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@xxxxxxxxxxx> Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx> --- drivers/clk/at91/Makefile | 2 +- drivers/clk/at91/clk-peripheral.c | 412 +++++++++++++++++++++++++++++++++++++ drivers/clk/at91/pmc.c | 9 + drivers/clk/at91/pmc.h | 5 + 4 files changed, 427 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..15c9518 --- /dev/null +++ b/drivers/clk/at91/clk-peripheral.c @@ -0,0 +1,412 @@ +/* + * drivers/clk/at91/clk-peripheral.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 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) + +#define PERIPHERAL_MAX_SHIFT 4 + +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; + struct clk_range range; + u32 id; + u32 div; + bool auto_div; +}; + +#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 void clk_sam9x5_peripheral_autodiv(struct clk_sam9x5_peripheral *periph) +{ + struct clk *parent; + unsigned long parent_rate; + int shift = 0; + + if (!periph->auto_div) + return; + + if (periph->range.max) { + parent = clk_get_parent_by_index(periph->hw.clk, 0); + parent_rate = __clk_get_rate(parent); + if (!parent_rate) + return; + + for (; shift < PERIPHERAL_MAX_SHIFT; shift++) { + if (parent_rate >> shift <= periph->range.max) + break; + } + } + + periph->auto_div = false; + periph->div = shift; +} + +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 tmp; + + if (periph->id < PERIPHERAL_ID_MIN) + return parent_rate; + + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID)); + tmp = pmc_read(pmc, AT91_PMC_PCR); + pmc_unlock(pmc); + + if (tmp & AT91_PMC_PCR_EN) { + periph->div = PERIPHERAL_RSHIFT(tmp); + periph->auto_div = false; + } else { + clk_sam9x5_peripheral_autodiv(periph); + } + + return parent_rate >> periph->div; +} + +static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw, + unsigned long rate, + unsigned long *parent_rate) +{ + int shift = 0; + unsigned long best_rate; + unsigned long best_diff; + unsigned long cur_rate = *parent_rate; + unsigned long cur_diff; + struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); + + if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max) + return *parent_rate; + + if (periph->range.max) { + for (; shift < PERIPHERAL_MAX_SHIFT; shift++) { + cur_rate = *parent_rate >> shift; + if (cur_rate <= periph->range.max) + break; + } + } + + if (rate >= cur_rate) + return cur_rate; + + best_diff = cur_rate - rate; + best_rate = cur_rate; + for (; shift < PERIPHERAL_MAX_SHIFT; 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 < PERIPHERAL_ID_MIN || !periph->range.max) { + if (parent_rate == rate) + return 0; + else + return -EINVAL; + } + + if (periph->range.max && rate > periph->range.max) + return -EINVAL; + + for (shift = 0; shift < PERIPHERAL_MAX_SHIFT; shift++) { + if (parent_rate >> shift == rate) { + periph->auto_div = false; + 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, + const struct clk_range *range) +{ + 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 = 0; + + periph->id = id; + periph->hw.init = &init; + periph->div = 0; + periph->pmc = pmc; + periph->auto_div = true; + periph->range = *range; + + clk = clk_register(NULL, &periph->hw); + if (IS_ERR(clk)) + kfree(periph); + else + clk_sam9x5_peripheral_autodiv(periph); + + return clk; +} + +static void __init +of_at91_clk_periph_setup(struct device_node *np, struct at91_pmc *pmc, u8 type) +{ + int num; + u32 id; + struct clk *clk; + const char *parent_name; + const char *name; + 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; + + for_each_child_of_node(np, periphclknp) { + if (of_property_read_u32(periphclknp, "reg", &id)) + continue; + + if (id >= PERIPHERAL_MAX) + continue; + + if (of_property_read_string(np, "clock-output-names", &name)) + name = periphclknp->name; + + if (type == PERIPHERAL_AT91RM9200) { + clk = at91_clk_register_peripheral(pmc, name, + parent_name, id); + } else { + struct clk_range range = CLK_RANGE(0, 0); + + of_at91_get_clk_range(periphclknp, + "atmel,clk-output-range", + &range); + + clk = at91_clk_register_sam9x5_peripheral(pmc, name, + parent_name, + id, &range); + } + + if (IS_ERR(clk)) + continue; + + of_clk_add_provider(periphclknp, of_clk_src_simple_get, clk); + } +} + +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 6adc5be..09dfa63 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c @@ -271,6 +271,15 @@ 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 9c8a397..a09212b 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -80,4 +80,9 @@ 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_ */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html