Re: [PATCH v4] gpio: winbond: add driver

From: Maciej S. Szmigiero
Date: Fri Jan 05 2018 - 18:41:40 EST


On 05.01.2018 14:35, Andy Shevchenko wrote:
> On Thu, 2018-01-04 at 22:46 +0100, Maciej S. Szmigiero wrote:
>> This commit adds GPIO driver for Winbond Super I/Os.
>>
>> Currently, only W83627UHG model (also known as Nuvoton NCT6627UD) is
>> supported but in the future a support for other Winbond models, too,
>> can
>> be added to the driver.
>>
>> A module parameter "gpios" sets a bitmask of GPIO ports to enable (bit
>> 0 is
>> GPIO1, bit 1 is GPIO2, etc.).
>> One should be careful which ports one tinkers with since some might be
>> managed by the firmware (for functions like powering on and off,
>> sleeping,
>> BIOS recovery, etc.) and some of GPIO port pins are physically shared
>> with
>> other devices included in the Super I/O chip.
>>
>
> I still have an impression that it could be MFD based driver will all
> infrastructure needed for the actual devices behind, though here is an
> objection from the author, so, I leave it to maintainers.
>
> Besides that I don't like global variables in so many amount (perhaps
> custom struct gpio_w83227uhg {...}; static struct ... *...; might
> improve this.
>
> And one nit below.
>
> So, there is room for improvement for my opinion, anyway, FWIW,
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

Thanks,
will implement your comments about grouping global parameters in
a single static struct and about __clear_bit in a respin.

Maciej

>> Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
>> ---
>> Changes from v1:
>> * Added SPDX license tag,
>>
>> * Removed gpiobase parameter,
>>
>> * Changed uint{8,16}_t types to u{8,16},
>>
>> * Added kerneldoc descriptions of driver structures,
>>
>> * Reformatted winbond_gpio_infos array fields so they are on separate
>> lines,
>>
>> * Added few comments here and there as requested,
>>
>> * Moved port configuration code from separate
>> winbond_gpio_configure_X()
>> functions to one, common, parametrized winbond_gpio_configure_port()
>> function.
>>
>> Changes from v2:
>> * Adapted the driver to use the ISA bus instead of the platform one,
>>
>> * Reformatted register and register bit macros,
>>
>> * Added wb_sio_{notice,warn,err} macros to not repeat pr_* calls with
>> the same prefix again and again,
>>
>> * Added a comment why a double I/O register write is needed,
>>
>> * Converted the code to use for_each_set_bit() where it could be used,
>>
>> * Removed a warning about an impossible condition in
>> winbond_gpio_get_info(),
>>
>> * Made winbond_gpio_get_info() return a reduced GPIO number,
>>
>> * Renamed gpiolib callback functions parameter name from gpio_num to
>> offset,
>>
>> * Changed I/O port number variables to unsigned long type,
>>
>> * Removed explicit casts in logging calls,
>>
>> * hweight() is now used for calculating the total GPIO count.
>>
>> Changes from v3:
>> * Changed the code to use pr_fmt(x) instead of
>> wb_sio_{notice,warn,err}
>> logging macros,
>>
>> * Made the driver warn about but accept extra bits in the "gpios"
>> parameter,
>>
>> * Removed a one case of a redundant 'else',
>>
>> * Swapped a one missed pair of register bit macros,
>>
>> * Changed the code to pass a size in bits, not bytes, to
>> for_each_set_bit() macros.
>>
>> drivers/gpio/Kconfig | 16 +
>> drivers/gpio/Makefile | 1 +
>> drivers/gpio/gpio-winbond.c | 723
>> ++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 740 insertions(+)
>> create mode 100644 drivers/gpio/gpio-winbond.c
>>
>> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
>> index 395669bfcc26..8c4018855c3b 100644
>> --- a/drivers/gpio/Kconfig
>> +++ b/drivers/gpio/Kconfig
>> @@ -698,6 +698,22 @@ config GPIO_TS5500
>> blocks of the TS-5500: DIO1, DIO2 and the LCD port, and the
>> TS-5600
>> LCD port.
>>
>> +config GPIO_WINBOND
>> + tristate "Winbond Super I/O GPIO support"
>> + select ISA_BUS_API
>> + help
>> + This option enables support for GPIOs found on Winbond
>> Super I/O
>> + chips.
>> + Currently, only W83627UHG (also known as Nuvoton NCT6627UD)
>> is
>> + supported.
>> +
>> + You will need to provide a module parameter "gpios", or a
>> + boot-time parameter "gpio_winbond.gpios" with a bitmask of
>> GPIO
>> + ports to enable (bit 0 is GPIO1, bit 1 is GPIO2, etc.).
