diff options
Diffstat (limited to 'drivers/clk/at91/clk-slow.c')
| -rw-r--r-- | drivers/clk/at91/clk-slow.c | 467 | 
1 files changed, 467 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-slow.c b/drivers/clk/at91/clk-slow.c new file mode 100644 index 00000000000..0300c46ee24 --- /dev/null +++ b/drivers/clk/at91/clk-slow.c @@ -0,0 +1,467 @@ +/* + * drivers/clk/at91/clk-slow.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/delay.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/io.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/sched.h> +#include <linux/wait.h> + +#include "pmc.h" +#include "sckc.h" + +#define SLOW_CLOCK_FREQ		32768 +#define SLOWCK_SW_CYCLES	5 +#define SLOWCK_SW_TIME_USEC	((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \ +				 SLOW_CLOCK_FREQ) + +#define	AT91_SCKC_CR			0x00 +#define		AT91_SCKC_RCEN		(1 << 0) +#define		AT91_SCKC_OSC32EN	(1 << 1) +#define		AT91_SCKC_OSC32BYP	(1 << 2) +#define		AT91_SCKC_OSCSEL	(1 << 3) + +struct clk_slow_osc { +	struct clk_hw hw; +	void __iomem *sckcr; +	unsigned long startup_usec; +}; + +#define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw) + +struct clk_slow_rc_osc { +	struct clk_hw hw; +	void __iomem *sckcr; +	unsigned long frequency; +	unsigned long accuracy; +	unsigned long startup_usec; +}; + +#define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw) + +struct clk_sam9260_slow { +	struct clk_hw hw; +	struct at91_pmc *pmc; +}; + +#define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw) + +struct clk_sam9x5_slow { +	struct clk_hw hw; +	void __iomem *sckcr; +	u8 parent; +}; + +#define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw) + + +static int clk_slow_osc_prepare(struct clk_hw *hw) +{ +	struct clk_slow_osc *osc = to_clk_slow_osc(hw); +	void __iomem *sckcr = osc->sckcr; +	u32 tmp = readl(sckcr); + +	if (tmp & AT91_SCKC_OSC32BYP) +		return 0; + +	writel(tmp | AT91_SCKC_OSC32EN, sckcr); + +	usleep_range(osc->startup_usec, osc->startup_usec + 1); + +	return 0; +} + +static void clk_slow_osc_unprepare(struct clk_hw *hw) +{ +	struct clk_slow_osc *osc = to_clk_slow_osc(hw); +	void __iomem *sckcr = osc->sckcr; +	u32 tmp = readl(sckcr); + +	if (tmp & AT91_SCKC_OSC32BYP) +		return; + +	writel(tmp & ~AT91_SCKC_OSC32EN, sckcr); +} + +static int clk_slow_osc_is_prepared(struct clk_hw *hw) +{ +	struct clk_slow_osc *osc = to_clk_slow_osc(hw); +	void __iomem *sckcr = osc->sckcr; +	u32 tmp = readl(sckcr); + +	if (tmp & AT91_SCKC_OSC32BYP) +		return 1; + +	return !!(tmp & AT91_SCKC_OSC32EN); +} + +static const struct clk_ops slow_osc_ops = { +	.prepare = clk_slow_osc_prepare, +	.unprepare = clk_slow_osc_unprepare, +	.is_prepared = clk_slow_osc_is_prepared, +}; + +static struct clk * __init +at91_clk_register_slow_osc(void __iomem *sckcr, +			   const char *name, +			   const char *parent_name, +			   unsigned long startup, +			   bool bypass) +{ +	struct clk_slow_osc *osc; +	struct clk *clk = NULL; +	struct clk_init_data init; + +	if (!sckcr || !name || !parent_name) +		return ERR_PTR(-EINVAL); + +	osc = kzalloc(sizeof(*osc), GFP_KERNEL); +	if (!osc) +		return ERR_PTR(-ENOMEM); + +	init.name = name; +	init.ops = &slow_osc_ops; +	init.parent_names = &parent_name; +	init.num_parents = 1; +	init.flags = CLK_IGNORE_UNUSED; + +	osc->hw.init = &init; +	osc->sckcr = sckcr; +	osc->startup_usec = startup; + +	if (bypass) +		writel((readl(sckcr) & ~AT91_SCKC_OSC32EN) | AT91_SCKC_OSC32BYP, +		       sckcr); + +	clk = clk_register(NULL, &osc->hw); +	if (IS_ERR(clk)) +		kfree(osc); + +	return clk; +} + +void __init of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, +					     void __iomem *sckcr) +{ +	struct clk *clk; +	const char *parent_name; +	const char *name = np->name; +	u32 startup; +	bool bypass; + +	parent_name = of_clk_get_parent_name(np, 0); +	of_property_read_string(np, "clock-output-names", &name); +	of_property_read_u32(np, "atmel,startup-time-usec", &startup); +	bypass = of_property_read_bool(np, "atmel,osc-bypass"); + +	clk = at91_clk_register_slow_osc(sckcr, name, parent_name, startup, +					 bypass); +	if (IS_ERR(clk)) +		return; + +	of_clk_add_provider(np, of_clk_src_simple_get, clk); +} + +static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw *hw, +						 unsigned long parent_rate) +{ +	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw); + +	return osc->frequency; +} + +static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw *hw, +						     unsigned long parent_acc) +{ +	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw); + +	return osc->accuracy; +} + +static int clk_slow_rc_osc_prepare(struct clk_hw *hw) +{ +	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw); +	void __iomem *sckcr = osc->sckcr; + +	writel(readl(sckcr) | AT91_SCKC_RCEN, sckcr); + +	usleep_range(osc->startup_usec, osc->startup_usec + 1); + +	return 0; +} + +static void clk_slow_rc_osc_unprepare(struct clk_hw *hw) +{ +	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw); +	void __iomem *sckcr = osc->sckcr; + +	writel(readl(sckcr) & ~AT91_SCKC_RCEN, sckcr); +} + +static int clk_slow_rc_osc_is_prepared(struct clk_hw *hw) +{ +	struct clk_slow_rc_osc *osc = to_clk_slow_rc_osc(hw); + +	return !!(readl(osc->sckcr) & AT91_SCKC_RCEN); +} + +static const struct clk_ops slow_rc_osc_ops = { +	.prepare = clk_slow_rc_osc_prepare, +	.unprepare = clk_slow_rc_osc_unprepare, +	.is_prepared = clk_slow_rc_osc_is_prepared, +	.recalc_rate = clk_slow_rc_osc_recalc_rate, +	.recalc_accuracy = clk_slow_rc_osc_recalc_accuracy, +}; + +static struct clk * __init +at91_clk_register_slow_rc_osc(void __iomem *sckcr, +			      const char *name, +			      unsigned long frequency, +			      unsigned long accuracy, +			      unsigned long startup) +{ +	struct clk_slow_rc_osc *osc; +	struct clk *clk = NULL; +	struct clk_init_data init; + +	if (!sckcr || !name) +		return ERR_PTR(-EINVAL); + +	osc = kzalloc(sizeof(*osc), GFP_KERNEL); +	if (!osc) +		return ERR_PTR(-ENOMEM); + +	init.name = name; +	init.ops = &slow_rc_osc_ops; +	init.parent_names = NULL; +	init.num_parents = 0; +	init.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED; + +	osc->hw.init = &init; +	osc->sckcr = sckcr; +	osc->frequency = frequency; +	osc->accuracy = accuracy; +	osc->startup_usec = startup; + +	clk = clk_register(NULL, &osc->hw); +	if (IS_ERR(clk)) +		kfree(osc); + +	return clk; +} + +void __init of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, +						void __iomem *sckcr) +{ +	struct clk *clk; +	u32 frequency = 0; +	u32 accuracy = 0; +	u32 startup = 0; +	const char *name = np->name; + +	of_property_read_string(np, "clock-output-names", &name); +	of_property_read_u32(np, "clock-frequency", &frequency); +	of_property_read_u32(np, "clock-accuracy", &accuracy); +	of_property_read_u32(np, "atmel,startup-time-usec", &startup); + +	clk = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy, +					    startup); +	if (IS_ERR(clk)) +		return; + +	of_clk_add_provider(np, of_clk_src_simple_get, clk); +} + +static int clk_sam9x5_slow_set_parent(struct clk_hw *hw, u8 index) +{ +	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw); +	void __iomem *sckcr = slowck->sckcr; +	u32 tmp; + +	if (index > 1) +		return -EINVAL; + +	tmp = readl(sckcr); + +	if ((!index && !