[PATCH] soc: fsl: qe: request pins non-exclusively
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2022-11-08 03:17:19
Also in:
linux-usb, linuxppc-dev, lkml
Subsystem:
freescale quicc engine library, freescale soc drivers, the rest, usb subsystem · Maintainers:
Qiang Zhao, Christophe Leroy, Linus Torvalds, Greg Kroah-Hartman
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@gmail.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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