>> +
>> + To compile this driver as a module, choose M here: the
>> module will
>> + be called gpio-winbond.
>> +
>> config GPIO_WS16C48
>> tristate "WinSystems WS16C48 GPIO support"
>> depends on ISA_BUS_API
>> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
>> index bc5dd673fa11..ff3d36d0a443 100644
>> --- a/drivers/gpio/Makefile
>> +++ b/drivers/gpio/Makefile
>> @@ -139,6 +139,7 @@ obj-$(CONFIG_GPIO_VIPERBOARD) += gpio-
>> viperboard.o
>> obj-$(CONFIG_GPIO_VR41XX) += gpio-vr41xx.o
>> obj-$(CONFIG_GPIO_VX855) += gpio-vx855.o
>> obj-$(CONFIG_GPIO_WHISKEY_COVE) += gpio-wcove.o
>> +obj-$(CONFIG_GPIO_WINBOND) += gpio-winbond.o
>> obj-$(CONFIG_GPIO_WM831X) += gpio-wm831x.o
>> obj-$(CONFIG_GPIO_WM8350) += gpio-wm8350.o
>> obj-$(CONFIG_GPIO_WM8994) += gpio-wm8994.o
>> diff --git a/drivers/gpio/gpio-winbond.c b/drivers/gpio/gpio-winbond.c
>> new file mode 100644
>> index 000000000000..a06a47f3dcdf
>> --- /dev/null
>> +++ b/drivers/gpio/gpio-winbond.c
>> @@ -0,0 +1,723 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * GPIO interface for Winbond Super I/O chips
>> + * Currently, only W83627UHG (Nuvoton NCT6627UD) is supported.
>> + *
>> + * Author: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
>> + */
>> +
>> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
>> +
>> +#include <linux/gpio/driver.h>
>> +#include <linux/ioport.h>
>> +#include <linux/isa.h>
>> +#include <linux/module.h>
>> +
>> +#define WB_GPIO_DRIVER_NAME KBUILD_MODNAME
>> +
>> +#define WB_SIO_BASE 0x2e
>> +#define WB_SIO_BASE_HIGH 0x4e
>> +
>> +#define WB_SIO_EXT_ENTER_KEY 0x87
>> +#define WB_SIO_EXT_EXIT_KEY 0xaa
>> +
>> +/* global chip registers */
>> +
>> +#define WB_SIO_REG_LOGICAL 0x07
>> +
>> +#define WB_SIO_REG_CHIP_MSB 0x20
>> +#define WB_SIO_REG_CHIP_LSB 0x21
>> +
>> +#define WB_SIO_CHIP_ID_W83627UHG 0xa230
>> +#define WB_SIO_CHIP_ID_W83627UHG_MASK GENMASK(15, 4)
>> +
>> +#define WB_SIO_REG_DPD 0x22
>> +#define WB_SIO_REG_DPD_UARTA 4
>> +#define WB_SIO_REG_DPD_UARTB 5
>> +
>> +#define WB_SIO_REG_IDPD 0x23
>> +#define WB_SIO_REG_IDPD_UARTC 4
>> +#define WB_SIO_REG_IDPD_UARTD 5
>> +#define WB_SIO_REG_IDPD_UARTE 6
>> +#define WB_SIO_REG_IDPD_UARTF 7
>> +
>> +#define WB_SIO_REG_GLOBAL_OPT 0x24
>> +#define WB_SIO_REG_GO_ENFDC 1
>> +
>> +#define WB_SIO_REG_OVTGPIO3456 0x29
>> +#define WB_SIO_REG_OG3456_G3PP 3
>> +#define WB_SIO_REG_OG3456_G4PP 4
>> +#define WB_SIO_REG_OG3456_G5PP 5
>> +#define WB_SIO_REG_OG3456_G6PP 7
>> +
>> +#define WB_SIO_REG_I2C_PS 0x2a
>> +#define WB_SIO_REG_I2CPS_I2CFS 1
>> +
>> +#define WB_SIO_REG_GPIO1_MF 0x2c
>> +#define WB_SIO_REG_G1MF_G1PP 6
>> +#define WB_SIO_REG_G1MF_G2PP 7
>> +#define WB_SIO_REG_G1MF_FS_MASK GENMASK(1, 0)
>> +#define WB_SIO_REG_G1MF_FS_IR_OFF 0
>> +#define WB_SIO_REG_G1MF_FS_IR 1
>> +#define WB_SIO_REG_G1MF_FS_GPIO1 2
>> +#define WB_SIO_REG_G1MF_FS_UARTB 3
>> +
>> +/* not an actual device number, just a value meaning 'no device' */
>> +#define WB_SIO_DEV_NONE 0xff
>> +
>> +/* registers with offsets >= 0x30 are specific for a particular
