usb/isp1760: Allow to optionally trigger low-level chip reset via GPIOLIB.
Properly triggering the reset wire is necessary with the ISP1761 used
on Terasic DE4 Altera-FPGA boards using a NIOS2 processor, for example.
This is an optional implementation for the OF binding only. The other
bindings just pass an invalid GPIO to the isp1760_register() routine.
Example, usage in DTS:
gpios = <&pio_isp1761rst_0 0 1>;
to point to a GPIO controller from within the ISP1761 node: GPIO 0, active low.
Signed-off-by: Joachim Foerster <joachim.foerster@missinglinkelectronics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/isp1760-if.c b/drivers/usb/host/isp1760-if.c
index 791792d..2c7fc83 100644
--- a/drivers/usb/host/isp1760-if.c
+++ b/drivers/usb/host/isp1760-if.c
@@ -18,10 +18,12 @@
#include "isp1760-hcd.h"
#ifdef CONFIG_OF
+#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
+#include <linux/of_gpio.h>
#endif
#ifdef CONFIG_PCI
@@ -29,9 +31,14 @@
#endif
#ifdef CONFIG_OF
+struct isp1760 {
+ struct usb_hcd *hcd;
+ int rst_gpio;
+};
+
static int of_isp1760_probe(struct platform_device *dev)
{
- struct usb_hcd *hcd;
+ struct isp1760 *drvdata;
struct device_node *dp = dev->dev.of_node;
struct resource *res;
struct resource memory;
@@ -41,6 +48,11 @@
int ret;
const unsigned int *prop;
unsigned int devflags = 0;
+ enum of_gpio_flags gpio_flags;
+
+ drvdata = kzalloc(sizeof(*drvdata), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
ret = of_address_to_resource(dp, 0, &memory);
if (ret)
@@ -80,32 +92,57 @@
if (of_get_property(dp, "dreq-polarity", NULL) != NULL)
devflags |= ISP1760_FLAG_DREQ_POL_HIGH;
- hcd = isp1760_register(memory.start, res_len, virq,
- IRQF_SHARED, &dev->dev, dev_name(&dev->dev),
- devflags);
- if (IS_ERR(hcd)) {
- ret = PTR_ERR(hcd);
- goto release_reg;
+ drvdata->rst_gpio = of_get_gpio_flags(dp, 0, &gpio_flags);
+ if (gpio_is_valid(drvdata->rst_gpio)) {
+ ret = gpio_request(drvdata->rst_gpio, dev_name(&dev->dev));
+ if (!ret) {
+ if (!(gpio_flags & OF_GPIO_ACTIVE_LOW)) {
+ devflags |= ISP1760_FLAG_RESET_ACTIVE_HIGH;
+ gpio_direction_output(drvdata->rst_gpio, 0);
+ } else {
+ gpio_direction_output(drvdata->rst_gpio, 1);
+ }
+ } else {
+ drvdata->rst_gpio = ret;
+ }
}
- dev_set_drvdata(&dev->dev, hcd);
+ drvdata->hcd = isp1760_register(memory.start, res_len, virq,
+ IRQF_SHARED, drvdata->rst_gpio,
+ &dev->dev, dev_name(&dev->dev),
+ devflags);
+ if (IS_ERR(drvdata->hcd)) {
+ ret = PTR_ERR(drvdata->hcd);
+ goto free_gpio;
+ }
+
+ dev_set_drvdata(&dev->dev, drvdata);
return ret;
+free_gpio:
+ if (gpio_is_valid(drvdata->rst_gpio))
+ gpio_free(drvdata->rst_gpio);
release_reg:
release_mem_region(memory.start, res_len);
+ kfree(drvdata);
return ret;
}
static int of_isp1760_remove(struct platform_device *dev)
{
- struct usb_hcd *hcd = dev_get_drvdata(&dev->dev);
+ struct isp1760 *drvdata = dev_get_drvdata(&dev->dev);
dev_set_drvdata(&dev->dev, NULL);
- usb_remove_hcd(hcd);
- iounmap(hcd->regs);
- release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
- usb_put_hcd(hcd);
+ usb_remove_hcd(drvdata->hcd);
+ iounmap(drvdata->hcd->regs);
+ release_mem_region(drvdata->hcd->rsrc_start, drvdata->hcd->rsrc_len);
+ usb_put_hcd(drvdata->hcd);
+
+ if (gpio_is_valid(drvdata->rst_gpio))
+ gpio_free(drvdata->rst_gpio);
+
+ kfree(drvdata);
return 0;
}
@@ -242,7 +279,7 @@
dev->dev.dma_mask = NULL;
hcd = isp1760_register(pci_mem_phy0, memlength, dev->irq,
- IRQF_SHARED, &dev->dev, dev_name(&dev->dev),
+ IRQF_SHARED, -ENOENT, &dev->dev, dev_name(&dev->dev),
devflags);
if (IS_ERR(hcd)) {
ret_status = -ENODEV;
@@ -353,7 +390,8 @@
}
hcd = isp1760_register(mem_res->start, mem_size, irq_res->start,
- irqflags, &pdev->dev, dev_name(&pdev->dev), devflags);
+ irqflags, -ENOENT,
+ &pdev->dev, dev_name(&pdev->dev), devflags);
if (IS_ERR(hcd)) {
pr_warning("isp1760: Failed to register the HCD device\n");
ret = -ENODEV;