path: root/drivers/rtc/rtc-isl1208.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Intersil ISL1208 rtc class driver
 *
 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org>
 */

#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/rtc.h>

/* Register map */
/* rtc section */
#define ISL1208_REG_SC  0x00
#define ISL1208_REG_MN  0x01
#define ISL1208_REG_HR  0x02
#define ISL1208_REG_HR_MIL     (1<<7)	/* 24h/12h mode */
#define ISL1208_REG_HR_PM      (1<<5)	/* PM/AM bit in 12h mode */
#define ISL1208_REG_DT  0x03
#define ISL1208_REG_MO  0x04
#define ISL1208_REG_YR  0x05
#define ISL1208_REG_DW  0x06
#define ISL1208_RTC_SECTION_LEN 7

/* control/status section */
#define ISL1208_REG_SR  0x07
#define ISL1208_REG_SR_ARST    (1<<7)	/* auto reset */
#define ISL1208_REG_SR_XTOSCB  (1<<6)	/* crystal oscillator */
#define ISL1208_REG_SR_WRTC    (1<<4)	/* write rtc */
#define ISL1208_REG_SR_EVT     (1<<3)	/* event */
#define ISL1208_REG_SR_ALM     (1<<2)	/* alarm */
#define ISL1208_REG_SR_BAT     (1<<1)	/* battery */
#define ISL1208_REG_SR_RTCF    (1<<0)	/* rtc fail */
#define ISL1208_REG_INT 0x08
#define ISL1208_REG_INT_ALME   (1<<6)   /* alarm enable */
#define ISL1208_REG_INT_IM     (1<<7)   /* interrupt/alarm mode */
#define ISL1219_REG_EV  0x09
#define ISL1219_REG_EV_EVEN    (1<<4)   /* event detection enable */
#define ISL1219_REG_EV_EVIENB  (1<<7)   /* event in pull-up disable */
#define ISL1208_REG_ATR 0x0a
#define ISL1208_REG_DTR 0x0b

/* alarm section */
#define ISL1208_REG_SCA 0x0c
#define ISL1208_REG_MNA 0x0d
#define ISL1208_REG_HRA 0x0e
#define ISL1208_REG_DTA 0x0f
#define ISL1208_REG_MOA 0x10
#define ISL1208_REG_DWA 0x11
#define ISL1208_ALARM_SECTION_LEN 6

/* user section */
#define ISL1208_REG_USR1 0x12
#define ISL1208_REG_USR2 0x13
#define ISL1208_USR_SECTION_LEN 2

/* event section */
#define ISL1219_REG_SCT 0x14
#define ISL1219_REG_MNT 0x15
#define ISL1219_REG_HRT 0x16
#define ISL1219_REG_DTT 0x17
#define ISL1219_REG_MOT 0x18
#define ISL1219_REG_YRT 0x19
#define ISL1219_EVT_SECTION_LEN 6

static struct i2c_driver isl1208_driver;

/* Chip capabilities table */
struct isl1208_config {
	unsigned int	nvmem_length;
	unsigned	has_tamper:1;
	unsigned	has_timestamp:1;
	unsigned	has_inverted_osc_bit:1;
};

static const struct isl1208_config config_isl1208 = {
	.nvmem_length = 2,
	.has_tamper = false,
	.has_timestamp = false
};

static const struct isl1208_config config_isl1209 = {
	.nvmem_length = 2,
	.has_tamper = true,
	.has_timestamp = false
};

static const struct isl1208_config config_isl1218 = {
	.nvmem_length = 8,
	.has_tamper = false,
	.has_timestamp = false
};

static const struct isl1208_config config_isl1219 = {
	.nvmem_length = 2,
	.has_tamper = true,
	.has_timestamp = true
};

static const struct isl1208_config config_raa215300_a0 = {
	.nvmem_length = 2,
	.has_tamper = false,
	.has_timestamp = false,
	.has_inverted_osc_bit = true
};

static const struct i2c_device_id isl1208_id[] = {
	{ "isl1208", .driver_data = (kernel_ulong_t)&config_isl1208 },
	{ "isl1209", .driver_data = (kernel_ulong_t)&config_isl1209 },
	{ "isl1218", .driver_data = (kernel_ulong_t)&config_isl1218 },
	{ "isl1219", .driver_data = (kernel_ulong_t)&config_isl1219 },
	{ "raa215300_a0", .driver_data = (kernel_ulong_t)&config_raa215300_a0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, isl1208_id);

static const __maybe_unused struct of_device_id isl1208_of_match[] = {
	{ .compatible = "isil,isl1208", .data = &config_isl1208 },
	{ .compatible = "isil,isl1209", .data = &config_isl1209 },
	{ .compatible = "isil,isl1218", .data = &config_isl1218 },
	{ .compatible = "isil,isl1219", .data = &config_isl1219 },
	{ }
};
MODULE_DEVICE_TABLE(of, isl1208_of_match);

/* Device state */
struct isl1208_state {
	struct nvmem_config nvmem_config;
	struct rtc_device *rtc;
	const struct isl1208_config *config;
};

/* block read */
static int
isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[],
		      unsigned len)
{
	int ret;

	WARN_ON(reg > ISL1219_REG_YRT);
	WARN_ON(reg + len > ISL1219_REG_YRT + 1);

	ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf);
	return (ret < 0) ? ret : 0;
}

/* block write */
static int
isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[],
		     unsigned len)
{
	int ret;

	WARN_ON(reg > ISL1219_REG_YRT);
	WARN_ON(reg + len > ISL1219_REG_YRT + 1);

	ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf);
	return (ret < 0) ? ret