>> device */
>> +
>> +/* UART B logical device */
>> +#define WB_SIO_DEV_UARTB 0x03
>> +#define WB_SIO_UARTB_REG_ENABLE 0x30
>> +#define WB_SIO_UARTB_ENABLE_ON 0
>> +
>> +/* UART C logical device */
>> +#define WB_SIO_DEV_UARTC 0x06
>> +#define WB_SIO_UARTC_REG_ENABLE 0x30
>> +#define WB_SIO_UARTC_ENABLE_ON 0
>> +
>> +/* GPIO3, GPIO4 logical device */
>> +#define WB_SIO_DEV_GPIO34 0x07
>> +#define WB_SIO_GPIO34_REG_ENABLE 0x30
>> +#define WB_SIO_GPIO34_ENABLE_3 0
>> +#define WB_SIO_GPIO34_ENABLE_4 1
>> +#define WB_SIO_GPIO34_REG_IO3 0xe0
>> +#define WB_SIO_GPIO34_REG_DATA3 0xe1
>> +#define WB_SIO_GPIO34_REG_INV3 0xe2
>> +#define WB_SIO_GPIO34_REG_IO4 0xe4
>> +#define WB_SIO_GPIO34_REG_DATA4 0xe5
>> +#define WB_SIO_GPIO34_REG_INV4 0xe6
>> +
>> +/* WDTO, PLED, GPIO5, GPIO6 logical device */
>> +#define WB_SIO_DEV_WDGPIO56 0x08
>> +#define WB_SIO_WDGPIO56_REG_ENABLE 0x30
>> +#define WB_SIO_WDGPIO56_ENABLE_5 1
>> +#define WB_SIO_WDGPIO56_ENABLE_6 2
>> +#define WB_SIO_WDGPIO56_REG_IO5 0xe0
>> +#define WB_SIO_WDGPIO56_REG_DATA5 0xe1
>> +#define WB_SIO_WDGPIO56_REG_INV5 0xe2
>> +#define WB_SIO_WDGPIO56_REG_IO6 0xe4
>> +#define WB_SIO_WDGPIO56_REG_DATA6 0xe5
>> +#define WB_SIO_WDGPIO56_REG_INV6 0xe6
>> +
>> +/* GPIO1, GPIO2, SUSLED logical device */
>> +#define WB_SIO_DEV_GPIO12 0x09
>> +#define WB_SIO_GPIO12_REG_ENABLE 0x30
>> +#define WB_SIO_GPIO12_ENABLE_1 0
>> +#define WB_SIO_GPIO12_ENABLE_2 1
>> +#define WB_SIO_GPIO12_REG_IO1 0xe0
>> +#define WB_SIO_GPIO12_REG_DATA1 0xe1
>> +#define WB_SIO_GPIO12_REG_INV1 0xe2
>> +#define WB_SIO_GPIO12_REG_IO2 0xe4
>> +#define WB_SIO_GPIO12_REG_DATA2 0xe5
>> +#define WB_SIO_GPIO12_REG_INV2 0xe6
>> +
>> +/* UART D logical device */
>> +#define WB_SIO_DEV_UARTD 0x0d
>> +#define WB_SIO_UARTD_REG_ENABLE 0x30
>> +#define WB_SIO_UARTD_ENABLE_ON 0
>> +
>> +/* UART E logical device */
>> +#define WB_SIO_DEV_UARTE 0x0e
>> +#define WB_SIO_UARTE_REG_ENABLE 0x30
>> +#define WB_SIO_UARTE_ENABLE_ON 0
>> +
>> +static unsigned long baseparam;
>> +static unsigned long gpios;
>> +static unsigned long ppgpios;
>> +static unsigned long odgpios;
>> +static bool pledgpio;
>> +static bool beepgpio;
>> +static bool i2cgpio;
>> +
>> +static int winbond_sio_enter(unsigned long base)
>> +{
>> + if (!request_muxed_region(base, 2, WB_GPIO_DRIVER_NAME))
>> + return -EBUSY;
>> +
>> + /*
>> + * datasheet says two successive writes of the "key" value
>> are needed
>> + * in order for chip to enter the "Extended Function Mode"
>> + */
>> + outb(WB_SIO_EXT_ENTER_KEY, base);
>> + outb(WB_SIO_EXT_ENTER_KEY, base);
>> +
>> + return 0;
>> +}
>> +
>> +static void winbond_sio_select_logical(unsigned long base, u8 dev)
>> +{
>> + outb(WB_SIO_REG_LOGICAL, base);
>> + outb(dev, base + 1);
>> +}
>> +
>> +static void winbond_sio_leave(unsigned long base)
>> +{
>> + outb(WB_SIO_EXT_EXIT_KEY, base);
>> +
>> + release_region(base, 2);
>> +}
>> +
>> +static void winbond_sio_reg_write(unsigned long base, u8 reg, u8
>> data)
>> +{
>> + outb(reg, base);
>> + outb(data, base + 1);
