diff options
Diffstat (limited to 'drivers/clk/ti/apll.c')
| -rw-r--r-- | drivers/clk/ti/apll.c | 402 | 
1 files changed, 402 insertions, 0 deletions
diff --git a/drivers/clk/ti/apll.c b/drivers/clk/ti/apll.c new file mode 100644 index 00000000000..72d97279eae --- /dev/null +++ b/drivers/clk/ti/apll.c @@ -0,0 +1,402 @@ +/* + * OMAP APLL clock support + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * J Keerthy <j-keerthy@ti.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the + * GNU General Public License for more details. + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/string.h> +#include <linux/log2.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/clk/ti.h> +#include <linux/delay.h> + +#define APLL_FORCE_LOCK 0x1 +#define APLL_AUTO_IDLE	0x2 +#define MAX_APLL_WAIT_TRIES		1000000 + +#undef pr_fmt +#define pr_fmt(fmt) "%s: " fmt, __func__ + +static int dra7_apll_enable(struct clk_hw *hw) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); +	int r = 0, i = 0; +	struct dpll_data *ad; +	const char *clk_name; +	u8 state = 1; +	u32 v; + +	ad = clk->dpll_data; +	if (!ad) +		return -EINVAL; + +	clk_name = __clk_get_name(clk->hw.clk); + +	state <<= __ffs(ad->idlest_mask); + +	/* Check is already locked */ +	v = ti_clk_ll_ops->clk_readl(ad->idlest_reg); + +	if ((v & ad->idlest_mask) == state) +		return r; + +	v = ti_clk_ll_ops->clk_readl(ad->control_reg); +	v &= ~ad->enable_mask; +	v |= APLL_FORCE_LOCK << __ffs(ad->enable_mask); +	ti_clk_ll_ops->clk_writel(v, ad->control_reg); + +	state <<= __ffs(ad->idlest_mask); + +	while (1) { +		v = ti_clk_ll_ops->clk_readl(ad->idlest_reg); +		if ((v & ad->idlest_mask) == state) +			break; +		if (i > MAX_APLL_WAIT_TRIES) +			break; +		i++; +		udelay(1); +	} + +	if (i == MAX_APLL_WAIT_TRIES) { +		pr_warn("clock: %s failed transition to '%s'\n", +			clk_name, (state) ? "locked" : "bypassed"); +		r = -EBUSY; +	} else +		pr_debug("clock: %s transition to '%s' in %d loops\n", +			 clk_name, (state) ? "locked" : "bypassed", i); + +	return r; +} + +static void dra7_apll_disable(struct clk_hw *hw) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); +	struct dpll_data *ad; +	u8 state = 1; +	u32 v; + +	ad = clk->dpll_data; + +	state <<= __ffs(ad->idlest_mask); + +	v = ti_clk_ll_ops->clk_readl(ad->control_reg); +	v &= ~ad->enable_mask; +	v |= APLL_AUTO_IDLE << __ffs(ad->enable_mask); +	ti_clk_ll_ops->clk_writel(v, ad->control_reg); +} + +static int dra7_apll_is_enabled(struct clk_hw *hw) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); +	struct dpll_data *ad; +	u32 v; + +	ad = clk->dpll_data; + +	v = ti_clk_ll_ops->clk_readl(ad->control_reg); +	v &= ad->enable_mask; + +	v >>= __ffs(ad->enable_mask); + +	return v == APLL_AUTO_IDLE ? 0 : 1; +} + +static u8 dra7_init_apll_parent(struct clk_hw *hw) +{ +	return 0; +} + +static const struct clk_ops apll_ck_ops = { +	.enable		= &dra7_apll_enable, +	.disable	= &dra7_apll_disable, +	.is_enabled	= &dra7_apll_is_enabled, +	.get_parent	= &dra7_init_apll_parent, +}; + +static void __init omap_clk_register_apll(struct clk_hw *hw, +					  struct device_node *node) +{ +	struct clk_hw_omap *clk_hw = to_clk_hw_omap(hw); +	struct dpll_data *ad = clk_hw->dpll_data; +	struct clk *clk; + +	ad->clk_ref = of_clk_get(node, 0); +	ad->clk_bypass = of_clk_get(node, 1); + +	if (IS_ERR(ad->clk_ref) || IS_ERR(ad->clk_bypass)) { +		pr_debug("clk-ref or clk-bypass for %s not ready, retry\n", +			 node->name); +		if (!ti_clk_retry_init(node, hw, omap_clk_register_apll)) +			return; + +		goto cleanup; +	} + +	clk = clk_register(NULL, &clk_hw->hw); +	if (!IS_ERR(clk)) { +		of_clk_add_provider(node, of_clk_src_simple_get, clk); +		kfree(clk_hw->hw.init->parent_names); +		kfree(clk_hw->hw.init); +		return; +	} + +cleanup: +	kfree(clk_hw->dpll_data); +	kfree(clk_hw->hw.init->parent_names); +	kfree(clk_hw->hw.init); +	kfree(clk_hw); +} + +static void __init of_dra7_apll_setup(struct device_node *node) +{ +	struct dpll_data *ad = NULL; +	struct clk_hw_omap *clk_hw = NULL; +	struct clk_init_data *init = NULL; +	const char **parent_names = NULL; +	int i; + +	ad = kzalloc(sizeof(*ad), GFP_KERNEL); +	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL); +	init = kzalloc(sizeof(*init), GFP_KERNEL); +	if (!ad || !clk_hw || !init) +		goto cleanup; + +	clk_hw->dpll_data = ad; +	clk_hw->hw.init = init; +	clk_hw->flags = MEMMAP_ADDRESSING; + +	init->name = node->name; +	init->ops = &apll_ck_ops; + +	init->num_parents = of_clk_get_parent_count(node); +	if (init->num_parents < 1) { +		pr_err("dra7 apll %s must have parent(s)\n", node->name); +		goto cleanup; +	} + +	parent_names = kzalloc(sizeof(char *) * init->num_parents, GFP_KERNEL); +	if (!parent_names) +		goto cleanup; + +	for (i = 0; i < init->num_parents; i++) +		parent_names[i] = of_clk_get_parent_name(node, i); + +	init->parent_names = parent_names; + +	ad->control_reg = ti_clk_get_reg_addr(node, 0); +	ad->idlest_reg = ti_clk_get_reg_addr(node, 1); + +	if (!ad->control_reg || !ad->idlest_reg) +		goto cleanup; + +	ad->idlest_mask = 0x1; +	ad->enable_mask = 0x3; + +	omap_clk_register_apll(&clk_hw->hw, node); +	return; + +cleanup: +	kfree(parent_names); +	kfree(ad); +	kfree(clk_hw); +	kfree(init); +} +CLK_OF_DECLARE(dra7_apll_clock, "ti,dra7-apll-clock", of_dra7_apll_setup); + +#define OMAP2_EN_APLL_LOCKED	0x3 +#define OMAP2_EN_APLL_STOPPED	0x0 + +static int omap2_apll_is_enabled(struct clk_hw *hw) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); +	struct dpll_data *ad = clk->dpll_data; +	u32 v; + +	v = ti_clk_ll_ops->clk_readl(ad->control_reg); +	v &= ad->enable_mask; + +	v >>= __ffs(ad->enable_mask); + +	return v == OMAP2_EN_APLL_LOCKED ? 1 : 0; +} + +static unsigned long omap2_apll_recalc(struct clk_hw *hw, +				       unsigned long parent_rate) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); + +	if (omap2_apll_is_enabled(hw)) +		return clk->fixed_rate; + +	return 0; +} + +static int omap2_apll_enable(struct clk_hw *hw) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); +	struct dpll_data *ad = clk->dpll_data; +	u32 v; +	int i = 0; + +	v = ti_clk_ll_ops->clk_readl(ad->control_reg); +	v &= ~ad->enable_mask; +	v |= OMAP2_EN_APLL_LOCKED << __ffs(ad->enable_mask); +	ti_clk_ll_ops->clk_writel(v, ad->control_reg); + +	while (1) { +		v = ti_clk_ll_ops->clk_readl(ad->idlest_reg); +		if (v & ad->idlest_mask) +			break; +		if (i > MAX_APLL_WAIT_TRIES) +			break; +		i++; +		udelay(1); +	} + +	if (i == MAX_APLL_WAIT_TRIES) { +		pr_warn("%s failed to transition to locked\n", +			__clk_get_name(clk->hw.clk)); +		return -EBUSY; +	} + +	