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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/at91/sckc.c | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/drivers/clk/at91/sckc.c b/drivers/clk/at91/sckc.c new file mode 100644 index 000000000..43ba2a8b0 --- /dev/null +++ b/drivers/clk/at91/sckc.c @@ -0,0 +1,531 @@ +/* + * drivers/clk/at91/sckc.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/delay.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/io.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_sama5d4_slow_osc { + struct clk_hw hw; + void __iomem *sckcr; + unsigned long startup_usec; + bool prepared; +}; + +#define to_clk_sama5d4_slow_osc(hw) container_of(hw, struct clk_sama5d4_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_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 | AT91_SCKC_OSC32EN)) + return 0; + + writel(tmp | AT91_SCKC_OSC32EN, sckcr); + + if (system_state < SYSTEM_RUNNING) + udelay(osc->startup_usec); + else + 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_hw * __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_hw *hw; + struct clk_init_data init; + int ret; + + 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); + + hw = &osc->hw; + ret = clk_hw_register(NULL, &osc->hw); + if (ret) { + kfree(osc); + hw = ERR_PTR(ret); + } + + return hw; +} + +static void __init +of_at91sam9x5_clk_slow_osc_setup(struct device_node *np, void __iomem *sckcr) +{ + struct clk_hw *hw; + 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"); + + hw = at91_clk_register_slow_osc(sckcr, name, parent_name, startup, + bypass); + if (IS_ERR(hw)) + return; + + of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); +} + +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); + + if (system_state < SYSTEM_RUNNING) + udelay(osc->startup_usec); + else + 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_hw * __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_hw *hw; + struct clk_init_data init; + int ret; + + 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_IGNORE_UNUSED; + + osc->hw.init = &init; + osc->sckcr = sckcr; + osc->frequency = frequency; + osc->accuracy = accuracy; + osc->startup_usec = startup; + + hw = &osc->hw; + ret = clk_hw_register(NULL, &osc->hw); + if (ret) { + kfree(osc); + hw = ERR_PTR(ret); + } + + return hw; +} + +static void __init +of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node *np, void __iomem *sckcr) +{ + struct clk_hw *hw; + 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); + + hw = at91_clk_register_slow_rc_osc(sckcr, name, frequency, accuracy, + startup); + if (IS_ERR(hw)) + return; + + of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); +} + +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); + + if (system_state < SYSTEM_RUNNING) + udelay(SLOWCK_SW_TIME_USEC); + else + 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_hw * __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_hw *hw; + struct clk_init_data init; + int ret; + + 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); + + hw = &slowck->hw; + ret = clk_hw_register(NULL, &slowck->hw); + if (ret) { + kfree(slowck); + hw = ERR_PTR(ret); + } + + return hw; +} + +static void __init +of_at91sam9x5_clk_slow_setup(struct device_node *np, void __iomem *sckcr) +{ + struct clk_hw *hw; + const char *parent_names[2]; + unsigned int num_parents; + const char *name = np->name; + + num_parents = of_clk_get_parent_count(np); + if (num_parents == 0 || num_parents > 2) + return; + + of_clk_parent_fill(np, parent_names, num_parents); + + of_property_read_string(np, "clock-output-names", &name); + + hw = at91_clk_register_sam9x5_slow(sckcr, name, parent_names, + num_parents); + if (IS_ERR(hw)) + return; + + of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); +} + +static const struct of_device_id sckc_clk_ids[] __initconst = { + /* Slow clock */ + { + .compatible = "atmel,at91sam9x5-clk-slow-osc", + .data = of_at91sam9x5_clk_slow_osc_setup, + }, + { + .compatible = "atmel,at91sam9x5-clk-slow-rc-osc", + .data = of_at91sam9x5_clk_slow_rc_osc_setup, + }, + { + .compatible = "atmel,at91sam9x5-clk-slow", + .data = of_at91sam9x5_clk_slow_setup, + }, + { /*sentinel*/ } +}; + +static void __init of_at91sam9x5_sckc_setup(struct device_node *np) +{ + struct device_node *childnp; + void (*clk_setup)(struct device_node *, void __iomem *); + const struct of_device_id *clk_id; + void __iomem *regbase = of_iomap(np, 0); + + if (!regbase) + return; + + for_each_child_of_node(np, childnp) { + clk_id = of_match_node(sckc_clk_ids, childnp); + if (!clk_id) + continue; + clk_setup = clk_id->data; + clk_setup(childnp, regbase); + } +} +CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc", + of_at91sam9x5_sckc_setup); + +static int clk_sama5d4_slow_osc_prepare(struct clk_hw *hw) +{ + struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw); + + if (osc->prepared) + return 0; + + /* + * Assume that if it has already been selected (for example by the + * bootloader), enough time has aready passed. + */ + if ((readl(osc->sckcr) & AT91_SCKC_OSCSEL)) { + osc->prepared = true; + return 0; + } + + if (system_state < SYSTEM_RUNNING) + udelay(osc->startup_usec); + else + usleep_range(osc->startup_usec, osc->startup_usec + 1); + osc->prepared = true; + + return 0; +} + +static int clk_sama5d4_slow_osc_is_prepared(struct clk_hw *hw) +{ + struct clk_sama5d4_slow_osc *osc = to_clk_sama5d4_slow_osc(hw); + + return osc->prepared; +} + +static const struct clk_ops sama5d4_slow_osc_ops = { + .prepare = clk_sama5d4_slow_osc_prepare, + .is_prepared = clk_sama5d4_slow_osc_is_prepared, +}; + +static void __init of_sama5d4_sckc_setup(struct device_node *np) +{ + void __iomem *regbase = of_iomap(np, 0); + struct clk_hw *hw; + struct clk_sama5d4_slow_osc *osc; + struct clk_init_data init; + const char *xtal_name; + const char *parent_names[2] = { "slow_rc_osc", "slow_osc" }; + bool bypass; + int ret; + + if (!regbase) + return; + + hw = clk_hw_register_fixed_rate_with_accuracy(NULL, parent_names[0], + NULL, 0, 32768, + 250000000); + if (IS_ERR(hw)) + return; + + xtal_name = of_clk_get_parent_name(np, 0); + + bypass = of_property_read_bool(np, "atmel,osc-bypass"); + + osc = kzalloc(sizeof(*osc), GFP_KERNEL); + if (!osc) + return; + + init.name = parent_names[1]; + init.ops = &sama5d4_slow_osc_ops; + init.parent_names = &xtal_name; + init.num_parents = 1; + init.flags = CLK_IGNORE_UNUSED; + + osc->hw.init = &init; + osc->sckcr = regbase; + osc->startup_usec = 1200000; + + if (bypass) + writel((readl(regbase) | AT91_SCKC_OSC32BYP), regbase); + + hw = &osc->hw; + ret = clk_hw_register(NULL, &osc->hw); + if (ret) { + kfree(osc); + return; + } + + hw = at91_clk_register_sam9x5_slow(regbase, "slowck", parent_names, 2); + if (IS_ERR(hw)) + return; + + of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw); +} +CLK_OF_DECLARE(sama5d4_clk_sckc, "atmel,sama5d4-sckc", + of_sama5d4_sckc_setup); |