>> +}
>> +
>> +static u8 winbond_sio_reg_read(unsigned long base, u8 reg)
>> +{
>> + outb(reg, base);
>> + return inb(base + 1);
>> +}
>> +
>> +static void winbond_sio_reg_bset(unsigned long base, u8 reg, u8 bit)
>> +{
>> + u8 val;
>> +
>> + val = winbond_sio_reg_read(base, reg);
>> + val |= BIT(bit);
>> + winbond_sio_reg_write(base, reg, val);
>> +}
>> +
>> +static void winbond_sio_reg_bclear(unsigned long base, u8 reg, u8
>> bit)
>> +{
>> + u8 val;
>> +
>> + val = winbond_sio_reg_read(base, reg);
>> + val &= ~BIT(bit);
>> + winbond_sio_reg_write(base, reg, val);
>> +}
>> +
>> +static bool winbond_sio_reg_btest(unsigned long base, u8 reg, u8 bit)
>> +{
>> + return winbond_sio_reg_read(base, reg) & BIT(bit);
>> +}
>> +
>> +/**
>> + * struct winbond_gpio_port_conflict - possibly conflicting device
>> information
>> + * @name: device name (NULL means no conflicting device
>> defined)
>> + * @dev: Super I/O logical device number where the testreg
>> register
>> + * is located (or WB_SIO_DEV_NONE - don't select any
>> + * logical device)
>> + * @testreg: register number where the testbit bit is located
>> + * @testbit: index of a bit to check whether an actual
>> conflict exists
>> + * @warnonly: if set then a conflict isn't fatal (just warn
>> about it),
>> + * otherwise disable the particular GPIO port if a
>> conflict
>> + * is detected
>> + */
>> +struct winbond_gpio_port_conflict {
>> + const char *name;
>> + u8 dev;
>> + u8 testreg;
>> + u8 testbit;
>> + bool warnonly;
>> +};
>> +
>> +/**
>> + * struct winbond_gpio_info - information about a particular GPIO
>> port (device)
>> + * @dev: Super I/O logical device number of the
>> registers
>> + * specified below
>> + * @enablereg: port enable bit register number
>> + * @enablebit: index of a port enable bit
>> + * @outputreg: output driver mode bit register number
>> + * @outputppbit: index of a push-pull output driver mode bit
>> + * @ioreg: data direction register number
>> + * @invreg: pin data inversion register number
>> + * @datareg: pin data register number
>> + * @conflict: description of a device that possibly
>> conflicts with
>> + * this port
>> + */
>> +struct winbond_gpio_info {
>> + u8 dev;
>> + u8 enablereg;
>> + u8 enablebit;
>> + u8 outputreg;
>> + u8 outputppbit;
>> + u8 ioreg;
>> + u8 invreg;
>> + u8 datareg;
>> + struct winbond_gpio_port_conflict conflict;
>> +};
>> +
>> +static const struct winbond_gpio_info winbond_gpio_infos[6] = {
>> + { /* 0 */
>> + .dev = WB_SIO_DEV_GPIO12,
>> + .enablereg = WB_SIO_GPIO12_REG_ENABLE,
>> + .enablebit = WB_SIO_GPIO12_ENABLE_1,
>> + .outputreg = WB_SIO_REG_GPIO1_MF,
>> + .outputppbit = WB_SIO_REG_G1MF_G1PP,
>> + .ioreg = WB_SIO_GPIO12_REG_IO1,
>> + .invreg = WB_SIO_GPIO12_REG_INV1,
>> + .datareg = WB_SIO_GPIO12_REG_DATA1,
>> + .conflict = {
>> + .name = "UARTB",
>> + .dev = WB_SIO_DEV_UARTB,
>> + .testreg = WB_SIO_UARTB_REG_ENABLE,
>> + .testbit = WB_SIO_UARTB_ENABLE_ON,
>> + .warnonly = true
>> + }
>> + },
>> + { /* 1 */
>> + .dev = WB_SIO_DEV_GPIO12,
