From 557acb3d2cd9c82de19f944f6cc967a347735385 Mon Sep 17 00:00:00 2001 From: Amjad Ouled-Ameur Date: Fri, 13 Nov 2020 00:00:43 +0100 Subject: reset: make shared pulsed reset controls re-triggerable The current reset framework API does not allow to release what is done by reset_control_reset(), IOW decrement triggered_count. Add the new reset_control_rearm() call to do so. When reset_control_reset() has been called once, the counter triggered_count, in the reset framework, is incremented i.e the resource under the reset is in-use and the reset should not be done again. reset_control_rearm() would be the way to state that the resource is no longer used and, that from the caller's perspective, the reset can be fired again if necessary. Signed-off-by: Amjad Ouled-Ameur Reported-by: Jerome Brunet Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) (limited to 'drivers/reset') diff --git a/drivers/reset/core.c b/drivers/reset/core.c index a2df88e90011..34e89aa0fb5e 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -208,6 +208,39 @@ static int reset_control_array_reset(struct reset_control_array *resets) return 0; } +static int reset_control_array_rearm(struct reset_control_array *resets) +{ + struct reset_control *rstc; + int i; + + for (i = 0; i < resets->num_rstcs; i++) { + rstc = resets->rstc[i]; + + if (!rstc) + continue; + + if (WARN_ON(IS_ERR(rstc))) + return -EINVAL; + + if (rstc->shared) { + if (WARN_ON(atomic_read(&rstc->deassert_count) != 0)) + return -EINVAL; + } else { + if (!rstc->acquired) + return -EPERM; + } + } + + for (i = 0; i < resets->num_rstcs; i++) { + rstc = resets->rstc[i]; + + if (rstc && rstc->shared) + WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0); + } + + return 0; +} + static int reset_control_array_assert(struct reset_control_array *resets) { int ret, i; @@ -325,6 +358,46 @@ int reset_control_reset(struct reset_control *rstc) } EXPORT_SYMBOL_GPL(reset_control_reset); +/** + * reset_control_rearm - allow shared reset line to be re-triggered" + * @rstc: reset controller + * + * On a shared reset line the actual reset pulse is only triggered once for the + * lifetime of the reset_control instance, except if this call is used. + * + * Calls to this function must be balanced with calls to reset_control_reset, + * a warning is thrown in case triggered_count ever dips below 0. + * + * Consumers must not use reset_control_(de)assert on shared reset lines when + * reset_control_reset or reset_control_rearm have been used. + * + * If rstc is NULL the function will just return 0. + */ +int reset_control_rearm(struct reset_control *rstc) +{ + if (!rstc) + return 0; + + if (WARN_ON(IS_ERR(rstc))) + return -EINVAL; + + if (reset_control_is_array(rstc)) + return reset_control_array_rearm(rstc_to_array(rstc)); + + if (rstc->shared) { + if (WARN_ON(atomic_read(&rstc->deassert_count) != 0)) + return -EINVAL; + + WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0); + } else { + if (!rstc->acquired) + return -EPERM; + } + + return 0; +} +EXPORT_SYMBOL_GPL(reset_control_rearm); + /** * reset_control_assert - asserts the reset line * @rstc: reset controller -- cgit v1.2.3 From 3bfe8933f9d187f93f0d0910b741a59070f58c4c Mon Sep 17 00:00:00 2001 From: Neil Armstrong Date: Mon, 19 Oct 2020 16:48:09 +0200 Subject: reset: meson: make it possible to build as a module In order to reduce the kernel Image size on multi-platform distributions, make it possible to build the reset controller driver as a module. This partially reverts commit 8290924e6878 ("reset: meson: make it explicitly non-modular"). Signed-off-by: Neil Armstrong Reviewed-by: Kevin Hilman Tested-by: Kevin Hilman Reviewed-by: Martin Blumenstingl Signed-off-by: Philipp Zabel --- drivers/reset/Kconfig | 3 ++- drivers/reset/reset-meson.c | 8 +++++++- 2 files changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/reset') diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 07d162b179fc..84baec01aa30 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -95,7 +95,8 @@ config RESET_LPC18XX This enables the reset controller driver for NXP LPC18xx/43xx SoCs. config RESET_MESON - bool "Meson Reset Driver" if COMPILE_TEST + tristate "Meson Reset Driver" + depends on ARCH_MESON || COMPILE_TEST default ARCH_MESON help This enables the reset driver for Amlogic Meson SoCs. diff --git a/drivers/reset/reset-meson.c b/drivers/reset/reset-meson.c index 94d7ba88d7d2..c9bc325ad65a 100644 --- a/drivers/reset/reset-meson.c +++ b/drivers/reset/reset-meson.