(tmp & AT91_SCKC_OSCSEL)) || +	    (index && (tmp & AT91_SCKC_OSCSEL))) +		return 0; + +	if (index) +		tmp |= AT91_SCKC_OSCSEL; +	else +		tmp &= ~AT91_SCKC_OSCSEL; + +	writel(tmp, sckcr); + +	usleep_range(SLOWCK_SW_TIME_USEC, SLOWCK_SW_TIME_USEC + 1); + +	return 0; +} + +static u8 clk_sam9x5_slow_get_parent(struct clk_hw *hw) +{ +	struct clk_sam9x5_slow *slowck = to_clk_sam9x5_slow(hw); + +	return !!(readl(slowck->sckcr) & AT91_SCKC_OSCSEL); +} + +static const struct clk_ops sam9x5_slow_ops = { +	.set_parent = clk_sam9x5_slow_set_parent, +	.get_parent = clk_sam9x5_slow_get_parent, +}; + +static struct clk * __init +at91_clk_register_sam9x5_slow(void __iomem *sckcr, +			      const char *name, +			      const char **parent_names, +			      int num_parents) +{ +	struct clk_sam9x5_slow *slowck; +	struct clk *clk = NULL; +	struct clk_init_data init; + +	if (!sckcr || !name || !parent_names || !num_parents) +		return ERR_PTR(-EINVAL); + +	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL); +	if (!slowck) +		return ERR_PTR(-ENOMEM); + +	init.name = name; +	init.ops = &sam9x5_slow_ops; +	init.parent_names = parent_names; +	init.num_parents = num_parents; +	init.flags = 0; + +	slowck->hw.init = &init; +	slowck->sckcr = sckcr; +	slowck->parent = !!(readl(sckcr) & AT91_SCKC_OSCSEL); + +	clk = clk_register(NULL, &slowck->hw); +	if (IS_ERR(clk)) +		kfree(slowck); + +	return clk; +} + +void __init of_at91sam9x5_clk_slow_setup(struct device_node *np, +					 void __iomem *sckcr) +{ +	struct clk *clk; +	const char *parent_names[2]; +	int num_parents; +	const char *name = np->name; +	int i; + +	num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); +	if (num_parents <= 0 || num_parents > 2) +		return; + +	for (i = 0; i < num_parents; ++i) { +		parent_names[i] = of_clk_get_parent_name(np, i); +		if (!parent_names[i]) +			return; +	} + +	of_property_read_string(np, "clock-output-names", &name); + +	clk = at91_clk_register_sam9x5_slow(sckcr, name, parent_names, +					    num_parents); +	if (IS_ERR(clk)) +		return; + +	of_clk_add_provider(np, of_clk_src_simple_get, clk); +} + +static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw) +{ +	struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw); + +	return !!(pmc_read(slowck->pmc, AT91_PMC_SR) & AT91_PMC_OSCSEL); +} + +static const struct clk_ops sam9260_slow_ops = { +	.get_parent = clk_sam9260_slow_get_parent, +}; + +static struct clk * __init +at91_clk_register_sam9260_slow(struct at91_pmc *pmc, +			       const char *name, +			       const char **parent_names, +			       int num_parents) +{ +	struct clk_sam9260_slow *slowck; +	struct clk *clk = NULL; +	struct clk_init_data init; + +	if (!pmc || !name) +		return ERR_PTR(-EINVAL); + +	if (!parent_names || !num_parents) +		return ERR_PTR(-EINVAL); + +	slowck = kzalloc(sizeof(*slowck), GFP_KERNEL); +	if (!slowck) +		return ERR_PTR(-ENOMEM); + +	init.name = name; +	init.ops = &sam9260_slow_ops; +	init.parent_names = parent_names; +	init.num_parents = num_parents; +	init.flags = 0; + +	slowck->hw.init = &init; +	slowck->pmc = pmc; + +	clk = clk_register(NULL, &slowck->hw); +	if (IS_ERR(clk)) +		kfree(slowck); + +	return clk; +} + +void __init of_at91sam9260_clk_slow_setup(struct device_node *np, +					  struct at91_pmc *pmc) +{ +	struct clk *clk; +	const char *parent_names[2]; +	int num_parents; +	const char *name = np->name; +	int i; + +	num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); +	if (num_parents <= 0 || num_parents > 1) +		return; + +	for (i = 0; i < num_parents; ++i) { +		parent_names[i] = of_clk_get_parent_name(np, i); +		if (!parent_names[i]) +			return; +	} + +	of_property_read_string(np, "clock-output-names", &name); + +	clk = at91_clk_register_sam9260_slow(pmc, name, parent_names, +					     num_parents); +	if (IS_ERR(clk)) +		return; + +	of_clk_add_provider(np, of_clk_src_simple_get, clk); +}  | 
