[PATCH V2] gpio: brcmstb: support gpio-line-names property

From: Doug Berger
Date: Mon Mar 09 2020 - 15:02:29 EST


The default handling of the gpio-line-names property by the
gpiolib-of implementation does not work with the multiple
gpiochip banks per device structure used by the gpio-brcmstb
driver.

This commit adds driver level support for the device tree
property so that GPIO lines can be assigned friendly names.

Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
---
drivers/gpio/gpio-brcmstb.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 44 insertions(+)

diff --git a/drivers/gpio/gpio-brcmstb.c b/drivers/gpio/gpio-brcmstb.c
index 05e3f99ae59c..fcfc1a1f1a5c 100644
--- a/drivers/gpio/gpio-brcmstb.c
+++ b/drivers/gpio/gpio-brcmstb.c
@@ -603,6 +603,49 @@ static const struct dev_pm_ops brcmstb_gpio_pm_ops = {
.resume_noirq = brcmstb_gpio_resume,
};

+static void brcmstb_gpio_set_names(struct device *dev,
+ struct brcmstb_gpio_bank *bank)
+{
+ struct device_node *np = dev->of_node;
+ const char **names;
+ int nstrings, base;
+ unsigned int i;
+
+ base = bank->id * MAX_GPIO_PER_BANK;
+
+ nstrings = of_property_count_strings(np, "gpio-line-names");
+ if (nstrings <= base)
+ /* Line names not present */
+ return;
+
+ names = devm_kcalloc(dev, MAX_GPIO_PER_BANK, sizeof(*names),
+ GFP_KERNEL);
+ if (!names)
+ return;
+
+ /*
+ * Make sure to not index beyond the end of the number of descriptors
+ * of the GPIO device.
+ */
+ for (i = 0; i < bank->width; i++) {
+ const char *name;
+ int ret;
+
+ ret = of_property_read_string_index(np, "gpio-line-names",
+ base + i, &name);
+ if (ret) {
+ if (ret != -ENODATA)
+ dev_err(dev, "unable to name line %d: %d\n",
+ base + i, ret);
+ break;
+ }
+ if (*name)
+ names[i] = name;
+ }
+
+ bank->gc.names = names;
+}
+
static int brcmstb_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -726,6 +769,7 @@ static int brcmstb_gpio_probe(struct platform_device *pdev)
need_wakeup_event |= !!__brcmstb_gpio_get_active_irqs(bank);
gc->write_reg(reg_base + GIO_MASK(bank->id), 0);

+ brcmstb_gpio_set_names(dev, bank);
err = gpiochip_add_data(gc, bank);
if (err) {
dev_err(dev, "Could not add gpiochip for bank %d\n",
--
2.7.4