Add a helper comparing two "struct of_phandle_args" to avoid reinventing the wheel.

Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org

---

Dependency of cpufreq and reset change. --- include/linux/of.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)

diff --git a/include/linux/of.h b/include/linux/of.h index 6a9ddf20e79a..85bcc05b278d 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -1065,6 +1065,22 @@ static inline int of_parse_phandle_with_optional_args(const struct device_node * 0, index, out_args); }

+/** + * of_phandle_args_equal() - Compare two of_phandle_args + * @a1: First of_phandle_args to compare + * @a2: Second of_phandle_args to compare + * + * Return: True if a1 and a2 are the same (same node pointer, same phandle + * args), false otherwise. + */ +static inline bool of_phandle_args_equal(const struct of_phandle_args *a1, + const struct of_phandle_args *a2) +{ + return a1->np == a2->np && + a1->args_count == a2->args_count && + !memcmp(a1->args, a2->args, sizeof(a1->args[0]) * a1->args_count); +} + /** * of_property_count_u8_elems - Count the number of u8 elements in a property *

Use newly added of_phandle_args_equal() helper to compare two of_phandle_args.

Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org

---

Depends on previous of change. --- include/linux/cpufreq.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index afda5f24d3dd..3cd06dafb04b 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1149,8 +1149,7 @@ static inline int of_perf_domain_get_sharing_cpumask(int pcpu, const char *list_ if (ret < 0) continue;

- if (pargs->np == args.np && pargs->args_count == args.args_count && - !memcmp(pargs->args, args.args, sizeof(args.args[0]) * args.args_count)) + if (of_phandle_args_equal(pargs, &args)) cpumask_set_cpu(cpu, cpumask);

of_node_put(args.np);

Devices sharing a reset GPIO could use the reset framework for coordinated handling of that shared GPIO line. We have several cases of such needs, at least for Devicetree-based platforms.

If Devicetree-based device requests a reset line, while "resets" Devicetree property is missing but there is a "reset-gpios" one, instantiate a new "reset-gpio" platform device which will handle such reset line. This allows seamless handling of such shared reset-gpios without need of changing Devicetree binding [1].

To avoid creating multiple "reset-gpio" platform devices, store the Devicetree "reset-gpios" GPIO specifiers used for new devices on a linked list. Later such Devicetree GPIO specifier (phandle to GPIO controller, GPIO number and GPIO flags) is used to check if reset controller for given GPIO was already registered.

If two devices have conflicting "reset-gpios" property, e.g. with different ACTIVE_xxx flags, this would allow to spawn two separate "reset-gpio" devices, where the second would fail probing on busy GPIO request.

Link: https://lore.kernel.org/all/YXi5CUCEi7YmNxXM@robh.at.kernel.org/ [1] Cc: Bartosz Golaszewski brgl@bgdev.pl Cc: Chris Packham chris.packham@alliedtelesis.co.nz Cc: Sean Anderson sean.anderson@seco.com Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org

---

Depends on previous of change. --- drivers/reset/core.c | 213 +++++++++++++++++++++++++++++-- include/linux/reset-controller.h | 4 + 2 files changed, 204 insertions(+), 13 deletions(-)

diff --git a/drivers/reset/core.c b/drivers/reset/core.c index 4d5a78d3c085..6e81b8d35055 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -10,9 +10,13 @@ #include <linux/export.h> #include <linux/kernel.h> #include <linux/kref.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/machine.h> +#include <linux/idr.h> #include <linux/module.h> #include <linux/of.h> #include <linux/acpi.h> +#include <linux/platform_device.h> #include <linux/reset.h> #include <linux/reset-controller.h> #include <linux/slab.h> @@ -23,6 +27,11 @@ static LIST_HEAD(reset_controller_list); static DEFINE_MUTEX(reset_lookup_mutex); static LIST_HEAD(reset_lookup_list);

+/* Protects reset_gpio_lookup_list */ +static DEFINE_MUTEX(reset_gpio_lookup_mutex); +static LIST_HEAD(reset_gpio_lookup_list); +static DEFINE_IDA(reset_gpio_ida); + /** * struct reset_control - a reset control * @rcdev: a pointer to the reset controller device @@ -63,6 +72,16 @@ struct reset_control_array { struct reset_control *rstc[] __counted_by(num_rstcs); };

+/** + * struct reset_gpio_lookup - lookup key for ad-hoc created reset-gpio devices + * @of_args: phandle to the reset controller with all the args like GPIO number + * @list: list entry for the reset_gpio_lookup_list + */ +struct reset_gpio_lookup { + struct of_phandle_args of_args; + struct list_head list; +}; + static const char *rcdev_name(struct reset_controller_dev *rcdev) { if (rcdev->dev) @@ -71,6 +90,9 @@ static const char *rcdev_name(struct reset_controller_dev *rcdev) if (rcdev->of_node) return rcdev->of_node->full_name;

+ if (rcdev->of_args) + return rcdev->of_args->np->full_name; + return NULL; }

@@ -99,6 +121,9 @@ static int of_reset_simple_xlate(struct reset_controller_dev *rcdev, */ int reset_controller_register(struct reset_controller_dev *rcdev) { + if (rcdev->of_node && rcdev->of_args) + return -EINVAL; + if (!rcdev->of_xlate) { rcdev->of_reset_n_cells = 1; rcdev->of_xlate = of_reset_simple_xlate; @@ -813,12 +838,161 @@ static void __reset_control_put_internal(struct reset_control *rstc) kref_put(&rstc->refcnt, __reset_control_release); }

+static int __reset_add_reset_gpio_lookup(int id, struct device_node *np, + unsigned int gpio, + unsigned int of_flags) +{ + unsigned int lookup_flags; + const char *label_tmp; + + /* + * Later we map GPIO flags between OF and Linux, however not all + * constants from include/dt-bindings/gpio/gpio.h and + * include/linux/gpio/machine.h match each other. + */ + if (of_flags > GPIO_ACTIVE_LOW) { + pr_err("reset-gpio code does not support GPIO flags %u for GPIO %u\n", + of_flags, gpio); + return -EINVAL; + } + + struct gpio_device *gdev __free(gpio_device_put) = gpio_device_find_by_fwnode(of_fwnode_handle(np)); + if (!gdev) + return -EPROBE_DEFER; + + label_tmp = gpio_device_get_label(gdev); + if (!label_tmp) + return -EINVAL; + + char *label __free(kfree) = kstrdup(label_tmp, GFP_KERNEL); + if (!label) + return -ENOMEM; + + /* Size: one lookup entry plus sentinel */ + struct gpiod_lookup_table *lookup __free(kfree) = kzalloc(struct_size(lookup, table, 2), + GFP_KERNEL); + if (!lookup) + return -ENOMEM; + + lookup->dev_id = kasprintf(GFP_KERNEL, "reset-gpio.%d", id); + if (!lookup->dev_id) + return -ENOMEM; + + lookup_flags = GPIO_PERSISTENT; + lookup_flags |= of_flags & GPIO_ACTIVE_LOW; + lookup->table[0] = GPIO_LOOKUP(no_free_ptr(label), gpio, "reset", + lookup_flags); + + /* Not freed on success, because it is persisent subsystem data. */ + gpiod_add_lookup_table(no_free_ptr(lookup)); + + return 0; +} + +/* + * @args: phandle to the GPIO provider with all the args like GPIO number + */ +static int __reset_add_reset_gpio_device(const struct of_phandle_args *args) +{ + struct reset_gpio_lookup *rgpio_dev; + struct platform_device *pdev; + int id, ret; + + /* + * Registering reset-gpio device might cause immediate + * bind, resulting in its probe() registering new reset controller thus + * taking reset_list_mutex lock via reset_controller_register(). + */ + lockdep_assert_not_held(&reset_list_mutex); + + mutex_lock(&reset_gpio_lookup_mutex); + + list_for_each_entry(rgpio_dev, &reset_gpio_lookup_list, list) { + if (args->np == rgpio_dev->of_args.np) { + if (of_phandle_args_equal(args, &rgpio_dev->of_args)) + goto out; /* Already on the list, done */ + } + } + + id = ida_alloc(&reset_gpio_ida, GFP_KERNEL); + if (id < 0) { + ret = id; + goto err_unlock; + } + + /* Not freed on success, because it is persisent subsystem data. */ + rgpio_dev = kzalloc(sizeof(*rgpio_dev), GFP_KERNEL); + if (!rgpio_dev) { + ret = -ENOMEM; + goto err_ida_free; + } + + ret = __reset_add_reset_gpio_lookup(id, args->np, args->args[0], + args->args[1]); + if (ret < 0) + goto err_kfree; + + rgpio_dev->of_args = *args; + /* + * We keep the device_node reference, but of_args.np is put at the end + * of __of_reset_control_get(), so get it one more time. + * Hold reference as long as rgpio_dev memory is valid. + */ + of_node_get(rgpio_dev->of_args.np); + pdev = platform_device_register_data(NULL, "reset-gpio", id, + &rgpio_dev->of_args, + sizeof(rgpio_dev->of_args)); + ret = PTR_ERR_OR_ZERO(pdev); + if (ret) + goto err_put; + + list_add(&rgpio_dev->list, &reset_gpio_lookup_list); + +out: + mutex_unlock(&reset_gpio_lookup_mutex); + + return 0; + +err_put: + of_node_put(rgpio_dev->of_args.np); +err_kfree: + kfree(rgpio_dev); +err_ida_free: + ida_free(&reset_gpio_ida, id); +err_unlock: + mutex_unlock(&reset_gpio_lookup_mutex); + + return ret; +} + +static struct reset_controller_dev *__reset_find_rcdev(const struct of_phandle_args *args, + bool gpio_fallback) +{ + struct reset_controller_dev *rcdev; + + lockdep_assert_held(&reset_list_mutex); + + list_for_each_entry(rcdev, &reset_controller_list, list) { + if (gpio_fallback) { + if (rcdev->of_args && of_phandle_args_equal(args, + rcdev->of_args)) + return rcdev; + } else { + if (args->np == rcdev->of_node) + return rcdev; + } + } + + return NULL; +} + struct reset_control * __of_reset_control_get(struct device_node *node, const char *id, int index, bool shared, bool optional, bool acquired) { + bool gpio_fallback = false; struct reset_control *rstc; - struct reset_controller_dev *r, *rcdev; + struct reset_controller_dev *rcdev; struct of_phandle_args args; int rstc_id; int ret; @@ -839,39 +1013,52 @@ __of_reset_control_get(struct device_node *node, const char *id, int index, index, &args); if (ret == -EINVAL) return ERR_PTR(ret); - if (ret) - return optional ? NULL : ERR_PTR(ret); + if (ret) { + if (!IS_ENABLED(CONFIG_RESET_GPIO)) + return optional ? NULL : ERR_PTR(ret);

