diff options
Diffstat (limited to 'drivers/clk/at91/clk-peripheral.c')
| -rw-r--r-- | drivers/clk/at91/clk-peripheral.c | 410 | 
1 files changed, 410 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c new file mode 100644 index 00000000000..597fed423d7 --- /dev/null +++ b/drivers/clk/at91/clk-peripheral.c @@ -0,0 +1,410 @@ +/* + *  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) + +#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); +}  | 
