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Message-ID: <Y2nKIbKxHAMimxII@google.com>
Date: Mon, 7 Nov 2022 19:16:49 -0800
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: Qiang Zhao <qiang.zhao@....com>, Arnd Bergmann <arnd@...db.de>
Cc: Li Yang <leoyang.li@....com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Linus Walleij <linus.walleij@...aro.org>,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
linuxppc-dev@...ts.ozlabs.org,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
linux-usb@...r.kernel.org
Subject: [PATCH] soc: fsl: qe: request pins non-exclusively
Commit 84582f9ed090 ("soc: fsl: qe: Avoid using gpio_to_desc()") changed
qe_pin_request() to request and hold GPIO corresponding to a given pin.
Unfortunately this does not work, as fhci-hcd requests these GPIOs
first, befor calling qe_pin_request() (see
drivers/usb/host/fhci-hcd.c::of_fhci_probe()).
To fix it change qe_pin_request() to request GPIOs non-exclusively, and
free them once the code determines GPIO controller and offset for each
GPIO/pin.
Also reaching deep into gpiolib implementation is not the best idea. We
should either export gpio_chip_hwgpio() or keep converting to the global
gpio numbers space until we fix the driver to implement proper pin
control.
Fixes: 84582f9ed090 ("soc: fsl: qe: Avoid using gpio_to_desc()")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
Compiled only, not tested on hardware.
drivers/soc/fsl/qe/gpio.c | 71 ++++++++++++++++++-------------------
drivers/usb/host/fhci-hcd.c | 2 +-
include/soc/fsl/qe/qe.h | 5 +--
3 files changed, 38 insertions(+), 40 deletions(-)
diff --git a/drivers/soc/fsl/qe/gpio.c b/drivers/soc/fsl/qe/gpio.c
index 0ee887f89deb..5bb71a2b5b7a 100644
--- a/drivers/soc/fsl/qe/gpio.c
+++ b/drivers/soc/fsl/qe/gpio.c
@@ -13,7 +13,7 @@
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
-#include <linux/of_gpio.h>
+#include <linux/of_gpio.h> /* for of_mm_gpio_chip */
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/slab.h>
@@ -21,13 +21,6 @@
#include <linux/property.h>
#include <soc/fsl/qe/qe.h>
-/*
- * FIXME: this is legacy code that is accessing gpiolib internals in order
- * to implement a custom pin controller. The proper solution is to create
- * a real combined pin control and GPIO driver in drivers/pinctrl. However
- * this hack is here for legacy code reasons.
- */
-#include "../../../gpio/gpiolib.h"
struct qe_gpio_chip {
struct of_mm_gpio_chip mm_gc;
@@ -149,20 +142,19 @@ struct qe_pin {
* something like qe_pio_controller. Someday.
*/
struct qe_gpio_chip *controller;
- struct gpio_desc *gpiod;
int num;
};
/**
* qe_pin_request - Request a QE pin
- * @np: device node to get a pin from
- * @index: index of a pin in the device tree
+ * @dev: device to get the pin from
+ * @index: index of the pin in the device tree
* Context: non-atomic
*
* This function return qe_pin so that you could use it with the rest of
* the QE Pin Multiplexing API.
*/
-struct qe_pin *qe_pin_request(struct device_node *np, int index)
+struct qe_pin *qe_pin_request(struct device *dev, int index)
{
struct qe_pin *qe_pin;
struct gpio_chip *gc;
@@ -171,40 +163,46 @@ struct qe_pin *qe_pin_request(struct device_node *np, int index)
qe_pin = kzalloc(sizeof(*qe_pin), GFP_KERNEL);
if (!qe_pin) {
- pr_debug("%s: can't allocate memory\n", __func__);
+ dev_dbg(dev, "%s: can't allocate memory\n", __func__);
return ERR_PTR(-ENOMEM);
}
- gpiod = fwnode_gpiod_get_index(of_fwnode_handle(np), NULL, index, GPIOD_ASIS, "qe");
- if (IS_ERR(gpiod)) {
- err = PTR_ERR(gpiod);
- goto err0;
- }
- if (!gpiod) {
- err = -EINVAL;
+ /*
+ * Request gpio as nonexclusive as it was likely was reserved by
+ * the caller, and we are not planning on controlling it, we only
+ * need the descriptor to the to the gpio chip structure.