- mutex_lock(&reset_list_mutex); - rcdev = NULL; - list_for_each_entry(r, &reset_controller_list, list) { - if (args.np == r->of_node) { - rcdev = r; - break; + /* + * There can be only one reset-gpio for regular devices, so + * don't bother with the "reset-gpios" phandle index. + */ + ret = of_parse_phandle_with_args(node, "reset-gpios", "#gpio-cells", + 0, &args); + if (ret) + return optional ? NULL : ERR_PTR(ret); + + gpio_fallback = true; + + ret = __reset_add_reset_gpio_device(&args); + if (ret) { + rstc = ERR_PTR(ret); + goto out_put; } }

+ mutex_lock(&reset_list_mutex); + rcdev = __reset_find_rcdev(&args, gpio_fallback); if (!rcdev) { rstc = ERR_PTR(-EPROBE_DEFER); - goto out; + goto out_unlock; }

if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) { rstc = ERR_PTR(-EINVAL); - goto out; + goto out_unlock; }

rstc_id = rcdev->of_xlate(rcdev, &args); if (rstc_id < 0) { rstc = ERR_PTR(rstc_id); - goto out; + goto out_unlock; }

/* reset_list_mutex also protects the rcdev's reset_control list */ rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);

-out: +out_unlock: mutex_unlock(&reset_list_mutex); +out_put: of_node_put(args.np);

return rstc; diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h index 0fa4f60e1186..357df16ede32 100644 --- a/include/linux/reset-controller.h +++ b/include/linux/reset-controller.h @@ -60,6 +60,9 @@ struct reset_control_lookup { * @reset_control_head: head of internal list of requested reset controls * @dev: corresponding driver model device struct * @of_node: corresponding device tree node as phandle target + * @of_args: for reset-gpios controllers: corresponding phandle args with + * of_node and GPIO number complementing of_node; either this or + * of_node should be present * @of_reset_n_cells: number of cells in reset line specifiers * @of_xlate: translation function to translate from specifier as found in the * device tree to id as given to the reset control ops, defaults @@ -73,6 +76,7 @@ struct reset_controller_dev { struct list_head reset_control_head; struct device *dev; struct device_node *of_node; + const struct of_phandle_args *of_args; int of_reset_n_cells; int (*of_xlate)(struct reset_controller_dev *rcdev, const struct of_phandle_args *reset_spec);

On some boards with multiple WSA8840/WSA8845 speakers, the reset (shutdown) GPIO is shared between two speakers. Use the reset controller framework and its "reset-gpio" driver to handle this case. This allows bring-up and proper handling of all WSA884x speakers on X1E80100-CRD board.