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -104,6 +105,7 @@ static const struct of_device_id meson_reset_dt_ids[] = { { .compatible = "amlogic,meson-a1-reset", .data = &meson_a1_param}, { /* sentinel */ }, }; +MODULE_DEVICE_TABLE(of, meson_reset_dt_ids); static int meson_reset_probe(struct platform_device *pdev) { @@ -142,4 +144,8 @@ static struct platform_driver meson_reset_driver = { .of_match_table = meson_reset_dt_ids, }, }; -builtin_platform_driver(meson_reset_driver); +module_platform_driver(meson_reset_driver); + +MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver"); +MODULE_AUTHOR("Neil Armstrong "); +MODULE_LICENSE("Dual BSD/GPL"); -- cgit v1.2.3 From 0d625a167b169f0bfdfd2e4dc05b9c89b81efe98 Mon Sep 17 00:00:00 2001 From: Dinh Nguyen Date: Mon, 9 Nov 2020 13:21:41 -0600 Subject: reset: socfpga: add error handling and release mem-region In case of an error, call release_mem_region when an error happens during allocation of resources. Also add error handling for the case that reset_controller_register fails. Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Dinh Nguyen Signed-off-by: Philipp Zabel --- drivers/reset/reset-socfpga.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/reset') diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c index bdd984296196..2a72f861f798 100644 --- a/drivers/reset/reset-socfpga.c +++ b/drivers/reset/reset-socfpga.c @@ -44,7 +44,7 @@ static int a10_reset_init(struct device_node *np) data->membase = ioremap(res.start, size); if (!data->membase) { ret = -ENOMEM; - goto err_alloc; + goto release_region; } if (of_property_read_u32(np, "altr,modrst-offset", ®_offset)) @@ -59,7 +59,14 @@ static int a10_reset_init(struct device_node *np) data->rcdev.of_node = np; data->status_active_low = true; - return reset_controller_register(&data->rcdev); + ret = reset_controller_register(&data->rcdev); + if (ret) + pr_err("unable to register device\n"); + + return ret; + +release_region: + release_mem_region(res.start, size); err_alloc: kfree(data); -- cgit v1.2.3 From d06c4dec98b655e2808d2a59681ec24197c59c9d Mon Sep 17 00:00:00 2001 From: Crystal Guo Date: Wed, 30 Sep 2020 10:21:59 +0800 Subject: reset-controller: ti: force the write operation when assert or deassert Force the write operation in case the read already happens to return the correct value. Signed-off-by: Crystal Guo Signed-off-by: Philipp Zabel --- drivers/reset/reset-ti-syscon.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/reset') diff --git a/drivers/reset/reset-ti-syscon.c b/drivers/reset/reset-ti-syscon.c index ef97c4dbbb4e..218370faf37b 100644 --- a/drivers/reset/reset-ti-syscon.c +++ b/drivers/reset/reset-ti-syscon.c @@ -89,7 +89,7 @@ static int ti_syscon_reset_assert(struct reset_controller_dev *rcdev, mask = BIT(control->assert_bit); value = (control->flags & ASSERT_SET) ? mask : 0x0; - return regmap_update_bits(data->regmap, control->assert_offset, mask, value); + return regmap_write_bits(data->regmap, control->assert_offset, mask, value); } /** @@ -120,7 +120,7 @@ static int ti_syscon_reset_deassert(struct reset_controller_dev *rcdev, mask = BIT(control->deassert_bit); value = (control->flags & DEASSERT_SET) ? mask : 0x0; - return regmap_update_bits(data->regmap, control->deassert_offset, mask, value); + return regmap_write_bits(data->regmap, control->deassert_offset, mask, value); } /** -- cgit v1.2.3