return 0; +} + +static void omap2_apll_disable(struct clk_hw *hw) +{ +	struct clk_hw_omap *clk = to_clk_hw_omap(hw); +	struct dpll_data *ad = clk->dpll_data; +	u32 v; + +	v = ti_clk_ll_ops->clk_readl(ad->control_reg); +	v &= ~ad->enable_mask; +	v |= OMAP2_EN_APLL_STOPPED << __ffs(ad->enable_mask); +	ti_clk_ll_ops->clk_writel(v, ad->control_reg); +} + +static struct clk_ops omap2_apll_ops = { +	.enable		= &omap2_apll_enable, +	.disable	= &omap2_apll_disable, +	.is_enabled	= &omap2_apll_is_enabled, +	.recalc_rate	= &omap2_apll_recalc, +}; + +static void omap2_apll_set_autoidle(struct clk_hw_omap *clk, u32 val) +{ +	struct dpll_data *ad = clk->dpll_data; +	u32 v; + +	v = ti_clk_ll_ops->clk_readl(ad->autoidle_reg); +	v &= ~ad->autoidle_mask; +	v |= val << __ffs(ad->autoidle_mask); +	ti_clk_ll_ops->clk_writel(v, ad->control_reg); +} + +#define OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP	0x3 +#define OMAP2_APLL_AUTOIDLE_DISABLE		0x0 + +static void omap2_apll_allow_idle(struct clk_hw_omap *clk) +{ +	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_LOW_POWER_STOP); +} + +static void omap2_apll_deny_idle(struct clk_hw_omap *clk) +{ +	omap2_apll_set_autoidle(clk, OMAP2_APLL_AUTOIDLE_DISABLE); +} + +static struct clk_hw_omap_ops omap2_apll_hwops = { +	.allow_idle	= &omap2_apll_allow_idle, +	.deny_idle	= &omap2_apll_deny_idle, +}; + +static void __init of_omap2_apll_setup(struct device_node *node) +{ +	struct dpll_data *ad = NULL; +	struct clk_hw_omap *clk_hw = NULL; +	struct clk_init_data *init = NULL; +	struct clk *clk; +	const char *parent_name; +	u32 val; + +	ad = kzalloc(sizeof(*ad), GFP_KERNEL); +	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL); +	init = kzalloc(sizeof(*init), GFP_KERNEL); + +	if (!ad || !clk_hw || !init) +		goto cleanup; + +	clk_hw->dpll_data = ad; +	clk_hw->hw.init = init; +	init->ops = &omap2_apll_ops; +	init->name = node->name; +	clk_hw->ops = &omap2_apll_hwops; + +	init->num_parents = of_clk_get_parent_count(node); +	if (init->num_parents != 1) { +		pr_err("%s must have one parent\n", node->name); +		goto cleanup; +	} + +	parent_name = of_clk_get_parent_name(node, 0); +	init->parent_names = &parent_name; + +	if (of_property_read_u32(node, "ti,clock-frequency", &val)) { +		pr_err("%s missing clock-frequency\n", node->name); +		goto cleanup; +	} +	clk_hw->fixed_rate = val; + +	if (of_property_read_u32(node, "ti,bit-shift", &val)) { +		pr_err("%s missing bit-shift\n", node->name); +		goto cleanup; +	} + +	clk_hw->enable_bit = val; +	ad->enable_mask = 0x3 << val; +	ad->autoidle_mask = 0x3 << val; + +	if (of_property_read_u32(node, "ti,idlest-shift", &val)) { +		pr_err("%s missing idlest-shift\n", node->name); +		goto cleanup; +	} + +	ad->idlest_mask = 1 << val; + +	ad->control_reg = ti_clk_get_reg_addr(node, 0); +	ad->autoidle_reg = ti_clk_get_reg_addr(node, 1); +	ad->idlest_reg = ti_clk_get_reg_addr(node, 2); + +	if (!ad->control_reg || !ad->autoidle_reg || !ad->idlest_reg) +		goto cleanup; + +	clk = clk_register(NULL, &clk_hw->hw); +	if (!IS_ERR(clk)) { +		of_clk_add_provider(node, of_clk_src_simple_get, clk); +		kfree(init); +		return; +	} +cleanup: +	kfree(ad); +	kfree(clk_hw); +	kfree(init); +} +CLK_OF_DECLARE(omap2_apll_clock, "ti,omap2-apll-clock", +	       of_omap2_apll_setup);  | 