>> + .enablereg = WB_SIO_GPIO12_REG_ENABLE,
>> + .enablebit = WB_SIO_GPIO12_ENABLE_2,
>> + .outputreg = WB_SIO_REG_GPIO1_MF,
>> + .outputppbit = WB_SIO_REG_G1MF_G2PP,
>> + .ioreg = WB_SIO_GPIO12_REG_IO2,
>> + .invreg = WB_SIO_GPIO12_REG_INV2,
>> + .datareg = WB_SIO_GPIO12_REG_DATA2
>> + /* special conflict handling so doesn't use conflict
>> data */
>> + },
>> + { /* 2 */
>> + .dev = WB_SIO_DEV_GPIO34,
>> + .enablereg = WB_SIO_GPIO34_REG_ENABLE,
>> + .enablebit = WB_SIO_GPIO34_ENABLE_3,
>> + .outputreg = WB_SIO_REG_OVTGPIO3456,
>> + .outputppbit = WB_SIO_REG_OG3456_G3PP,
>> + .ioreg = WB_SIO_GPIO34_REG_IO3,
>> + .invreg = WB_SIO_GPIO34_REG_INV3,
>> + .datareg = WB_SIO_GPIO34_REG_DATA3,
>> + .conflict = {
>> + .name = "UARTC",
>> + .dev = WB_SIO_DEV_UARTC,
>> + .testreg = WB_SIO_UARTC_REG_ENABLE,
>> + .testbit = WB_SIO_UARTC_ENABLE_ON,
>> + .warnonly = true
>> + }
>> + },
>> + { /* 3 */
>> + .dev = WB_SIO_DEV_GPIO34,
>> + .enablereg = WB_SIO_GPIO34_REG_ENABLE,
>> + .enablebit = WB_SIO_GPIO34_ENABLE_4,
>> + .outputreg = WB_SIO_REG_OVTGPIO3456,
>> + .outputppbit = WB_SIO_REG_OG3456_G4PP,
>> + .ioreg = WB_SIO_GPIO34_REG_IO4,
>> + .invreg = WB_SIO_GPIO34_REG_INV4,
>> + .datareg = WB_SIO_GPIO34_REG_DATA4,
>> + .conflict = {
>> + .name = "UARTD",
>> + .dev = WB_SIO_DEV_UARTD,
>> + .testreg = WB_SIO_UARTD_REG_ENABLE,
>> + .testbit = WB_SIO_UARTD_ENABLE_ON,
>> + .warnonly = true
>> + }
>> + },
>> + { /* 4 */
>> + .dev = WB_SIO_DEV_WDGPIO56,
>> + .enablereg = WB_SIO_WDGPIO56_REG_ENABLE,
>> + .enablebit = WB_SIO_WDGPIO56_ENABLE_5,
>> + .outputreg = WB_SIO_REG_OVTGPIO3456,
>> + .outputppbit = WB_SIO_REG_OG3456_G5PP,
>> + .ioreg = WB_SIO_WDGPIO56_REG_IO5,
>> + .invreg = WB_SIO_WDGPIO56_REG_INV5,
>> + .datareg = WB_SIO_WDGPIO56_REG_DATA5,
>> + .conflict = {
>> + .name = "UARTE",
>> + .dev = WB_SIO_DEV_UARTE,
>> + .testreg = WB_SIO_UARTE_REG_ENABLE,
>> + .testbit = WB_SIO_UARTE_ENABLE_ON,
>> + .warnonly = true
>> + }
>> + },
>> + { /* 5 */
>> + .dev = WB_SIO_DEV_WDGPIO56,
>> + .enablereg = WB_SIO_WDGPIO56_REG_ENABLE,
>> + .enablebit = WB_SIO_WDGPIO56_ENABLE_6,
>> + .outputreg = WB_SIO_REG_OVTGPIO3456,
>> + .outputppbit = WB_SIO_REG_OG3456_G6PP,
>> + .ioreg = WB_SIO_WDGPIO56_REG_IO6,
>> + .invreg = WB_SIO_WDGPIO56_REG_INV6,
>> + .datareg = WB_SIO_WDGPIO56_REG_DATA6,
>> + .conflict = {
>> + .name = "FDC",
>> + .dev = WB_SIO_DEV_NONE,
>> + .testreg = WB_SIO_REG_GLOBAL_OPT,
>> + .testbit = WB_SIO_REG_GO_ENFDC,
>> + .warnonly = false
>> + }
>> + }
>> +};
>> +
>> +/* returns whether changing a pin is allowed */
>> +static bool winbond_gpio_get_info(unsigned int *gpio_num,
>> + const struct winbond_gpio_info
>> **info)
>> +{
>> + bool allow_changing = true;
>> + unsigned long i;
>> +
>> + for_each_set_bit(i, &gpios, BITS_PER_LONG) {
>> + if (*gpio_num < 8)
>> + break;
>> +
>> + *gpio_num -= 8;
>> + }
>> +
>> + *info = &winbond_gpio_infos[i];
>> +
>> + /*
>> + * GPIO2 (the second port) shares some pins with a basic PC
>> + * functionality, which is very likely controlled by the
>> firmware.
