diff options
Diffstat (limited to 'drivers/acorn/char/pcf8583.c')
| -rw-r--r-- | drivers/acorn/char/pcf8583.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/acorn/char/pcf8583.c b/drivers/acorn/char/pcf8583.c new file mode 100644 index 00000000000..ad7ae7ab892 --- /dev/null +++ b/drivers/acorn/char/pcf8583.c @@ -0,0 +1,239 @@ +/* + * linux/drivers/acorn/char/pcf8583.c + * + * Copyright (C) 2000 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Driver for PCF8583 RTC & RAM chip + */ +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/mc146818rtc.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/bcd.h> + +#include "pcf8583.h" + +static struct i2c_driver pcf8583_driver; + +static unsigned short ignore[] = { I2C_CLIENT_END }; +static unsigned short normal_addr[] = { 0x50, I2C_CLIENT_END }; + +static struct i2c_client_address_data addr_data = { + .normal_i2c = normal_addr, + .normal_i2c_range = ignore, + .probe = ignore, + .probe_range = ignore, + .ignore = ignore, + .ignore_range = ignore, + .force = ignore, +}; + +#define DAT(x) ((unsigned int)(x->dev.driver_data)) + +static int +pcf8583_attach(struct i2c_adapter *adap, int addr, int kind) +{ + struct i2c_client *c; + unsigned char buf[1], ad[1] = { 0 }; + struct i2c_msg msgs[2] = { + { addr, 0, 1, ad }, + { addr, I2C_M_RD, 1, buf } + }; + + c = kmalloc(sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + memset(c, 0, sizeof(*c)); + c->addr = addr; + c->adapter = adap; + c->driver = &pcf8583_driver; + + if (i2c_transfer(c->adapter, msgs, 2) == 2) + DAT(c) = buf[0]; + + return i2c_attach_client(c); +} + +static int +pcf8583_probe(struct i2c_adapter *adap) +{ + return i2c_probe(adap, &addr_data, pcf8583_attach); +} + +static int +pcf8583_detach(struct i2c_client *client) +{ + i2c_detach_client(client); + kfree(client); + return 0; +} + +static int +pcf8583_get_datetime(struct i2c_client *client, struct rtc_tm *dt) +{ + unsigned char buf[8], addr[1] = { 1 }; + struct i2c_msg msgs[2] = { + { client->addr, 0, 1, addr }, + { client->addr, I2C_M_RD, 6, buf } + }; + int ret = -EIO; + + memset(buf, 0, sizeof(buf)); + + ret = i2c_transfer(client->adapter, msgs, 2); + if (ret == 2) { + dt->year_off = buf[4] >> 6; + dt->wday = buf[5] >> 5; + + buf[4] &= 0x3f; + buf[5] &= 0x1f; + + dt->cs = BCD_TO_BIN(buf[0]); + dt->secs = BCD_TO_BIN(buf[1]); + dt->mins = BCD_TO_BIN(buf[2]); + dt->hours = BCD_TO_BIN(buf[3]); + dt->mday = BCD_TO_BIN(buf[4]); + dt->mon = BCD_TO_BIN(buf[5]); + + ret = 0; + } + + return ret; +} + +static int +pcf8583_set_datetime(struct i2c_client *client, struct rtc_tm *dt, int datetoo) +{ + unsigned char buf[8]; + int ret, len = 6; + + buf[0] = 0; + buf[1] = DAT(client) | 0x80; + buf[2] = BIN_TO_BCD(dt->cs); + buf[3] = BIN_TO_BCD(dt->secs); + buf[4] = BIN_TO_BCD(dt->mins); + buf[5] = BIN_TO_BCD(dt->hours); + + if (datetoo) { + len = 8; + buf[6] = BIN_TO_BCD(dt->mday) | (dt->year_off << 6); + buf[7] = BIN_TO_BCD(dt->mon) | (dt->wday << 5); + } + + ret = i2c_master_send(client, (char *)buf, len); + if (ret == len) + ret = 0; + + buf[1] = DAT(client); + i2c_master_send(client, (char *)buf, 2); + + return ret; +} + +static int +pcf8583_get_ctrl(struct i2c_client *client, unsigned char *ctrl) +{ + *ctrl = DAT(client); + return 0; +} + +static int +pcf8583_set_ctrl(struct i2c_client *client, unsigned char *ctrl) +{ + unsigned char buf[2]; + + buf[0] = 0; + buf[1] = *ctrl; + DAT(client) = *ctrl; + + return i2c_master_send(client, (char *)buf, 2); +} + +static int +pcf8583_read_mem(struct i2c_client *client, struct mem *mem) +{ + unsigned char addr[1]; + struct i2c_msg msgs[2] = { + { client->addr, 0, 1, addr }, + { client->addr, I2C_M_RD, 0, mem->data } + }; + + if (mem->loc < 8) + return -EINVAL; + + addr[0] = mem->loc; + msgs[1].len = mem->nr; + + return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO; +} + +static int +pcf8583_write_mem(struct i2c_client *client, struct mem *mem) +{ + unsigned char addr[1]; + struct i2c_msg msgs[2] = { + { client->addr, 0, 1, addr }, + { client->addr, 0, 0, mem->data } + }; + + if (mem->loc < 8) + return -EINVAL; + + addr[0] = mem->loc; + msgs[1].len = mem->nr; + + return i2c_transfer(client->adapter, msgs, 2) == 2 ? 0 : -EIO; +} + +static int +pcf8583_command(struct i2c_client *client, unsigned int cmd, void *arg) +{ + switch (cmd) { + case RTC_GETDATETIME: + return pcf8583_get_datetime(client, arg); + + case RTC_SETTIME: + return pcf8583_set_datetime(client, arg, 0); + + case RTC_SETDATETIME: + return pcf8583_set_datetime(client, arg, 1); + + case RTC_GETCTRL: + return pcf8583_get_ctrl(client, arg); + + case RTC_SETCTRL: + return pcf8583_set_ctrl(client, arg); + + case MEM_READ: + return pcf8583_read_mem(client, arg); + + case MEM_WRITE: + return pcf8583_write_mem(client, arg); + + default: + return -EINVAL; + } +} + +static struct i2c_driver pcf8583_driver = { + .name = "PCF8583", + .id = I2C_DRIVERID_PCF8583, + .flags = I2C_DF_NOTIFY, + .attach_adapter = pcf8583_probe, + .detach_client = pcf8583_detach, + .command = pcf8583_command +}; + +static __init int pcf8583_init(void) +{ + return i2c_add_driver(&pcf8583_driver); +} + +__initcall(pcf8583_init); |