/* SPDX-License-Identifier: GPL-2.0 */
/*
* CZ.NIC's Turris Omnia MCU driver
*
* 2024 by Marek Behún <kabel@kernel.org>
*/
#ifndef __TURRIS_OMNIA_MCU_H
#define __TURRIS_OMNIA_MCU_H
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/gpio/driver.h>
#include <linux/hw_random.h>
#include <linux/if_ether.h>
#include <linux/mutex.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include <linux/workqueue.h>
#include <asm/byteorder.h>
#include <linux/unaligned.h>
struct i2c_client;
struct rtc_device;
/**
* struct omnia_mcu - driver private data structure
* @client: I2C client
* @type: MCU type (STM32, GD32, MKL, or unknown)
* @features: bitmap of features supported by the MCU firmware
* @board_serial_number: board serial number, if stored in MCU
* @board_first_mac: board first MAC address, if stored in MCU
* @board_revision: board revision, if stored in MCU
* @gc: GPIO chip
* @lock: mutex to protect internal GPIO chip state
* @mask: bitmap of masked IRQs
* @rising: bitmap of rising edge IRQs
* @falling: bitmap of falling edge IRQs
* @both: bitmap of both edges IRQs
* @cached: bitmap of cached IRQ line values (when an IRQ line is configured for
* both edges, we cache the corresponding GPIO values in the IRQ
* handler)
* @is_cached: bitmap of which IRQ line values are cached
* @button_release_emul_work: front button release emulation work, used with old MCU firmware
* versions which did not send button release events, only button press
* events
* @last_status: cached value of the status word, to be compared with new value to
* determine which interrupt events occurred, used with old MCU
* firmware versions which only informed that the status word changed,
* but not which bits of the status word changed
* @button_pressed_emul: the front button is still emulated to be pressed
* @rtcdev: RTC device, does not actually count real-time, the device is only
* used for the RTC alarm mechanism, so that the board can be
* configured to wake up from poweroff state at a specific time
* @rtc_alarm: RTC alarm that was set for the board to wake up on, in MCU time
* (seconds since last MCU reset)
* @front_button_poweron: the front button should power on the device after it is powered off
* @wdt: watchdog driver structure
* @trng: RNG driver structure
* @trng_entropy_ready: RNG entropy ready completion
*/
struct omnia_mcu {
struct i2c_client *client;
const char *type;
u32 features;
u64 board_serial_number;
u8 board_first_mac[ETH_ALEN];
u8 board_revision;
#ifdef CONFIG_TURRIS_OMNIA_MCU_GPIO
struct gpio_chip gc;
struct mutex lock;
unsigned long mask, rising, falling, both, cached, is_cached;
struct delayed_work button_release_emul_work;
unsigned long last_status;
bool button_pressed_emul;
#endif
#ifdef CONFIG_TURRIS_OMNIA_MCU_SYSOFF_WAKEUP
struct rtc_device *rtcdev;
u32 rtc_alarm;
bool front_button_poweron;
#endif
#ifdef CONFIG_TURRIS_OMNIA_MCU_WATCHDOG
struct watchdog_device wdt;
#endif
#ifdef CONFIG_TURRIS_OMNIA_MCU_TRNG
struct hwrng trng;
struct completion trng_entropy_ready;
#endif
};
int omnia_cmd_write_read(const struct i2c_client *client,
void *cmd, unsigned int cmd_len,
void *reply, unsigned int reply_len);
static inline int omnia_cmd_write(const struct i2c_client *client, void *cmd,
unsigned int len)
{
return omnia_cmd_write_read(client, cmd, len, NULL, 0);
}
static inline int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd,
u8 val)
{
u8 buf[2] = { cmd, val };
return omnia_cmd_write(client, buf, sizeof(buf));
}
static inline int omnia_cmd_write_u16(const struct i2c_client *client, u8 cmd,
u16 val)
{
u8 buf[3];
buf[0] = cmd;
put_unaligned_le16(val, &buf[1]);
return omnia_cmd_write(client, buf, sizeof(buf));
}
static inline int omnia_cmd_write_u32(const struct i2c_client *client, u8 cmd,
u32 val)
{
u8 buf[5];
buf[0] = cmd;
put_unaligned_le32(val, &buf[1]);
return omnia_cmd_write(client, buf, sizeof(buf));
}
static inline int omnia_cmd_read(const struct i2c_client *client, u8 cmd,
void *reply, unsigned int len)
{
return omnia_cmd_write_read(client, &cmd, 1, reply, len);
}
static inline unsigned int
omnia_compute_reply_length(unsigned long mask, bool interleaved,
unsigned int offset)
{
if (!mask)
return 0;
return ((__fls(mask) >> 3) << interleaved) + 1 + offset;
}
/* Returns 0 on success */
static inline int omnia_cmd_read_bits(const struct i2c_client *client, u8 cmd,
unsigned long bits, unsigned long *dst)
{
__le32 reply;
int err;
if (!bits) {
*dst = 0;
return 0;
}
err = omnia_cmd_read(client, cmd, &reply,
omnia_compute_reply_length(bits, false, 0));
if (err)
return err;
*dst = le32_to_cpu(reply) & bits;
return 0;
}
static inline int omnia_cmd_read_bit(const struct i2c_client *client, u8 cmd,
unsigned long bit)
{
unsigned long reply;
int err;
err = omnia_cmd_read_bits(client, cmd, bit, &reply);
if (err)
return err;
return !!reply;
}
static inline int omnia_cmd_read_u32(const struct i2c_client *client, u8 cmd,
u32 *dst)
{
__le32 reply;
int err;
err = omnia_cmd_read(client, cmd, &reply, sizeof(reply));
if (err)
return err;
*dst = le32_to_cpu(reply);
return 0;
}
static inline int omnia_cmd_read_u16(const struct i2c_client *client, u8 cmd,
u16 *dst)
{
__le16 reply;
int err;
err = omnia_cmd_read(client, cmd, &reply, sizeof(reply));
if (err)
return err;
*dst = le16_to_cpu(reply);
return 0;
}
static inline int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd,
u8 *reply)
{
return omnia_cmd_read(client, cmd, reply, sizeof(*reply));
}
#ifdef CONFIG_TURRIS_OMNIA_MCU_GPIO
extern const u8 omnia_int_to_gpio_idx[32];
extern const struct attribute_group omnia_mcu_gpio_group;
int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu);
#else
static inline int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu)
{
return 0;
}
#endif
#ifdef CONFIG_TURRIS_OMNIA_MCU_SYSOFF_WAKEUP
extern const struct attribute_group omnia_mcu_poweroff_group;
int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu);
#else
static inline int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu)
{
return 0;
}
#endif
#ifdef CONFIG_TURRIS_OMNIA_MCU_TRNG
int omnia_mcu_register_trng(struct omnia_mcu *mcu);
#else
static inline int omnia_mcu_register_trng(struct omnia_mcu *mcu)
{
return 0;
}
#endif
#ifdef CONFIG_TURRIS_OMNIA_MCU_WATCHDOG
int omnia_mcu_register_watchdog(struct omnia_mcu *mcu);
#else
static inline int omnia_mcu_register_watchdog(struct omnia_mcu *mcu)
{
return 0;
}
#endif
#endif /* __TURRIS_OMNIA_MCU_H */
