| /* |
| * 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/mfd/syscon.h> |
| #include <linux/regmap.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 regmap *regmap; |
| }; |
| |
| #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; |
| |
| 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); |
| |
| 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); |
| unsigned int status; |
| |
| regmap_read(slowck->regmap, AT91_PMC_SR, &status); |
| |
| return status & AT91_PMC_OSCSEL ? 1 : 0; |
| } |
| |
| 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 regmap *regmap, |
| 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 (!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->regmap = regmap; |
| |
| clk = clk_register(NULL, &slowck->hw); |
| if (IS_ERR(clk)) |
| kfree(slowck); |
| |
| return clk; |
| } |
| |
| static void __init of_at91sam9260_clk_slow_setup(struct device_node *np) |
| { |
| struct clk *clk; |
| const char *parent_names[2]; |
| int num_parents; |
| const char *name = np->name; |
| struct regmap *regmap; |
| |
| num_parents = of_clk_get_parent_count(np); |
| if (num_parents != 2) |
| return; |
| |
| of_clk_parent_fill(np, parent_names, num_parents); |
| regmap = syscon_node_to_regmap(of_get_parent(np)); |
| if (IS_ERR(regmap)) |
| return; |
| |
| of_property_read_string(np, "clock-output-names", &name); |
| |
| clk = at91_clk_register_sam9260_slow(regmap, name, parent_names, |
| num_parents); |
| if (IS_ERR(clk)) |
| return; |
| |
| of_clk_add_provider(np, of_clk_src_simple_get, clk); |
| } |
| |
| CLK_OF_DECLARE(at91sam9260_clk_slow, "atmel,at91sam9260-clk-slow", |
| of_at91sam9260_clk_slow_setup); |