Messages in this thread Patch in this message | | | Subject | Re: [PATCH 02/11] mux: core: Add support for getting a mux controller on a non DT platform | From | Hans de Goede <> | Date | Tue, 5 Sep 2017 12:58:12 +0200 |
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Hi,
On 04-09-17 13:19, Peter Rosin wrote: > Hi! > > Some comments inline... > > On 2017-09-01 23:48, Hans de Goede wrote: >> On non DT platforms we cannot get the mux_chip by pnode. Other subsystems >> (regulator, clock, pwm) have the same problem and solve this by allowing >> platform / board-setup code to add entries to a lookup table and then use >> this table to look things up. >> >> This commit adds support for getting a mux controller on a non DT platform >> following this pattern. It is based on a simplified version of the pwm >> subsys lookup code, the dev_id and mux_name parts of a lookup table entry >> are mandatory in the mux-core implementation. >> >> Signed-off-by: Hans de Goede <hdegoede@redhat.com> >> --- >> drivers/mux/core.c | 96 +++++++++++++++++++++++++++++++++++++++++++- >> include/linux/mux/consumer.h | 11 +++++ >> 2 files changed, 106 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/mux/core.c b/drivers/mux/core.c >> index 6142493c327b..8864cc745506 100644 >> --- a/drivers/mux/core.c >> +++ b/drivers/mux/core.c >> @@ -24,6 +24,9 @@ >> #include <linux/of_platform.h> >> #include <linux/slab.h> >> >> +static DEFINE_MUTEX(mux_lookup_lock); >> +static LIST_HEAD(mux_lookup_list); >> + >> /* >> * The idle-as-is "state" is not an actual state that may be selected, it >> * only implies that the state should not be changed. So, use that state >> @@ -408,6 +411,23 @@ int mux_control_deselect(struct mux_control *mux) >> } >> EXPORT_SYMBOL_GPL(mux_control_deselect); >> >> +static int parent_name_match(struct device *dev, const void *data) >> +{ >> + const char *parent_name = dev_name(dev->parent); >> + const char *name = data; >> + >> + return strcmp(parent_name, name) == 0; >> +} >> + >> +static struct mux_chip *mux_chip_get_by_name(const char *name) >> +{ >> + struct device *dev; >> + >> + dev = class_find_device(&mux_class, NULL, name, parent_name_match); >> + >> + return dev ? to_mux_chip(dev) : NULL; >> +} >> + >> static int of_dev_node_match(struct device *dev, const void *data) >> { >> return dev->of_node == data; >> @@ -479,6 +499,42 @@ static struct mux_control *of_mux_control_get(struct device *dev, >> } >> >> /** >> + * mux_add_table() - register PWM device consumers > > register mux controllers (because you are not registering consumers, right? > someone is registering controllers so that they can be found by consumers?)
Actually what is being registered is a "consumer to mux-controller mapping", I will update the kernel-doc comments to use that everywhere.
> >> + * @table: array of consumers to register >> + * @num: number of consumers in table > > controllers?
mappings :)
>> + */ >> +void mux_add_table(struct mux_lookup *table, size_t num) >> +{ >> + mutex_lock(&mux_lookup_lock); >> + >> + while (num--) { >> + list_add_tail(&table->list, &mux_lookup_list); >> + table++; >> + } > > I prefer > > for (; num--; table++) > list_add_tail(&table->list, &mux_lookup_list);
Sure, works for me.
>> + >> + mutex_unlock(&mux_lookup_lock); >> +} >> +EXPORT_SYMBOL_GPL(mux_add_table); >> + >> +/** >> + * mux_remove_table() - unregister PWM device consumers > > unregister mux controllers(?) > >> + * @table: array of consumers to unregister >> + * @num: number of consumers in table > > controllers? > >> + */ >> +void mux_remove_table(struct mux_lookup *table, size_t num) >> +{ >> + mutex_lock(&mux_lookup_lock); >> + >> + while (num--) { >> + list_del(&table->list); >> + table++; >> + } > > for() loop here as well.
Ack.
>> + >> + mutex_unlock(&mux_lookup_lock); >> +} >> +EXPORT_SYMBOL_GPL(mux_remove_table); >> + >> +/** >> * mux_control_get() - Get the mux-control for a device. >> * @dev: The device that needs a mux-control. >> * @mux_name: The name identifying the mux-control. >> @@ -487,11 +543,49 @@ static struct mux_control *of_mux_control_get(struct device *dev, >> */ >> struct mux_control *mux_control_get(struct device *dev, const char *mux_name) >> { >> + struct mux_lookup *m, *chosen = NULL; >> + const char *dev_id = dev_name(dev); >> + struct mux_chip *mux_chip; >> + >> /* look up via DT first */ >> if (IS_ENABLED(CONFIG_OF) && dev->of_node) >> return of_mux_control_get(dev, mux_name); >> >> - return ERR_PTR(-ENODEV); >> + /* >> + * For non DT we look up the provider in the static table typically >> + * provided by board setup code. >> + * >> + * If a match is found, the provider mux chip is looked up by name >> + * and a mux-control is requested using the table provided index. >> + */ >> + mutex_lock(&mux_lookup_lock); >> + list_for_each_entry(m, &mux_lookup_list, list) { >> + if (WARN_ON(!m->dev_id || !m->mux_name || !m->provider)) >> + continue; >> + >> + if (strcmp(m->dev_id, dev_id) == 0 && >> + strcmp(m->mux_name, mux_name) == 0) { > > I want the below format (with ! instead of == 0 and the brace on the next line > when the condition has a line break):
Ok, I think checkpatch is going to not like that "{" there, but I'm fine with putting it there.
> if (!strcmp(m->dev_id, dev_id) && > !strcmp(m->mux_name, mux_name)) > { > >> + chosen = m; >> + break; >> + } >> + } >> + mutex_unlock(&mux_lookup_lock); >> + >> + if (!chosen) >> + return ERR_PTR(-ENODEV); >> + >> + mux_chip = mux_chip_get_by_name(chosen->provider); >> + if (!mux_chip) >> + return ERR_PTR(-EPROBE_DEFER); >> + >> + if (chosen->index >= mux_chip->controllers) { >> + dev_err(dev, "Mux lookup table index out of bounds %u >= %u\n", >> + chosen->index, mux_chip->controllers); >> + put_device(&mux_chip->dev); >> + return ERR_PTR(-EINVAL); >> + } >> + >> + return &mux_chip->mux[chosen->index]; >> } >> EXPORT_SYMBOL_GPL(mux_control_get); >> >> diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h >> index ea96d4c82be7..912dd48a3a5d 100644 >> --- a/include/linux/mux/consumer.h >> +++ b/include/linux/mux/consumer.h >> @@ -18,6 +18,17 @@ >> struct device; >> struct mux_control; >> > > I want a kernel-doc comment here, describing the structure.
Ok.
>> +struct mux_lookup { >> + struct list_head list; >> + const char *provider; >> + unsigned int index; >> + const char *dev_id; >> + const char *mux_name; >> +}; >> + >> +void mux_add_table(struct mux_lookup *table, size_t num); >> +void mux_remove_table(struct mux_lookup *table, size_t num); >> + > > I'm not sure if consumer.h is the right place for this, but it can > be moved when I think of something better. Which I can't for the > moment... > >> unsigned int mux_control_states(struct mux_control *mux); >> int __must_check mux_control_select(struct mux_control *mux, >> unsigned int state); >> >
I will address all comments for v2 of series.
Regards,
Hans
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