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); +} |