On Thursday, May 07, 2009 3:09 PM, Ryan Mallon wrote:
> You can (and should) use platform_driver_probe and still have the
> module be loadable. For the gpio settings, I think that probably
> the best approach is to use gpio_request for each of the gpio pins
> so that gpio_lib knows that they are in use and sysfs/debugfs will
> correctly show they are assigned to ide, and then call
> ep93xx_ide_on_gpio, so you will have something like in your init code:
Hmmm...
How about doing all the request/free's in the ep93xx_ide_on_gpio()
function? That way the platform code can initially call it and set
all the pins into gpio mode (freeing them). Then later when the
IDE driver is loaded it can call the function to try and put the
pins into IDE mode (requesting them). If any of the pins are
unavailable the ep93xx_ide_on_gpio() function can return the
necessary error code preventing the IDE driver from loading. When
the driver is unloaded it just needs to call the core to free
the gpio's.
Something like:
int ep93xx_ide_on_gpio(int enable)
{
u32 reg;
int err;
int i;
reg = __raw_read(EP93XX_SYSCON_DEVICE_CONFIG);
if (enable) {
for (i = 0; i < 8; i++) {
err = gpio_request(EP93XX_GPIO_LINE_E(i), "ep93xx_ide");
if (err)
goto fail_gpio_e;
err = gpio_request(EP93XX_GPIO_LINE_F(i), "ep93xx_ide");
if (err)
goto fail_gpio_f;
err = gpio_request(EP93XX_GPIO_LINE_G(i), "ep93xx_ide");
if (err)
goto fail_gpio_g;
}
reg &= ~(EP93XX_SYSCON_DEVICE_CONFIG_EONIDE |
EP93XX_SYSCON_DEVICE_CONFIG_GONIDE |
EP93XX_SYSCON_DEVICE_CONFIG_HONIDE);
} else {
for (i = 0; i < 8; i++) {
gpio_free(EP93XX_GPIO_LINE_E(i));
gpio_free(EP93XX_GPIO_LINE_F(i));
gpio_free(EP93XX_GPIO_LINE_G(i));
}
reg |= (EP93XX_SYSCON_DEVICE_CONFIG_EONIDE |
EP93XX_SYSCON_DEVICE_CONFIG_GONIDE |
EP93XX_SYSCON_DEVICE_CONFIG_HONIDE);
}
__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
__raw_writel(reg, EP93XX_SYSCON_DEVICE_CONFIG);
return 0;
fail_gpio_g:
free_gpio(EP93XX_GPIO_LINE_F(i);
fail_gpio_f:
free_gpio(EP93XX_GPIO_LINE_E(i);
fail_gpio_e:
for ( ; i >= 0; --i) {
free_gpio(EP93XX_GPIO_LINE_E(i);
free_gpio(EP93XX_GPIO_LINE_F(i);
free_gpio(EP93XX_GPIO_LINE_G(i);
}
return err;
}
Regards,
Hartley
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