>> + * Don't allow changing these pins by default.
>> + */
>> + if (i == 1) {
>> + if (*gpio_num == 0 && !pledgpio)
>> + allow_changing = false;
>> + else if (*gpio_num == 1 && !beepgpio)
>> + allow_changing = false;
>> + else if ((*gpio_num == 5 || *gpio_num == 6) &&
>> !i2cgpio)
>> + allow_changing = false;
>> + }
>> +
>> + return allow_changing;
>> +}
>> +
>> +static int winbond_gpio_get(struct gpio_chip *gc, unsigned int
>> offset)
>> +{
>> + unsigned long *base = gpiochip_get_data(gc);
>> + const struct winbond_gpio_info *info;
>> + bool val;
>> +
>> + winbond_gpio_get_info(&offset, &info);
>> +
>> + val = winbond_sio_enter(*base);
>> + if (val)
>> + return val;
>> +
>> + winbond_sio_select_logical(*base, info->dev);
>> +
>> + val = winbond_sio_reg_btest(*base, info->datareg, offset);
>> + if (winbond_sio_reg_btest(*base, info->invreg, offset))
>> + val = !val;
>> +
>> + winbond_sio_leave(*base);
>> +
>> + return val;
>> +}
>> +
>> +static int winbond_gpio_direction_in(struct gpio_chip *gc, unsigned
>> int offset)
>> +{
>> + unsigned long *base = gpiochip_get_data(gc);
>> + const struct winbond_gpio_info *info;
>> + int ret;
>> +
>> + if (!winbond_gpio_get_info(&offset, &info))
>> + return -EACCES;
>> +
>> + ret = winbond_sio_enter(*base);
>> + if (ret)
>> + return ret;
>> +
>> + winbond_sio_select_logical(*base, info->dev);
>> +
>> + winbond_sio_reg_bset(*base, info->ioreg, offset);
>> +
>> + winbond_sio_leave(*base);
>> +
>> + return 0;
>> +}
>> +
>> +static int winbond_gpio_direction_out(struct gpio_chip *gc,
>> + unsigned int offset,
>> + int val)
>> +{
>> + unsigned long *base = gpiochip_get_data(gc);
>> + const struct winbond_gpio_info *info;
>> + int ret;
>> +
>> + if (!winbond_gpio_get_info(&offset, &info))
>> + return -EACCES;
>> +
>> + ret = winbond_sio_enter(*base);
>> + if (ret)
>> + return ret;
>> +
>> + winbond_sio_select_logical(*base, info->dev);
>> +
>> + winbond_sio_reg_bclear(*base, info->ioreg, offset);
>> +
>> + if (winbond_sio_reg_btest(*base, info->invreg, offset))
>> + val = !val;
>> +
>> + if (val)
>> + winbond_sio_reg_bset(*base, info->datareg, offset);
>> + else
>> + winbond_sio_reg_bclear(*base, info->datareg, offset);
>> +
>> + winbond_sio_leave(*base);
>> +
>> + return 0;
>> +}
>> +
>> +static void winbond_gpio_set(struct gpio_chip *gc, unsigned int
>> offset,
>> + int val)
>> +{
>> + unsigned long *base = gpiochip_get_data(gc);
>> + const struct winbond_gpio_info *info;
>> +
>> + if (!winbond_gpio_get_info(&offset, &info))
>> + return;
>> +
>> + if (winbond_sio_enter(*base) != 0)
>> + return;
>> +
>> + winbond_sio_select_logical(*base, info->dev);
>> +
>> + if (winbond_sio_reg_btest(*base, info->invreg, offset))
>> + val = !val;
>> +
>> + if (val)
>> + winbond_sio_reg_bset(*base, info->datareg, offset);
>> + else
>> + winbond_sio_reg_bclear(*base, info->datareg, offset);
>> +
>> + winbond_sio_leave(*base);
>> +}
>> +
>> +static struct gpio_chip winbond_gpio_chip = {
>> + .base = -1,
>> + .label = WB_GPIO_DRIVER_NAME,
>> + .owner = THIS_MODULE,
>> + .can_sleep = true,
>> + .get = winbond_gpio_get,
>> + .direction_input = winbond_gpio_direction_in,
>> + .set = winbond_gpio_set,
>> + .direction_output = winbond_gpio_direction_out,
>> +};
>> +
>> +static void winbond_gpio_configure_port0_pins(unsigned long base)
>> +{
>> + unsigned int val;
>> +
>> + val = winbond_sio_reg_read(base, WB_SIO_REG_GPIO1_MF);
>> + if ((val & WB_SIO_REG_G1MF_FS_MASK) ==
>> WB_SIO_REG_G1MF_FS_GPIO1)
>> + return;
