From c065f35c17929067a367139d14e26897d60c7f6d Mon Sep 17 00:00:00 2001 From: David Brownell Date: Tue, 17 Jul 2007 04:05:10 -0700 Subject: [PATCH] rtc-ds1307 becomes new-style i2c driver Convert the rtc-ds1307 driver into a "new style" driver. Also improve probe() checks: be more correct about switching out of AM/PM mode, and issue a (debug) diagnostic when failing due to bogus register values. Signed-off-by: David Brownell Cc: Andrew Victor Cc: Bill Gatliff Cc: Alessandro Zummo Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Kumar Gala Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-ds1307.c | 128 ++++++++++++++++----------------------- 1 file changed, 53 insertions(+), 75 deletions(-) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 5306a1a5b873..5158a625671f 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -27,13 +27,8 @@ * This is currently a simple no-alarms driver. If your board has the * alarm irq wired up on a ds1337 or ds1339, and you want to use that, * then look at the rtc-rs5c372 driver for code to steal... - * - * If the I2C "force" mechanism is used, we assume the chip is a ds1337. - * (Much better would be board-specific tables of I2C devices, along with - * the platform_data drivers would use to sort such issues out.) */ enum ds_type { - unknown = 0, ds_1307, ds_1337, ds_1338, @@ -43,11 +38,6 @@ enum ds_type { // rs5c372 too? different address... }; -static unsigned short normal_i2c[] = { 0x68, I2C_CLIENT_END }; - -I2C_CLIENT_INSMOD; - - /* RTC registers don't differ much, except for the century flag */ #define DS1307_REG_SECS 0x00 /* 00-59 */ @@ -55,6 +45,8 @@ I2C_CLIENT_INSMOD; # define DS1340_BIT_nEOSC 0x80 #define DS1307_REG_MIN 0x01 /* 00-59 */ #define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */ +# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */ +# define DS1307_BIT_PM 0x20 /* in REG_HOUR */ # define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */ # define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */ #define DS1307_REG_WDAY 0x03 /* 01-07 */ @@ -252,39 +244,27 @@ static const struct rtc_class_ops ds13xx_rtc_ops = { static struct i2c_driver ds1307_driver; -static int __devinit -ds1307_detect(struct i2c_adapter *adapter, int address, int kind) +static int __devinit ds1307_probe(struct i2c_client *client) { struct ds1307 *ds1307; int err = -ENODEV; - struct i2c_client *client; int tmp; const struct chip_desc *chip; + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); - if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) { - err = -ENOMEM; - goto exit; + chip = find_chip(client->name); + if (!chip) { + dev_err(&client->dev, "unknown chip type '%s'\n", + client->name); + return -ENODEV; } - /* REVISIT: pending driver model conversion, set up "client" - * ourselves, and use a hack to determine the RTC type (instead - * of reading the client->name we're given) - */ - client = &ds1307->dev; - client->addr = address; - client->adapter = adapter; - client->driver = &ds1307_driver; - - /* HACK: "force" implies "needs ds1337-style-oscillator setup", and - * that's the only kind of chip setup we'll know about. Until the - * driver model conversion, here's where to add any board-specific - * code to say what kind of chip is present... - */ - if (kind >= 0) - chip = find_chip("ds1337"); - else - chip = find_chip("ds1307"); - strlcpy(client->name, chip->name, I2C_NAME_SIZE); + if (!i2c_check_functionality(adapter, + I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) + return -EIO; + + if (!(ds1307 = kzalloc(sizeof(struct ds1307), GFP_KERNEL))) + return -ENOMEM; ds1307->client = client; i2c_set_clientdata(client, ds1307); @@ -378,94 +358,92 @@ read_rtc: goto read_rtc; } break; - default: + case ds_1337: + case ds_1339: break; } tmp = ds1307->regs[DS1307_REG_SECS]; tmp = BCD2BIN(tmp & 0x7f); if (tmp > 60) - goto exit_free; + goto exit_bad; tmp = BCD2BIN(ds1307->regs[DS1307_REG_MIN] & 0x7f); if (tmp > 60) - goto exit_free; + goto exit_bad; tmp = BCD2BIN(ds1307->regs[DS1307_REG_MDAY] & 0x3f); if (tmp == 0 || tmp > 31) - goto exit_free; + goto exit_bad; tmp = BCD2BIN(ds1307->regs[DS1307_REG_MONTH] & 0x1f); if (tmp == 0 || tmp > 12) - goto exit_free; + goto exit_bad; - /* force into in 24 hour mode (most chips) or - * disable century bit (ds1340) - * - * REVISIT forcing 24 hour mode can prevent multi-master - * configs from sharing this RTC ... don't do this. - * The clock needs to be reset after changing it, too... - */ tmp = ds1307->regs[DS1307_REG_HOUR]; - if (tmp & (1 << 6)) { - if (tmp & (1 << 5)) - tmp = BCD2BIN(tmp & 0x1f) + 12; - else - tmp = BCD2BIN(tmp); + switch (ds1307->type) { + case ds_1340: + case m41t00: + /* NOTE: ignores century bits; fix before deploying + * systems that will run through year 2100. + */ + break; + default: + if (!(tmp & DS1307_BIT_12HR)) + break; + + /* Be sure we're in 24 hour mode. Multi-master systems + * take note... + */ + tmp = BCD2BIN(tmp & 0x1f); + if (tmp == 12) + tmp = 0; + if (ds1307->regs[DS1307_REG_HOUR] & DS1307_BIT_PM) + tmp += 12; i2c_smbus_write_byte_data(client, DS1307_REG_HOUR, BIN2BCD(tmp)); } - /* Tell the I2C layer a new client has arrived */ - if ((err = i2c_attach_client(client))) - goto exit_free; - ds1307->rtc = rtc_device_register(client->name, &client->dev, &ds13xx_rtc_ops, THIS_MODULE); if (IS_ERR(ds1307->rtc)) { err = PTR_ERR(ds1307->rtc); dev_err(&client->dev, "unable to register the class device\n"); - goto exit_detach; + goto exit_free; } return 0; -exit_detach: - i2c_detach_client(client); +exit_bad: + dev_dbg(&client->dev, "%s: %02x %02x %02x %02x %02x %02x %02x\n", + "bogus register", + ds1307->regs[0], ds1307->regs[1], + ds1307->regs[2], ds1307->regs[3], + ds1307->regs[4], ds1307->regs[5], + ds1307->regs[6]); + exit_free: kfree(ds1307); -exit: return err; } -static int __devinit -ds1307_attach_adapter(struct i2c_adapter *adapter) -{ - if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) - return 0; - return i2c_probe(adapter, &addr_data, ds1307_detect); -} - -static int __devexit ds1307_detach_client(struct i2c_client *client) +static int __devexit ds1307_remove(struct i2c_client *client) { - int err; struct ds1307 *ds1307 = i2c_get_clientdata(client); rtc_device_unregister(ds1307->rtc); - if ((err = i2c_detach_client(client))) - return err; kfree(ds1307); return 0; } static struct i2c_driver ds1307_driver = { .driver = { - .name = "ds1307", + .name = "rtc-ds1307", .owner = THIS_MODULE, }, - .attach_adapter = ds1307_attach_adapter, - .detach_client = __devexit_p(ds1307_detach_client), + .probe = ds1307_probe, + .remove = __devexit_p(ds1307_remove), }; static int __init ds1307_init(void) -- 2.34.1