diff options
Diffstat (limited to 'drivers/reset')
| -rw-r--r-- | drivers/reset/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/reset/Makefile | 1 | ||||
| -rw-r--r-- | drivers/reset/core.c | 217 | ||||
| -rw-r--r-- | drivers/reset/reset-lpc18xx.c | 22 | ||||
| -rw-r--r-- | drivers/reset/reset-oxnas.c | 136 |
5 files changed, 273 insertions, 106 deletions
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index df37212a5..0b2733db0 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -12,5 +12,8 @@ menuconfig RESET_CONTROLLER If unsure, say no. +config RESET_OXNAS + bool + source "drivers/reset/sti/Kconfig" source "drivers/reset/hisilicon/Kconfig" diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index a1fc8eda7..f173fc384 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_ARCH_STI) += sti/ obj-$(CONFIG_ARCH_HISI) += hisilicon/ obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o obj-$(CONFIG_ATH79) += reset-ath79.o +obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o diff --git a/drivers/reset/core.c b/drivers/reset/core.c index f15f150b7..72b32bd15 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -8,6 +8,7 @@ * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ +#include <linux/atomic.h> #include <linux/device.h> #include <linux/err.h> #include <linux/export.h> @@ -18,19 +19,27 @@ #include <linux/reset-controller.h> #include <linux/slab.h> -static DEFINE_MUTEX(reset_controller_list_mutex); +static DEFINE_MUTEX(reset_list_mutex); static LIST_HEAD(reset_controller_list); /** * struct reset_control - a reset control * @rcdev: a pointer to the reset controller device * this reset control belongs to + * @list: list entry for the rcdev's reset controller list * @id: ID of the reset controller in the reset * controller device + * @refcnt: Number of gets of this reset_control + * @shared: Is this a shared (1), or an exclusive (0) reset_control? + * @deassert_cnt: Number of times this reset line has been deasserted */ struct reset_control { struct reset_controller_dev *rcdev; + struct list_head list; unsigned int id; + unsigned int refcnt; + int shared; + atomic_t deassert_count; }; /** @@ -62,9 +71,11 @@ int reset_controller_register(struct reset_controller_dev *rcdev) rcdev->of_xlate = of_reset_simple_xlate; } - mutex_lock(&reset_controller_list_mutex); + INIT_LIST_HEAD(&rcdev->reset_control_head); + + mutex_lock(&reset_list_mutex); list_add(&rcdev->list, &reset_controller_list); - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return 0; } @@ -76,18 +87,23 @@ EXPORT_SYMBOL_GPL(reset_controller_register); */ void reset_controller_unregister(struct reset_controller_dev *rcdev) { - mutex_lock(&reset_controller_list_mutex); + mutex_lock(&reset_list_mutex); list_del(&rcdev->list); - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); } EXPORT_SYMBOL_GPL(reset_controller_unregister); /** * reset_control_reset - reset the controlled device * @rstc: reset controller + * + * Calling this on a shared reset controller is an error. */ int reset_control_reset(struct reset_control *rstc) { + if (WARN_ON(rstc->shared)) + return -EINVAL; + if (rstc->rcdev->ops->reset) return rstc->rcdev->ops->reset(rstc->rcdev, rstc->id); @@ -98,26 +114,48 @@ EXPORT_SYMBOL_GPL(reset_control_reset); /** * reset_control_assert - asserts the reset line * @rstc: reset controller + * + * Calling this on an exclusive reset controller guarantees that the reset + * will be asserted. When called on a shared reset controller the line may + * still be deasserted, as long as other users keep it so. + * + * For shared reset controls a driver cannot expect the hw's registers and + * internal state to be reset, but must be prepared for this to happen. */ int reset_control_assert(struct reset_control *rstc) { - if (rstc->rcdev->ops->assert) - return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id); + if (!rstc->rcdev->ops->assert) + return -ENOTSUPP; - return -ENOTSUPP; + if (rstc->shared) { + if (WARN_ON(atomic_read(&rstc->deassert_count) == 0)) + return -EINVAL; + + if (atomic_dec_return(&rstc->deassert_count) != 0) + return 0; + } + + return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id); } EXPORT_SYMBOL_GPL(reset_control_assert); /** * reset_control_deassert - deasserts the reset line * @rstc: reset controller + * + * After calling this function, the reset is guaranteed to be deasserted. */ int reset_control_deassert(struct reset_control *rstc) { - if (rstc->rcdev->ops->deassert) - return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id); + if (!rstc->rcdev->ops->deassert) + return -ENOTSUPP; - return -ENOTSUPP; + if (rstc->shared) { + if (atomic_inc_return(&rstc->deassert_count) != 1) + return 0; + } + + return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id); } EXPORT_SYMBOL_GPL(reset_control_deassert); @@ -136,18 +174,54 @@ int reset_control_status(struct reset_control *rstc) } EXPORT_SYMBOL_GPL(reset_control_status); -/** - * of_reset_control_get_by_index - Lookup and obtain a reference to a reset - * controller by index. - * @node: device to be reset by the controller - * @index: index of the reset controller - * - * This is to be used to perform a list of resets for a device or power domain - * in whatever order. Returns a struct reset_control or IS_ERR() condition - * containing errno. - */ -struct reset_control *of_reset_control_get_by_index(struct device_node *node, - int index) +static struct reset_control *__reset_control_get( + struct reset_controller_dev *rcdev, + unsigned int index, int shared) +{ + struct reset_control *rstc; + + lockdep_assert_held(&reset_list_mutex); + + list_for_each_entry(rstc, &rcdev->reset_control_head, list) { + if (rstc->id == index) { + if (WARN_ON(!rstc->shared || !shared)) + return ERR_PTR(-EBUSY); + + rstc->refcnt++; + return rstc; + } + } + + rstc = kzalloc(sizeof(*rstc), GFP_KERNEL); + if (!rstc) + return ERR_PTR(-ENOMEM); + + try_module_get(rcdev->owner); + + rstc->rcdev = rcdev; + list_add(&rstc->list, &rcdev->reset_control_head); + rstc->id = index; + rstc->refcnt = 1; + rstc->shared = shared; + + return rstc; +} + +static void __reset_control_put(struct reset_control *rstc) +{ + lockdep_assert_held(&reset_list_mutex); + + if (--rstc->refcnt) + return; + + module_put(rstc->rcdev->owner); + + list_del(&rstc->list); + kfree(rstc); +} + +struct reset_control *__of_reset_control_get(struct device_node *node, + const char *id, int index, int shared) { struct reset_control *rstc; struct reset_controller_dev *r, *rcdev; @@ -155,12 +229,22 @@ struct reset_control *of_reset_control_get_by_index(struct device_node *node, int rstc_id; int ret; + if (!node) + return ERR_PTR(-EINVAL); + + if (id) { + index = of_property_match_string(node, + "reset-names", id); + if (index < 0) + return ERR_PTR(-ENOENT); + } + ret = of_parse_phandle_with_args(node, "resets", "#reset-cells", index, &args); if (ret) return ERR_PTR(ret); - mutex_lock(&reset_controller_list_mutex); + mutex_lock(&reset_list_mutex); rcdev = NULL; list_for_each_entry(r, &reset_controller_list, list) { if (args.np == r->of_node) { @@ -171,78 +255,29 @@ struct reset_control *of_reset_control_get_by_index(struct device_node *node, of_node_put(args.np); if (!rcdev) { - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return ERR_PTR(-EPROBE_DEFER); } if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) { - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return ERR_PTR(-EINVAL); } rstc_id = rcdev->of_xlate(rcdev, &args); if (rstc_id < 0) { - mutex_unlock(&reset_controller_list_mutex); + mutex_unlock(&reset_list_mutex); return ERR_PTR(rstc_id); } - try_module_get(rcdev->owner); - mutex_unlock(&reset_controller_list_mutex); - - rstc = kzalloc(sizeof(*rstc), GFP_KERNEL); - if (!rstc) { - module_put(rcdev->owner); - return ERR_PTR(-ENOMEM); - } + /* reset_list_mutex also protects the rcdev's reset_control list */ + rstc = __reset_control_get(rcdev, rstc_id, shared); - rstc->rcdev = rcdev; - rstc->id = rstc_id; + mutex_unlock(&reset_list_mutex); return rstc; } -EXPORT_SYMBOL_GPL(of_reset_control_get_by_index); - -/** - * of_reset_control_get - Lookup and obtain a reference to a reset controller. - * @node: device to be reset by the controller - * @id: reset line name - * - * Returns a struct reset_control or IS_ERR() condition containing errno. - * - * Use of id names is optional. - */ -struct reset_control *of_reset_control_get(struct device_node *node, - const char *id) -{ - int index = 0; - - if (id) { - index = of_property_match_string(node, - "reset-names", id); - if (index < 0) - return ERR_PTR(-ENOENT); - } - return of_reset_control_get_by_index(node, index); -} -EXPORT_SYMBOL_GPL(of_reset_control_get); - -/** - * reset_control_get - Lookup and obtain a reference to a reset controller. - * @dev: device to be reset by the controller - * @id: reset line name - * - * Returns a struct reset_control or IS_ERR() condition containing errno. - * - * Use of id names is optional. - */ -struct reset_control *reset_control_get(struct device *dev, const char *id) -{ - if (!dev) - return ERR_PTR(-EINVAL); - - return of_reset_control_get(dev->of_node, id); -} -EXPORT_SYMBOL_GPL(reset_control_get); +EXPORT_SYMBOL_GPL(__of_reset_control_get); /** * reset_control_put - free the reset controller @@ -254,8 +289,9 @@ void reset_control_put(struct reset_control *rstc) if (IS_ERR(rstc)) return; - module_put(rstc->rcdev->owner); - kfree(rstc); + mutex_lock(&reset_list_mutex); + __reset_control_put(rstc); + mutex_unlock(&reset_list_mutex); } EXPORT_SYMBOL_GPL(reset_control_put); @@ -264,16 +300,8 @@ static void devm_reset_control_release(struct device *dev, void *res) reset_control_put(*(struct reset_control **)res); } -/** - * devm_reset_control_get - resource managed reset_control_get() - * @dev: device to be reset by the controller - * @id: reset line name - * - * Managed reset_control_get(). For reset controllers returned from this - * function, reset_control_put() is called automatically on driver detach. - * See reset_control_get() for more information. - */ -struct reset_control *devm_reset_control_get(struct device *dev, const char *id) +struct reset_control *__devm_reset_control_get(struct device *dev, + const char *id, int index, int shared) { struct reset_control **ptr, *rstc; @@ -282,7 +310,8 @@ struct reset_control *devm_reset_control_get(struct device *dev, const char *id) if (!ptr) return ERR_PTR(-ENOMEM); - rstc = reset_control_get(dev, id); + rstc = __of_reset_control_get(dev ? dev->of_node : NULL, + id, index, shared); if (!IS_ERR(rstc)) { *ptr = rstc; devres_add(dev, ptr); @@ -292,7 +321,7 @@ struct reset_control *devm_reset_control_get(struct device *dev, const char *id) return rstc; } -EXPORT_SYMBOL_GPL(devm_reset_control_get); +EXPORT_SYMBOL_GPL(__devm_reset_control_get); /** * device_reset - find reset controller associated with the device diff --git a/drivers/reset/reset-lpc18xx.c b/drivers/reset/reset-lpc18xx.c index 3b8a4f5a1..54cca0055 100644 --- a/drivers/reset/reset-lpc18xx.c +++ b/drivers/reset/reset-lpc18xx.c @@ -35,6 +35,7 @@ struct lpc18xx_rgu_data { struct reset_controller_dev rcdev; + struct notifier_block restart_nb; struct clk *clk_delay; struct clk *clk_reg; void __iomem *base; @@ -44,12 +45,13 @@ struct lpc18xx_rgu_data { #define to_rgu_data(p) container_of(p, struct lpc18xx_rgu_data, rcdev) -static void __iomem *rgu_base; - -static int lpc18xx_rgu_restart(struct notifier_block *this, unsigned long mode, +static int lpc18xx_rgu_restart(struct notifier_block *nb, unsigned long mode, void *cmd) { - writel(BIT(LPC18XX_RGU_CORE_RST), rgu_base + LPC18XX_RGU_CTRL0); + struct lpc18xx_rgu_data *rc = container_of(nb, struct lpc18xx_rgu_data, + restart_nb); + + writel(BIT(LPC18XX_RGU_CORE_RST), rc->base + LPC18XX_RGU_CTRL0); mdelay(2000); pr_emerg("%s: unable to restart system\n", __func__); @@ -57,11 +59,6 @@ static int lpc18xx_rgu_restart(struct notifier_block *this, unsigned long mode, return