pmc.c | 9 +
    > drivers/clk/at91/pmc.h | 5 +
    > 4 files changed, 422 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..2dce2e2
    > --- /dev/null
    > +++ b/drivers/clk/at91/clk-peripheral.c
    > @@ -0,0 +1,407 @@
    > +/*
    > + * drivers/clk/at91/clk-peripheral.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 PERIPHERAL_MAX 64
    > +
    > +#define PERIPHERAL_AT91RM9200 0
    > +#define PERIPHERAL_AT91SAM9X5 1
    > +
    > +#define PERIPHERAL_ID_MIN 2
    > +#define PERIPHERAL_ID_MAX 31
    > +#define PERIPHERAL_MASK(id) (1 << ((id) & PERIPHERAL_ID_MAX))
    > +
    > +#define PERIPHERAL_RSHIFT_MASK 0x3
    > +#define PERIPHERAL_RSHIFT(val) (((val) >> 16) & PERIPHERAL_RSHIFT_MASK)
    > +
    > +struct clk_peripheral {
    > + struct clk_hw hw;
    > + struct at91_pmc *pmc;
    > + u32 id;
    > +};
    > +
    > +#define to_clk_peripheral(hw) container_of(hw, struct clk_peripheral, hw)
    > +
    > +struct clk_sam9x5_peripheral {
    > + struct clk_hw hw;
    > + struct at91_pmc *pmc;
    > + u32 id;
    > + u8 div;
    > + u8 have_div_support;
    > +};
    > +
    > +#define to_clk_sam9x5_peripheral(hw) \
    > + container_of(hw, struct clk_sam9x5_peripheral, hw)
    > +
    > +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;
    > + u32 id = periph->id;
    > +
    > + if (id < PERIPHERAL_ID_MIN)
    > + return 0;
    > + if (id > PERIPHERAL_ID_MAX)
    > + offset = AT91_PMC_PCER1;
    > + pmc_write(pmc, offset, PERIPHERAL_MASK(id));
    > + 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;
    > + u32 id = periph->id;
    > +
    > + if (id < PERIPHERAL_ID_MIN)
    > + return;
    > + if (id > PERIPHERAL_ID_MAX)
    > + offset = AT91_PMC_PCDR1;
    > + pmc_write(pmc, offset, PERIPHERAL_MASK(id));
    > +}
    > +
    > +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;
    > + u32 id = periph->id;
    > +
    > + if (id < PERIPHERAL_ID_MIN)
    > + return 1;
    > + if (id > PERIPHERAL_ID_MAX)
    > + offset = AT91_PMC_PCSR1;
    > + return !!(pmc_read(pmc, offset) & PERIPHERAL_MASK(id));
    > +}
    > +
    > +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 || id > PERIPHERAL_ID_MAX)
    > + return ERR_PTR(-EINVAL);
    > +
    > + 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 < PERIPHERAL_ID_MIN)
    > + 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 < PERIPHERAL_ID_MIN)
    > + 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 < PERIPHERAL_ID_MIN)
    > + 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 < PERIPHERAL_ID_MIN || !periph->have_div_support)
    > + return parent_rate;
    > + pmc_lock(pmc);
    > + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID));
    > + shift = PERIPHERAL_RSHIFT(pmc_read(pmc, AT91_PMC_PCR));
    > + 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);
    > + 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 ce76ba6..8e27e92 100644
    > --- a/drivers/clk/at91/pmc.c
    > +++ b/drivers/clk/at91/pmc.c
    > @@ -248,6 +248,15 @@ 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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