+ */
+ gpiod = gpiod_get_index(dev, NULL, index,
+ GPIOD_ASIS | GPIOD_FLAGS_BIT_NONEXCLUSIVE);
+ err = PTR_ERR_OR_ZERO(gpiod);
+ if (err)
goto err0;
- }
+
gc = gpiod_to_chip(gpiod);
if (WARN_ON(!gc)) {
err = -ENODEV;
goto err0;
- }
- qe_pin->gpiod = gpiod;
- qe_pin->controller = gpiochip_get_data(gc);
- /*
- * FIXME: this gets the local offset on the gpio_chip so that the driver
- * can manipulate pin control settings through its custom API. The real
- * solution is to create a real pin control driver for this.
- */
- qe_pin->num = gpio_chip_hwgpio(gpiod);
-
- if (!fwnode_device_is_compatible(gc->fwnode, "fsl,mpc8323-qe-pario-bank")) {
- pr_debug("%s: tried to get a non-qe pin\n", __func__);
- gpiod_put(gpiod);
+ } else if (!fwnode_device_is_compatible(gc->fwnode,
+ "fsl,mpc8323-qe-pario-bank")) {
+ dev_dbg(dev, "%s: tried to get a non-qe pin\n", __func__);
err = -EINVAL;
- goto err0;
+ } else {
+ qe_pin->controller = gpiochip_get_data(gc);
+ /*
+ * FIXME: this gets the local offset on the gpio_chip so that
+ * the driver can manipulate pin control settings through its
+ * custom API. The real solution is to create a real pin control
+ * driver for this.
+ */
+ qe_pin->num = desc_to_gpio(gpiod) - gc->base;
}
- return qe_pin;
+
+ /* We no longer need this descriptor */
+ gpiod_put(gpiod);
+
+ if (!err)
+ return qe_pin;
+
err0:
kfree(qe_pin);
pr_debug("%s failed with status %d\n", __func__, err);
@@ -222,7 +220,6 @@ EXPORT_SYMBOL(qe_pin_request);
*/
void qe_pin_free(struct qe_pin *qe_pin)
{
- gpiod_put(qe_pin->gpiod);
kfree(qe_pin);
}
EXPORT_SYMBOL(qe_pin_free);
diff --git a/drivers/usb/host/fhci-hcd.c b/drivers/usb/host/fhci-hcd.c
index 95a44462bed0..1f666804fa91 100644
--- a/drivers/usb/host/fhci-hcd.c
+++ b/drivers/usb/host/fhci-hcd.c
@@ -651,7 +651,7 @@ static int of_fhci_probe(struct platform_device *ofdev)
}
for (j = 0; j < NUM_PINS; j++) {
- fhci->pins[j] = qe_pin_request(node, j);
+ fhci->pins[j] = qe_pin_request(dev, j);
if (IS_ERR(fhci->pins[j])) {
ret = PTR_ERR(fhci->pins[j]);
dev_err(dev, "can't get pin %d: %d\n", j, ret);
diff --git a/include/soc/fsl/qe/qe.h b/include/soc/fsl/qe/qe.h
index b02e9fe69146..eb5079904cc8 100644
--- a/include/soc/fsl/qe/qe.h
+++ b/include/soc/fsl/qe/qe.h
@@ -172,14 +172,15 @@ static inline int par_io_data_set(u8 port, u8 pin, u8 val) { return -ENOSYS; }
/*
* Pin multiplexing functions.
*/
+struct device;
struct qe_pin;
#ifdef CONFIG_QE_GPIO
-extern struct qe_pin *qe_pin_request(struct device_node *np, int index);
+extern struct qe_pin *qe_pin_request(struct device *dev, int index);
extern void qe_pin_free(struct qe_pin *qe_pin);
extern void qe_pin_set_gpio(struct qe_pin *qe_pin);
extern void qe_pin_set_dedicated(struct qe_pin *pin);
#else
-static inline struct qe_pin *qe_pin_request(struct device_node *np, int index)
+static inline struct qe_pin *qe_pin_request(struct device *dev, int index)
{
return ERR_PTR(-ENOSYS);
}
--
2.38.1.431.g37b22c650d-goog
--
Dmitry
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