Cc: Bartosz Golaszewski brgl@bgdev.pl Cc: Sean Anderson sean.anderson@seco.com Signed-off-by: Krzysztof Kozlowski krzysztof.kozlowski@linaro.org

---

If previous patches are fine, then this commit is independent and could be taken via ASoC. --- sound/soc/codecs/wsa884x.c | 53 +++++++++++++++++++++++++++++++------- 1 file changed, 43 insertions(+), 10 deletions(-)

diff --git a/sound/soc/codecs/wsa884x.c b/sound/soc/codecs/wsa884x.c index f2653df84e4a..a9767ef0e39d 100644 --- a/sound/soc/codecs/wsa884x.c +++ b/sound/soc/codecs/wsa884x.c @@ -13,6 +13,7 @@ #include <linux/pm_runtime.h> #include <linux/regmap.h> #include <linux/regulator/consumer.h> +#include <linux/reset.h> #include <linux/slab.h> #include <linux/soundwire/sdw.h> #include <linux/soundwire/sdw_registers.h> @@ -699,6 +700,7 @@ struct wsa884x_priv { struct sdw_stream_runtime *sruntime; struct sdw_port_config port_config[WSA884X_MAX_SWR_PORTS]; struct gpio_desc *sd_n; + struct reset_control *sd_reset; bool port_prepared[WSA884X_MAX_SWR_PORTS]; bool port_enable[WSA884X_MAX_SWR_PORTS]; unsigned int variant; @@ -1799,9 +1801,22 @@ static struct snd_soc_dai_driver wsa884x_dais[] = { }, };

-static void wsa884x_gpio_powerdown(void *data) +static void wsa884x_reset_powerdown(void *data) { - gpiod_direction_output(data, 1); + struct wsa884x_priv *wsa884x = data; + + if (wsa884x->sd_reset) + reset_control_assert(wsa884x->sd_reset); + else + gpiod_direction_output(wsa884x->sd_n, 1); +} + +static void wsa884x_reset_deassert(struct wsa884x_priv *wsa884x) +{ + if (wsa884x->sd_reset) + reset_control_deassert(wsa884x->sd_reset); + else + gpiod_direction_output(wsa884x->sd_n, 0); }

static void wsa884x_regulator_disable(void *data) @@ -1809,6 +1824,27 @@ static void wsa884x_regulator_disable(void *data) regulator_bulk_disable(WSA884X_SUPPLIES_NUM, data); }

+static int wsa884x_get_reset(struct device *dev, struct wsa884x_priv *wsa884x) +{ + wsa884x->sd_reset = devm_reset_control_get_optional_shared(dev, NULL); + if (IS_ERR(wsa884x->sd_reset)) + return dev_err_probe(dev, PTR_ERR(wsa884x->sd_reset), + "Failed to get reset\n"); + else if (wsa884x->sd_reset) + return 0; + /* + * else: NULL, so use the backwards compatible way for powerdown-gpios, + * which does not handle sharing GPIO properly. + */ + wsa884x->sd_n = devm_gpiod_get_optional(dev, "powerdown", + GPIOD_OUT_HIGH); + if (IS_ERR(wsa884x->sd_n)) + return dev_err_probe(dev, PTR_ERR(wsa884x->sd_n), + "Shutdown Control GPIO not found\n"); + + return 0; +} + static int wsa884x_probe(struct sdw_slave *pdev, const struct sdw_device_id *id) { @@ -1838,11 +1874,9 @@ static int wsa884x_probe(struct sdw_slave *pdev, if (ret) return ret;

- wsa884x->sd_n = devm_gpiod_get_optional(dev, "powerdown", - GPIOD_OUT_HIGH); - if (IS_ERR(wsa884x->sd_n)) - return dev_err_probe(dev, PTR_ERR(wsa884x->sd_n), - "Shutdown Control GPIO not found\n"); + ret = wsa884x_get_reset(dev, wsa884x); + if (ret) + return ret;

dev_set_drvdata(dev, wsa884x); wsa884x->slave = pdev; @@ -1858,9 +1892,8 @@ static int wsa884x_probe(struct sdw_slave *pdev, pdev->prop.sink_dpn_prop = wsa884x_sink_dpn_prop; pdev->prop.scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY;

- /* Bring out of reset */ - gpiod_direction_output(wsa884x->sd_n, 0); - ret = devm_add_action_or_reset(dev, wsa884x_gpio_powerdown, wsa884x->sd_n); + wsa884x_reset_deassert(wsa884x); + ret = devm_add_action_or_reset(dev, wsa884x_reset_powerdown, wsa884x); if (ret) return ret;