diff options
| -rw-r--r-- | drivers/clk/at91/Makefile | 2 | ||||
| -rw-r--r-- | drivers/clk/at91/clk-programmable.c | 366 | ||||
| -rw-r--r-- | drivers/clk/at91/pmc.c | 15 | ||||
| -rw-r--r-- | drivers/clk/at91/pmc.h | 9 |
4 files changed, 392 insertions, 0 deletions
diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile index 04deba3..3873b62 100644 --- a/drivers/clk/at91/Makefile +++ b/drivers/clk/at91/Makefile @@ -5,3 +5,5 @@ obj-y += pmc.o obj-y += clk-main.o clk-pll.o clk-plldiv.o clk-master.o obj-y += clk-system.o clk-peripheral.o + +obj-$(CONFIG_AT91_PROGRAMMABLE_CLOCKS) += clk-programmable.o diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c new file mode 100644 index 0000000..fd792b2 --- /dev/null +++ b/drivers/clk/at91/clk-programmable.c @@ -0,0 +1,366 @@ +/* + * 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/of_irq.h> +#include <linux/io.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/interrupt.h> +#include <linux/irq.h> + +#include "pmc.h" + +#define PROG_SOURCE_MAX 5 +#define PROG_ID_MAX 7 + +#define PROG_STATUS_MASK(id) (1 << ((id) + 8)) +#define PROG_PRES_MASK 0x7 +#define PROG_MAX_RM9200_CSS 3 + +struct clk_programmable_layout { + u8 pres_shift; + u8 css_mask; + u8 have_slck_mck; +}; + +struct clk_programmable { + struct clk_hw hw; + struct at91_pmc *pmc; + unsigned int irq; + wait_queue_head_t wait; + u8 id; + u8 css; + u8 pres; + u8 slckmck; + const struct clk_programmable_layout *layout; +}; + +#define to_clk_programmable(hw) container_of(hw, struct clk_programmable, hw) + + +static irqreturn_t clk_programmable_irq_handler(int irq, void *dev_id) +{ + struct clk_programmable *prog = (struct clk_programmable *)dev_id; + + wake_up(&prog->wait); + + return IRQ_HANDLED; +} + +static int clk_programmable_prepare(struct clk_hw *hw) +{ + u32 tmp; + struct clk_programmable *prog = to_clk_programmable(hw); + struct at91_pmc *pmc = prog->pmc; + const struct clk_programmable_layout *layout = prog->layout; + u8 id = prog->id; + u32 mask = PROG_STATUS_MASK(id); + + tmp = prog->css | (prog->pres << layout->pres_shift); + if (layout->have_slck_mck && prog->slckmck) + tmp |= AT91_PMC_CSSMCK_MCK; + + pmc_write(pmc, AT91_PMC_PCKR(id), tmp); + + while (!(pmc_read(pmc, AT91_PMC_SR) & mask)) + wait_event(prog->wait, pmc_read(pmc, AT91_PMC_SR) & mask); + + return 0; +} + +static int clk_programmable_is_ready(struct clk_hw *hw) +{ + struct clk_programmable *prog = to_clk_programmable(hw); + struct at91_pmc *pmc = prog->pmc; + + return !!(pmc_read(pmc, AT91_PMC_SR) & AT91_PMC_PCKR(prog->id)); +} + +static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u32 tmp; + struct clk_programmable *prog = to_clk_programmable(hw); + struct at91_pmc *pmc = prog->pmc; + const struct clk_programmable_layout *layout = prog->layout; + + tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id)); + prog->pres = (tmp >> layout->pres_shift) & PROG_PRES_MASK; + + return parent_rate >> prog->pres; +} + +static long clk_programmable_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned long best_rate = *parent_rate; + unsigned long best_diff; + unsigned long new_diff; + unsigned long cur_rate; + int shift = shift; + + if (rate > *parent_rate) + return *parent_rate; + else + best_diff = *parent_rate - rate; + + if (!best_diff) + return best_rate; + + for (shift = 1; shift < PROG_PRES_MASK; shift++) { + cur_rate = *parent_rate >> shift; + + if (cur_rate > rate) + new_diff = cur_rate - rate; + else + new_diff = rate - cur_rate; + + if (!new_diff) + return cur_rate; + + if (new_diff < best_diff) { + best_diff = new_diff; + best_rate = cur_rate; + } + + if (rate > cur_rate) + break; + } + + return best_rate; +} + +static int clk_programmable_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_programmable *prog = to_clk_programmable(hw); + const struct clk_programmable_layout *layout = prog->layout; + if (index > layout->css_mask) { + if (index > PROG_MAX_RM9200_CSS && layout->have_slck_mck) { + prog->css = 0; + prog->slckmck = 1; + return 0; + } else { + return -EINVAL; + } + } + + prog->css = index; + return 0; +} + +static u8 clk_programmable_get_parent(struct clk_hw *hw) +{ + u32 tmp; + u8 ret; + struct clk_programmable *prog = to_clk_programmable(hw); + struct at91_pmc *pmc = prog->pmc; + const struct clk_programmable_layout *layout = prog->layout; + + tmp = pmc_read(pmc, AT91_PMC_PCKR(prog->id)); + prog->css = tmp & layout->css_mask; + ret = prog->css; + if (layout->have_slck_mck) { + prog->slckmck = !!(tmp & AT91_PMC_CSSMCK_MCK); + if (prog->slckmck && !ret) + ret = PROG_MAX_RM9200_CSS + 1; + } + + return ret; +} + +static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_programmable *prog = to_clk_programmable(hw); + unsigned long best_rate = parent_rate; + unsigned long best_diff; + unsigned long new_diff; + unsigned long cur_rate; + int shift = 0; + + if (rate > parent_rate) + return parent_rate; + else + best_diff = parent_rate - rate; + + if (!best_diff) { + prog->pres = shift; + return 0; + } + + for (shift = 1; shift < PROG_PRES_MASK; shift++) { + cur_rate = parent_rate >> shift; + + if (cur_rate > rate) + new_diff = cur_rate - rate; + else + new_diff = rate - cur_rate; + + if (!new_diff) + break; + + if (new_diff < best_diff) { + best_diff = new_diff; + best_rate = cur_rate; + } + + if (rate > cur_rate) + break; + } + + prog->pres = shift; + return 0; +} + +static const struct clk_ops programmable_ops = { + .prepare = clk_programmable_prepare, + .is_prepared = clk_programmable_is_ready, + .recalc_rate = clk_programmable_recalc_rate, + .round_rate = clk_programmable_round_rate, + .get_parent = clk_programmable_get_parent, + .set_parent = clk_programmable_set_parent, + .set_rate = clk_programmable_set_rate, +}; + +static struct clk * __init +at91_clk_register_programmable(struct at91_pmc *pmc, unsigned int irq, + const char *name, const char **parent_names, + u8 num_parents, u8 id, + const struct clk_programmable_layout *layout) +{ + int ret; + struct clk_programmable *prog; + struct clk *clk = NULL; + struct clk_init_data init; + char irq_name[11]; + + if (id > PROG_ID_MAX) + return ERR_PTR(-EINVAL); + + prog = kzalloc(sizeof(*prog), GFP_KERNEL); + if (!prog) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &programmable_ops; + init.parent_names = parent_names; + init.num_parents = num_parents; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + + prog->id = id; + prog->layout = layout; + prog->hw.init = &init; + prog->pmc = pmc; + prog->irq = irq; + init_waitqueue_head(&prog->wait); + irq_set_status_flags(prog->irq, IRQ_NOAUTOEN); + snprintf(irq_name, sizeof(irq_name), "clk-prog%d", id); + ret = request_irq(prog->irq, clk_programmable_irq_handler, + IRQF_TRIGGER_HIGH, irq_name, prog); + if (ret) + return ERR_PTR(ret); + + clk = clk_register(NULL, &prog->hw); + if (IS_ERR(clk)) + kfree(prog); + + return clk; +} + +static const struct