>> +
>> + pr_warn("GPIO1 pins were connected to something else (%.2x),
>> fixing\n",
>> + val);
>> +
>> + val &= ~WB_SIO_REG_G1MF_FS_MASK;
>> + val |= WB_SIO_REG_G1MF_FS_GPIO1;
>> +
>> + winbond_sio_reg_write(base, WB_SIO_REG_GPIO1_MF, val);
>> +}
>> +
>> +static void winbond_gpio_configure_port1_check_i2c(unsigned long
>> base)
>> +{
>> + i2cgpio = !winbond_sio_reg_btest(base, WB_SIO_REG_I2C_PS,
>> + WB_SIO_REG_I2CPS_I2CFS);
>> + if (!i2cgpio)
>> + pr_warn("disabling GPIO2.5 and GPIO2.6 as I2C is
>> enabled\n");
>> +}
>> +
>> +static bool winbond_gpio_configure_port(unsigned long base, unsigned
>> int idx)
>> +{
>> + const struct winbond_gpio_info *info =
>> &winbond_gpio_infos[idx];
>> + const struct winbond_gpio_port_conflict *conflict = &info-
>>> conflict;
>> +
>> + /* is there a possible conflicting device defined? */
>> + if (conflict->name != NULL) {
>> + if (conflict->dev != WB_SIO_DEV_NONE)
>> + winbond_sio_select_logical(base, conflict-
>>> dev);
>> +
>> + if (winbond_sio_reg_btest(base, conflict->testreg,
>> + conflict->testbit)) {
>> + if (conflict->warnonly)
>> + pr_warn("enabled GPIO%u share pins
>> with active %s\n",
>> + idx + 1, conflict->name);
>> + else {
>> + pr_warn("disabling GPIO%u as %s is
>> enabled\n",
>> + idx + 1, conflict->name);
>> + return false;
>> + }
>> + }
>> + }
>> +
>> + /* GPIO1 and GPIO2 need some (additional) special handling */
>> + if (idx == 0)
>> + winbond_gpio_configure_port0_pins(base);
>> + else if (idx == 1)
>> + winbond_gpio_configure_port1_check_i2c(base);
>> +
>> + winbond_sio_select_logical(base, info->dev);
>> +
>> + winbond_sio_reg_bset(base, info->enablereg, info->enablebit);
>> +
>> + if (ppgpios & BIT(idx))
>> + winbond_sio_reg_bset(base, info->outputreg,
>> + info->outputppbit);
>> + else if (odgpios & BIT(idx))
>> + winbond_sio_reg_bclear(base, info->outputreg,
>> + info->outputppbit);
>> + else
>> + pr_notice("GPIO%u pins are %s\n", idx + 1,
>> + winbond_sio_reg_btest(base, info-
>>> outputreg,
>> + info->outputppbit) ?
>> + "push-pull" :
>> + "open drain");
>> +
>> + return true;
>> +}
>> +
>> +static int winbond_gpio_configure(unsigned long base)
>> +{
>> + unsigned long i;
>> +
>> + for_each_set_bit(i, &gpios, BITS_PER_LONG)
>> + if (!winbond_gpio_configure_port(base, i))
>
>> + gpios &= ~BIT(i);
>
> It might be __clear_bit(i, &gpios); as well.
>
>> +
>> + if (!gpios) {
>> + pr_err("please use 'gpios' module parameter to select
>> some active GPIO ports to enable\n");
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int winbond_gpio_check_chip(unsigned long base)
>> +{
>> + int ret;
>> + unsigned int chip;
>> +
>> + ret = winbond_sio_enter(base);
>> + if (ret)
>> + return ret;
>> +
>> + chip = winbond_sio_reg_read(base, WB_SIO_REG_CHIP_MSB) << 8;
>> + chip |= winbond_sio_reg_read(base, WB_SIO_REG_CHIP_LSB);
>> +
>> + pr_notice("chip ID at %lx is %.4x\n", base, chip);
>> +
>> + if ((chip & WB_SIO_CHIP_ID_W83627UHG_MASK) !=
>> + WB_SIO_CHIP_ID_W83627UHG) {
>> + pr_err("not an our chip\n");
>> + ret = -ENODEV;
>> + }
>> +
>> + winbond_sio_leave(base);
>> +
>> + return ret;
>> +}
>> +
>> +static int winbond_gpio_imatch(struct device *dev, unsigned int id)
>> +{
>> + unsigned long gpios_rem;
>> + int ret;
>> +
>> + gpios_rem = gpios & ~GENMASK(ARRAY_SIZE(winbond_gpio_infos) -
>> 1, 0);
>> + if (gpios_rem) {
>> + pr_warn("unknown ports (%lx) enabled in GPIO ports
>> bitmask\n",
>> + gpios_rem);
>> + gpios &= ~gpios_rem;
>> + }
>> +
>> + if (ppgpios & odgpios) {