NOTIFY_DONE; } -static struct notifier_block lpc18xx_rgu_restart_nb = { - .notifier_call = lpc18xx_rgu_restart, - .priority = 192, -}; - /* * The LPC18xx RGU has mostly self-deasserting resets except for the * two reset lines going to the internal Cortex-M0 cores. @@ -205,8 +202,9 @@ static int lpc18xx_rgu_probe(struct platform_device *pdev) goto dis_clks; } - rgu_base = rc->base; - ret = register_restart_handler(&lpc18xx_rgu_restart_nb); + rc->restart_nb.priority = 192, + rc->restart_nb.notifier_call = lpc18xx_rgu_restart, + ret = register_restart_handler(&rc->restart_nb); if (ret) dev_warn(&pdev->dev, "failed to register restart handler\n"); @@ -225,7 +223,7 @@ static int lpc18xx_rgu_remove(struct platform_device *pdev) struct lpc18xx_rgu_data *rc = platform_get_drvdata(pdev); int ret; - ret = unregister_restart_handler(&lpc18xx_rgu_restart_nb); + ret = unregister_restart_handler(&rc->restart_nb); if (ret) dev_warn(&pdev->dev, "failed to unregister restart handler\n"); diff --git a/drivers/reset/reset-oxnas.c b/drivers/reset/reset-oxnas.c new file mode 100644 index 000000000..c60fb2dac --- /dev/null +++ b/drivers/reset/reset-oxnas.c @@ -0,0 +1,136 @@ +/* + * drivers/reset/reset-oxnas.c + * + * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com> + * Copyright (C) 2014 Ma Haijun <mahaijuns@gmail.com> + * Copyright (C) 2009 Oxford Semiconductor Ltd + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#include <linux/err.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/types.h> +#include <linux/regmap.h> +#include <linux/mfd/syscon.h> + +/* Regmap offsets */ +#define RST_SET_REGOFFSET 0x34 +#define RST_CLR_REGOFFSET 0x38 + +struct oxnas_reset { + struct regmap *regmap; + struct reset_controller_dev rcdev; +}; + +static int oxnas_reset_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct oxnas_reset *data = + container_of(rcdev, struct oxnas_reset, rcdev); + + regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id)); + msleep(50); + regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id)); + + return 0; +} + +static int oxnas_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct oxnas_reset *data = + container_of(rcdev, struct oxnas_reset, rcdev); + + regmap_write(data->regmap, RST_SET_REGOFFSET, BIT(id)); + + return 0; +} + +static int oxnas_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct oxnas_reset *data = + container_of(rcdev, struct oxnas_reset, rcdev); + + regmap_write(data->regmap, RST_CLR_REGOFFSET, BIT(id)); + + return 0; +} + +static const struct reset_control_ops oxnas_reset_ops = { + .reset = oxnas_reset_reset, + .assert = oxnas_reset_assert, + .deassert = oxnas_reset_deassert, +}; + +static const struct of_device_id oxnas_reset_dt_ids[] = { + { .compatible = "oxsemi,ox810se-reset", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, oxnas_reset_dt_ids); + +static int oxnas_reset_probe(struct platform_device *pdev) +{ + struct oxnas_reset *data; + struct device *parent; + + parent = pdev->dev.parent; + if (!parent) { + dev_err(&pdev->dev, "no parent\n"); + return -ENODEV; + } + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->regmap = syscon_node_to_regmap(parent->of_node); + if (IS_ERR(data->regmap)) { + dev_err(&pdev->dev, "failed to get parent regmap\n"); + return PTR_ERR(data->regmap); + } + + platform_set_drvdata(pdev, data); + + data->rcdev.owner = THIS_MODULE; + data->rcdev.nr_resets = 32; + data->rcdev.ops = &oxnas_reset_ops; + data->rcdev.of_node = pdev->dev.of_node; + + return reset_controller_register(&data->rcdev); +} + +static int oxnas_reset_remove(struct platform_device *pdev) +{ + struct oxnas_reset *data = platform_get_drvdata(pdev); + + reset_controller_unregister(&data->rcdev); + + return 0; +} + +static struct platform_driver oxnas_reset_driver = { + .probe = oxnas_reset_probe, + .remove = oxnas_reset_remove, + .driver = { + .name = "oxnas-reset", + .of_match_table = oxnas_reset_dt_ids, + }, +}; + +module_platform_driver(oxnas_reset_driver); |