On Tue, Jan 12, 2016 at 03:41:39PM +0800, Peter Hung wrote: > Dont export gpios which not enabled by motherboard manufacturer. > > Signed-off-by: Peter Hung <hpeter+linux_kernel@xxxxxxxxx> Hi Peter, > --- > drivers/gpio/gpio-f7188x.c | 153 +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 153 insertions(+) > > diff --git a/drivers/gpio/gpio-f7188x.c b/drivers/gpio/gpio-f7188x.c > index a6a9641..f7fe7aa 100644 > --- a/drivers/gpio/gpio-f7188x.c > +++ b/drivers/gpio/gpio-f7188x.c > @@ -38,6 +38,12 @@ > #define SIO_F71889_ID 0x0909 /* F71889 chipset ID */ > #define SIO_F81866_ID 0x1010 /* F81866 chipset ID */ > > +#define F81866_PORT_SEL_REG 0x27 > +#define F81866_MULTI_FUN1_REG 0x28 > +#define F81866_MULTI_FUN3_REG 0x29 > +#define F81866_MULTI_FUN4_REG 0x2B > +#define F81866_GPIO_EN_REG 0x2C > + > enum chips { f71869, f71869a, f71882fg, f71889f, f81866 }; > > static const char * const f7188x_names[] = { > @@ -93,6 +99,15 @@ static inline void superio_outb(int base, int reg, int val) > outb(val, base + 1); > } > > +static inline void superio_mask_outb(int base, int reg, int mask, int val) > +{ > + u8 tmp; > + > + tmp = superio_inb(base, reg); > + tmp = (tmp & ~mask) | (val & mask); > + superio_outb(base, reg, tmp); > +} > + > static inline int superio_enter(int base) > { > /* Don't step on other drivers' I/O space by accident. */ > @@ -304,6 +319,125 @@ static void f7188x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) > superio_exit(sio->addr); > } > > +static int f81866_verify_gpioset(int base, int set) > +{ > + int err; > + u8 tmp; > + > + err = superio_enter(base); > + if (err) > + return err; > + > + err = -ENODEV; > + > + switch (set) { > + case 0: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2) | > + BIT(0), 0); > + tmp = superio_inb(base, F81866_GPIO_EN_REG); > + if ((tmp & 0x1f) != 0x1f) > + break; /* one in GPIO00~GPIO04 is not enable */ > + > + tmp = superio_inb(base, F81866_MULTI_FUN1_REG); > + if ((tmp & 0xc) != 0x0) > + break; > + > + err = 0; /* GPIO0x set is all enabled */ > + break; > + case 1: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2) | > + BIT(0), BIT(2)); > + tmp = superio_inb(base, F81866_GPIO_EN_REG); > + if ((tmp & 0xef) != 0xef) > + break; /* one in GPIO10~GPIO17 is not enable */ > + > + tmp = superio_inb(base, F81866_MULTI_FUN3_REG); > + if ((tmp & 0x03) != 0x00) > + break; /* one in GPIO12~GPIO13 is not enable */ > + > + err = 0; /* GPIO1x set is all enabled */ > + break; > + case 2: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2) | > + BIT(0), BIT(3)); > + tmp = superio_inb(base, F81866_GPIO_EN_REG); > + if ((tmp & 0xff) != 0xff) > + break; /* one in GPIO20~GPIO27 is not enable */ > + > + tmp = superio_inb(base, F81866_MULTI_FUN3_REG); > + if ((tmp & 0x08) != 0x00) > + break; /* GPIO20 is not enable */ > + > + err = 0; /* GPIO2x set is all enabled */ > + break; > + case 3: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(0), 0); > + tmp = superio_inb(base, F81866_MULTI_FUN3_REG); > + if ((tmp & 0x30) != 0x00) > + break; /* GPIO3x is not enable */ > + > + err = 0; /* GPIO3x set is all enabled */ > + break; > + case 4: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(0), 0); > + tmp = superio_inb(base, F81866_MULTI_FUN3_REG); > + if ((tmp & 0xc0) != 0x00) > + break; /* GPIO4x is not enable */ > + > + err = 0; /* GPIO4x set is all enabled */ > + break; > + case 5: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2), > + 0); > + tmp = superio_inb(base, F81866_MULTI_FUN1_REG); > + if ((tmp & 0x43) != 0x40) > + break; /* GPIO5x is not enable */ > + > + err = 0; /* GPIO5x set is all enabled */ > + break; > + case 6: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2) | > + BIT(0), 0); > + tmp = superio_inb(base, F81866_MULTI_FUN1_REG); > + if ((tmp & 0x4c) != 0x40) > + break; /* GPIO60~64 is not enable */ > + > + tmp = superio_inb(base, F81866_MULTI_FUN4_REG); > + if ((tmp & 0xe0) != 0xe0) > + break; /* GPIO65~67 is not enable */ > + > + err = 0; /* GPIO6x set is all enabled */ > + break; > + case 7: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2) | > + BIT(0), 0); > + tmp = superio_inb(base, F81866_MULTI_FUN1_REG); > + if ((tmp & 0x20) != 0x20) > + break; /* GPIO7x is not enable */ > + > + tmp = superio_inb(base, F81866_MULTI_FUN4_REG); > + if ((tmp & 0x01) != 0x00) > + break; /* GPIO70 is not enable */ > + > + err = 0; /* GPIO7x set is all enabled */ > + break; > + case 8: > + superio_mask_outb(base, F81866_PORT_SEL_REG, BIT(3) | BIT(2), > + 0); > + tmp = superio_inb(base, F81866_MULTI_FUN1_REG); > + if ((tmp & 0x20) != 0x20) > + break; /* GPIO8x is not enable */ > + > + err = 0; /* GPIO8x set is all enabled */ > + break; > + default: > + break; > + } > + > + superio_exit(base); > + return err; > +} > + > /* > * Platform device and driver. > */ > @@ -351,6 +485,15 @@ static int f7188x_gpio_probe(struct platform_device *pdev) > for (i = 0; i < data->nr_bank; i++) { > struct f7188x_gpio_bank *bank = &data->bank[i]; > > + /* > + * Dont export GPIO sysfs if pin set is not enable by MB > + * manufacturer. What does MB stands for ? > + */ > + if (sio->type == f81866 && f81866_verify_gpioset(sio->addr, i)) > + continue; This whole filtering mechanism relies on the fact that the multiplexing configuration has been correctly applied by the BIOS (if applied at all). But I wonder if it is often the case. For example, I have several boards for which it is not true. And to make the GPIOs available, I need first to fix the multiplexing pin configuration of the Super I/O. Maybe it would be more correct to rely on the hardware description of a board (Device Tree or ACPI) to decide which GPIO bank can be enabled or not. Simon
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