From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Jonathan Corbet <corbet@lwn.net>,
Harish Jenny K N <harish_kandiga@mentor.com>,
Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: Alexander Graf <graf@amazon.com>,
Peter Maydell <peter.maydell@linaro.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Phil Reid <preid@electromag.com.au>,
Marc Zyngier <marc.zyngier@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Magnus Damm <magnus.damm@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org,
linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
qemu-devel@nongnu.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH v5 2/5] gpiolib: Add support for GPIO line table lookup
Date: Tue, 18 Feb 2020 16:18:09 +0100 [thread overview]
Message-ID: <20200218151812.7816-3-geert+renesas@glider.be> (raw)
In-Reply-To: <20200218151812.7816-1-geert+renesas@glider.be>
Currently GPIOs can only be referred to by GPIO controller and offset in
GPIO lookup tables.
Add support for looking them up by line name.
Rename gpiod_lookup.chip_label to gpiod_lookup.key, to make it clear
that this field can have two meanings, and update the kerneldoc and
GPIO_LOOKUP*() macros.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
---
v5:
- Add Reviewed-by, Tested-by,
v4:
- Add Reviewed-by,
- Rename gpiod_lookup.chip_label.
- Use U16_MAX instead of (u16)-1,
v3:
- New.
---
drivers/gpio/gpiolib.c | 22 +++++++++++++++++-----
include/linux/gpio/machine.h | 15 ++++++++-------
2 files changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 200c2d2be4b78043..24c02167f9e5472f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4453,7 +4453,7 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
if (!table)
return desc;
- for (p = &table->table[0]; p->chip_label; p++) {
+ for (p = &table->table[0]; p->key; p++) {
struct gpio_chip *chip;
/* idx must always match exactly */
@@ -4464,18 +4464,30 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
continue;
- chip = find_chip_by_name(p->chip_label);
+ if (p->chip_hwnum == U16_MAX) {
+ desc = gpio_name_to_desc(p->key);
+ if (desc) {
+ *flags = p->flags;
+ return desc;
+ }
+
+ dev_warn(dev, "cannot find GPIO line %s, deferring\n",
+ p->key);
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ chip = find_chip_by_name(p->key);
if (!chip) {
/*
* As the lookup table indicates a chip with
- * p->chip_label should exist, assume it may
+ * p->key should exist, assume it may
* still appear later and let the interested
* consumer be probed again or let the Deferred
* Probe infrastructure handle the error.
*/
dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
- p->chip_label);
+ p->key);
return ERR_PTR(-EPROBE_DEFER);
}
@@ -4506,7 +4518,7 @@ static int platform_gpio_count(struct device *dev, const char *con_id)
if (!table)
return -ENOENT;
- for (p = &table->table[0]; p->chip_label; p++) {
+ for (p = &table->table[0]; p->key; p++) {
if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
(!con_id && !p->con_id))
count++;
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index 1ebe5be05d5f81fa..84c66fbf54fd5811 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -20,8 +20,9 @@ enum gpio_lookup_flags {
/**
* struct gpiod_lookup - lookup table
- * @chip_label: name of the chip the GPIO belongs to
- * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO
+ * @key: either the name of the chip the GPIO belongs to, or the GPIO line name
+ * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO, or
+ * U16_MAX to indicate that @key is a GPIO line name
* @con_id: name of the GPIO from the device's point of view
* @idx: index of the GPIO in case several GPIOs share the same name
* @flags: bitmask of gpio_lookup_flags GPIO_* values
@@ -30,7 +31,7 @@ enum gpio_lookup_flags {
* functions using platform data.
*/
struct gpiod_lookup {
- const char *chip_label;
+ const char *key;
u16 chip_hwnum;
const char *con_id;
unsigned int idx;
@@ -63,17 +64,17 @@ struct gpiod_hog {
/*
* Simple definition of a single GPIO under a con_id
*/
-#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \
- GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags)
+#define GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags) \
+ GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, 0, _flags)
/*
* Use this macro if you need to have several GPIOs under the same con_id.
* Each GPIO needs to use a different index and can be accessed using
* gpiod_get_index()
*/
-#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags) \
+#define GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, _idx, _flags) \
{ \
- .chip_label = _chip_label, \
+ .key = _key, \
.chip_hwnum = _chip_hwnum, \
.con_id = _con_id, \
.idx = _idx, \
--
2.17.1
next prev parent reply other threads:[~2020-02-18 15:18 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 15:18 [PATCH v5 0/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 1/5] gpiolib: Add support for gpiochipN-based table lookup Geert Uytterhoeven
2020-03-12 14:23 ` Linus Walleij
2020-03-17 8:41 ` Geert Uytterhoeven
2020-02-18 15:18 ` Geert Uytterhoeven [this message]
2020-02-19 10:17 ` [PATCH v5 2/5] gpiolib: Add support for GPIO line " Geert Uytterhoeven
2020-03-12 14:21 ` Linus Walleij
2020-03-17 8:48 ` Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 3/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
2020-03-12 14:57 ` Linus Walleij
2020-03-17 10:50 ` Geert Uytterhoeven
2020-03-17 11:32 ` Geert Uytterhoeven
2020-02-18 15:18 ` [PATCH v5 4/5] docs: gpio: Add GPIO Aggregator documentation Geert Uytterhoeven
2020-02-18 18:29 ` Randy Dunlap
2020-02-18 19:09 ` Geert Uytterhoeven
2020-02-21 16:34 ` Geert Uytterhoeven
2020-02-21 16:35 ` Randy Dunlap
2020-02-18 15:18 ` [PATCH v5 5/5] MAINTAINERS: Add GPIO Aggregator section Geert Uytterhoeven
2020-02-18 17:04 ` [PATCH v5 0/5] gpio: Add GPIO Aggregator Eugeniu Rosca
2020-02-21 16:39 ` Geert Uytterhoeven
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