clk_programmable_layout at91rm9200_programmable_layout = { + .pres_shift = 2, + .css_mask = 0x3, + .have_slck_mck = 0, +}; + +static const struct clk_programmable_layout at91sam9g45_programmable_layout = { + .pres_shift = 2, + .css_mask = 0x3, + .have_slck_mck = 1, +}; + +static const struct clk_programmable_layout at91sam9x5_programmable_layout = { + .pres_shift = 4, + .css_mask = 0x7, + .have_slck_mck = 0, +}; + +static void __init +of_at91_clk_prog_setup(struct device_node *np, struct at91_pmc *pmc, + const struct clk_programmable_layout *layout) +{ + int num; + u32 id; + int i; + unsigned int irq; + struct clk *clk; + int num_parents; + const char *parent_names[PROG_SOURCE_MAX]; + const char *name; + struct device_node *progclknp; + + num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); + if (num_parents <= 0 || num_parents > PROG_SOURCE_MAX) + return; + + for (i = 0; i < num_parents; ++i) { + parent_names[i] = of_clk_get_parent_name(np, i); + if (!parent_names[i]) + return; + } + + num = of_get_child_count(np); + if (!num || num > (PROG_ID_MAX + 1)) + return; + + for_each_child_of_node(np, progclknp) { + if (of_property_read_u32(progclknp, "reg", &id)) + continue; + + if (of_property_read_string(np, "clock-output-names", &name)) + name = progclknp->name; + + irq = irq_of_parse_and_map(progclknp, 0); + if (!irq) + continue; + + clk = at91_clk_register_programmable(pmc, irq, name, + parent_names, num_parents, + id, layout); + if (IS_ERR(clk)) + continue; + + of_clk_add_provider(progclknp, of_clk_src_simple_get, clk); + } +} + + +void __init of_at91rm9200_clk_prog_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_prog_setup(np, pmc, &at91rm9200_programmable_layout); +} + +void __init of_at91sam9g45_clk_prog_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_prog_setup(np, pmc, &at91sam9g45_programmable_layout); +} + +void __init of_at91sam9x5_clk_prog_setup(struct device_node *np, + struct at91_pmc *pmc) +{ + of_at91_clk_prog_setup(np, pmc, &at91sam9x5_programmable_layout); +} diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c index afdfeb2..d0a1f93 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c @@ -278,6 +278,21 @@ static const struct of_device_id pmc_clk_ids[] __initdata = { .compatible = "atmel,at91sam9x5-clk-peripheral", .data = of_at91sam9x5_clk_periph_setup, }, + /* Programmable clocks */ +#if defined(CONFIG_AT91_PROGRAMMABLE_CLOCKS) + { + .compatible = "atmel,at91rm9200-clk-programmable", + .data = of_at91rm9200_clk_prog_setup, + }, + { + .compatible = "atmel,at91sam9g45-clk-programmable", + .data = of_at91sam9g45_clk_prog_setup, + }, + { + .compatible = "atmel,at91sam9x5-clk-programmable", + .data = of_at91sam9x5_clk_prog_setup, + }, +#endif { /*sentinel*/ } }; diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h index a09212b..6eeed49 100644 --- a/drivers/clk/at91/pmc.h +++ b/drivers/clk/at91/pmc.h @@ -85,4 +85,13 @@ extern void __init of_at91rm9200_clk_periph_setup(struct device_node *np, extern void __init of_at91sam9x5_clk_periph_setup(struct device_node *np, struct at91_pmc *pmc); +#if defined(CONFIG_AT91_PROGRAMMABLE_CLOCKS) +extern void __init of_at91rm9200_clk_prog_setup(struct device_node *np, + struct at91_pmc *pmc); +extern void __init of_at91sam9g45_clk_prog_setup(struct device_node *np, + struct at91_pmc *pmc); +extern void __init of_at91sam9x5_clk_prog_setup(struct device_node *np, + struct at91_pmc *pmc); +#endif + #endif /* __PMC_H_ */ |