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Date: Wed, 15 Jan 2020 19:15:20 +0100
From: Geert Uytterhoeven <geert+renesas@...der.be>
To: Linus Walleij <linus.walleij@...aro.org>,
Bartosz Golaszewski <bgolaszewski@...libre.com>,
Jonathan Corbet <corbet@....net>,
Harish Jenny K N <harish_kandiga@...tor.com>,
Eugeniu Rosca <erosca@...adit-jv.com>
Cc: Alexander Graf <graf@...zon.com>,
Peter Maydell <peter.maydell@...aro.org>,
Paolo Bonzini <pbonzini@...hat.com>,
Phil Reid <preid@...ctromag.com.au>,
Marc Zyngier <marc.zyngier@....com>,
Christoffer Dall <christoffer.dall@....com>,
Magnus Damm <magnus.damm@...il.com>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
linux-gpio@...r.kernel.org, linux-doc@...r.kernel.org,
linux-renesas-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
qemu-devel@...gnu.org, Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH v4 2/5] gpiolib: Add support for GPIO line table lookup
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@...der.be>
Reviewed-by: Ulrich Hecht <uli+renesas@...nd.eu>
---
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 114325b366ae33d5..48fc6cf9a020f4ff 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -4457,7 +4457,7 @@ 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 */
@@ -4468,18 +4468,30 @@ 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);
}
@@ -4510,7 +4522,7 @@ 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
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