>> + pr_err("some GPIO ports are set both to push-pull and
>> open drain mode at the same time\n");
>> + return 0;
>> + }
>> +
>> + if (baseparam != 0)
>> + return winbond_gpio_check_chip(baseparam) == 0;
>> +
>> + /*
>> + * if the 'base' module parameter is unset probe two chip
>> default
>> + * I/O port bases
>> + */
>> + baseparam = WB_SIO_BASE;
>> + ret = winbond_gpio_check_chip(baseparam);
>> + if (ret == 0)
>> + return 1;
>> + if (ret != -ENODEV && ret != -EBUSY)
>> + return 0;
>> +
>> + baseparam = WB_SIO_BASE_HIGH;
>> + return winbond_gpio_check_chip(baseparam) == 0;
>> +}
>> +
>> +static int winbond_gpio_iprobe(struct device *dev, unsigned int id)
>> +{
>> + int ret;
>> +
>> + if (baseparam == 0)
>> + return -EINVAL;
>> +
>> + ret = winbond_sio_enter(baseparam);
>> + if (ret)
>> + return ret;
>> +
>> + ret = winbond_gpio_configure(baseparam);
>> +
>> + winbond_sio_leave(baseparam);
>> +
>> + if (ret)
>> + return ret;
>> +
>> + /*
>> + * Add 8 gpios for every GPIO port that was enabled in gpios
>> + * module parameter (that wasn't disabled earlier in
>> + * winbond_gpio_configure() & co. due to, for example, a pin
>> conflict).
>> + */
>> + winbond_gpio_chip.ngpio = hweight_long(gpios) * 8;
>> +
>> + /*
>> + * GPIO6 port has only 5 pins, so if it is enabled we have to
>> adjust
>> + * the total count appropriately
>> + */
>> + if (gpios & BIT(5))
>> + winbond_gpio_chip.ngpio -= (8 - 5);
>> +
>> + winbond_gpio_chip.parent = dev;
>> +
>> + return devm_gpiochip_add_data(dev, &winbond_gpio_chip,
>> &baseparam);
>> +}
>> +
>> +static struct isa_driver winbond_gpio_idriver = {
>> + .driver = {
>> + .name = WB_GPIO_DRIVER_NAME,
>> + },
>> + .match = winbond_gpio_imatch,
>> + .probe = winbond_gpio_iprobe,
>> +};
>> +
>> +module_isa_driver(winbond_gpio_idriver, 1);
>> +
>> +module_param_named(base, baseparam, ulong, 0444);
>> +MODULE_PARM_DESC(base,
>> + "I/O port base (when unset - probe chip default
>> ones)");
>> +
>> +/* This parameter sets which GPIO devices (ports) we enable */
>> +module_param(gpios, ulong, 0444);
>> +MODULE_PARM_DESC(gpios,
>> + "bitmask of GPIO ports to enable (bit 0 - GPIO1, bit
>> 1 - GPIO2, etc.");
>> +
>> +/*
>> + * These two parameters below set how we configure GPIO ports output
>> drivers.
>> + * It can't be a one bitmask since we need three values per port:
>> push-pull,
>> + * open-drain and keep as-is (this is the default).
>> + */
>> +module_param(ppgpios, ulong, 0444);
>> +MODULE_PARM_DESC(ppgpios,
>> + "bitmask of GPIO ports to set to push-pull mode (bit
>> 0 - GPIO1, bit 1 - GPIO2, etc.");
>> +
>> +module_param(odgpios, ulong, 0444);
>> +MODULE_PARM_DESC(odgpios,
>> + "bitmask of GPIO ports to set to open drain mode
>> (bit 0 - GPIO1, bit 1 - GPIO2, etc.");
>> +
>> +/*
>> + * GPIO2.0 and GPIO2.1 control a basic PC functionality that we
>> + * don't allow tinkering with by default (it is very likely that the
>> + * firmware owns these pins).
>> + * These two parameters below allow overriding these prohibitions.
>> + */
>> +module_param(pledgpio, bool, 0644);
>> +MODULE_PARM_DESC(pledgpio,
>> + "enable changing value of GPIO2.0 bit (Power LED),
>> default no.");
>> +
>> +module_param(beepgpio, bool, 0644);
>> +MODULE_PARM_DESC(beepgpio,
>> + "enable changing value of GPIO2.1 bit (BEEP),
>> default no.");
>> +
>> +MODULE_AUTHOR("Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>");
>> +MODULE_DESCRIPTION("GPIO interface for Winbond Super I/O chips");
>> +MODULE_LICENSE("GPL");
>