Super I/O chips are ICs common to x86 that are used for interfacing to low-bandwidth peripherals. They often contain serial ports, watchdog timers and hardware monitoring units. They are usually addressable via one of two I/O port pairs, either 0x2e-0x2f or 0x4e-0x4f, but they don't typically respond to reads from their range unless a device-specific 'password' has been poked in. After this is done, they are read and written in the same manner however. On Linux, these devices aren't subject to any device/driver model. Each driver for some function (e.g. watchdog or GPIO) duplicates the device probe in the module_init and board-specific configuration is handled via module parameters. Lets do it a bit fancier in barebox and add a helper to register chips and a regmap for the control and configuration registers as well as a helper to register child devices for each function contained within the Super I/O chip. Board-specific configuration, e.g. which pin to use as a watchdog reset, can then be realized using barebox device-specific parameters. The regmap will be more of a debugging aid, however. For ease of porting from Linux, it's expected that access to the I/O ports won't happen via the regmap. For this reason, the new <superio.h> header offers functions to read/write these chips' registers as well. Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> --- drivers/mfd/Kconfig | 3 ++ drivers/mfd/Makefile | 1 + drivers/mfd/superio.c | 98 +++++++++++++++++++++++++++++++++++++++++++ include/superio.h | 64 ++++++++++++++++++++++++++++ 4 files changed, 166 insertions(+) create mode 100644 drivers/mfd/superio.c create mode 100644 include/superio.h diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 7d924cfca1eb..bd6f14a59f56 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -67,4 +67,7 @@ config MFD_STPMIC1 help Select this to support communication with the STPMIC1. +config MFD_SUPERIO + bool + endmenu diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 16a74abd77f3..690788eefb44 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -12,3 +12,4 @@ obj-$(CONFIG_MFD_TWL4030) += twl4030.o obj-$(CONFIG_MFD_TWL6030) += twl6030.o obj-$(CONFIG_RAVE_SP_CORE) += rave-sp.o obj-$(CONFIG_MFD_STPMIC1) += stpmic1.o +obj-$(CONFIG_MFD_SUPERIO) += superio.o diff --git a/drivers/mfd/superio.c b/drivers/mfd/superio.c new file mode 100644 index 000000000000..0f08d56cb357 --- /dev/null +++ b/drivers/mfd/superio.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Ahmad Fatoum, Pengutronix + */ + +#define pr_fmt(fmt) "superio: " fmt + +#include <common.h> +#include <superio.h> +#include <regmap.h> + +struct device_d *superio_func_add(struct superio_chip *siochip, const char *name) +{ + struct device_d *dev; + int ret; + + dev = device_alloc(name, DEVICE_ID_DYNAMIC); + dev->parent = siochip->dev; + + + ret = platform_device_register(dev); + if (ret) + return NULL; + + return dev; +} +EXPORT_SYMBOL(superio_func_add) + +static int superio_reg_read(void *ctx, unsigned int reg, unsigned int *val) +{ + struct superio_chip *siochip = ctx; + + siochip->enter(siochip->sioaddr); + + *val = superio_inb(siochip->sioaddr, reg); + + siochip->exit(siochip->sioaddr); + + return 0; +} + +static int superio_reg_write(void *ctx, unsigned int reg, unsigned int val) +{ + struct superio_chip *siochip = ctx; + + siochip->enter(siochip->sioaddr); + + superio_outb(siochip->sioaddr, reg, val); + + siochip->exit(siochip->sioaddr); + + return 0; +} + +static struct regmap_bus superio_regmap_bus = { + .reg_write = superio_reg_write, + .reg_read = superio_reg_read, +}; + +static struct regmap_config superio_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .reg_stride = 1, + .max_register = 0xff, +}; + +void superio_chip_add(struct superio_chip *siochip) +{ + struct regmap *regmap; + char *chipname; + char str[5]; + int ret; + + chipname = xasprintf("superio-%04x:%04x@%02x", + siochip->vid, siochip->devid, siochip->sioaddr); + siochip->dev = add_generic_device(chipname, DEVICE_ID_SINGLE, NULL, + siochip->sioaddr, 2, IORESOURCE_IO, + NULL); + + siochip->dev->priv = siochip; + + sprintf(str, "%04x", siochip->vid); + dev_add_param_fixed(siochip->dev, "vendor", str); + sprintf(str, "%04x", siochip->devid); + dev_add_param_fixed(siochip->dev, "device", str); + + regmap = regmap_init(siochip->dev, &superio_regmap_bus, siochip, + &superio_regmap_config); + if (IS_ERR(regmap)) + pr_warn("creating %s regmap failed: %s\n", + chipname, strerror(-PTR_ERR(regmap))); + + ret = regmap_register_cdev(regmap, chipname); + if (ret) + pr_warn("registering %s regmap cdev failed: %s\n", + chipname, strerror(-ret)); +} +EXPORT_SYMBOL(superio_chip_add) diff --git a/include/superio.h b/include/superio.h new file mode 100644 index 000000000000..12bff58b6b1b --- /dev/null +++ b/include/superio.h @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 Ahmad Fatoum, Pengutronix + */ + +#ifndef _SUPERIO_H_ +#define _SUPERIO_H_ + +#include <asm/io.h> +#include <linux/bitops.h> +#include <driver.h> +#include <linux/types.h> + +#define SIO_REG_DEVID 0x20 /* Device ID (2 bytes) */ +#define SIO_REG_DEVREV 0x22 /* Device revision */ +#define SIO_REG_MANID 0x23 /* Vendor ID (2 bytes) */ + +static inline u8 superio_inb(u16 base, u8 reg) +{ + outb(reg, base); + return inb(base + 1); +} + +static inline u16 superio_inw(u16 base, u8 reg) +{ + u16 val; + val = superio_inb(base, reg) << 8; + val |= superio_inb(base, reg + 1); + return val; +} + +static inline void superio_outb(u16 base, u8 reg, u8 val) +{ + outb(reg, base); + outb(val, base + 1); +} + +static inline void superio_set_bit(u16 base, u8 reg, unsigned bit) +{ + unsigned long val = superio_inb(base, reg); + __set_bit(bit, &val); + superio_outb(base, reg, val); +} + +static inline void superio_clear_bit(u16 base, u8 reg, unsigned bit) +{ + unsigned long val = superio_inb(base, reg); + __clear_bit(bit, &val); + superio_outb(base, reg, val); +} + +struct superio_chip { + struct device_d *dev; + u16 vid; + u16 devid; + u16 sioaddr; + void (*enter)(u16 sioaddr); + void (*exit)(u16 sioaddr); +}; + +void superio_chip_add(struct superio_chip *chip); +struct device_d *superio_func_add(struct superio_chip *chip, const char *name); + +#endif -- 2.23.0 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox