Commit c6f24f99 authored by Riku Voipio's avatar Riku Voipio Committed by Linus Torvalds
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[PATCH] rtc-rs5c372: change register reading method 



According to the datasheet rs5c372 supports three different methods for
reading register values.  Change from method #1 to method #3, since method #3
is the only one that works on Thecus N2100 board with this RTC.

Signed-off-by: default avatarRiku Voipio <riku.voipio@movial.fi>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent c5574768

drivers/rtc/rtc-rs5c372.c

+44 −40
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ 
#include <linux/rtc.h>

#include <linux/bcd.h>



#define DRV_VERSION "0.2"

#define DRV_VERSION "0.3"



/* Addresses to scan */

static unsigned short normal_i2c[] = { /* 0x32,*/ I2C_CLIENT_END };
@@ -39,6 +39,14 @@ static int rs5c372_attach(struct i2c_adapter *adapter); 
static int rs5c372_detach(struct i2c_client *client);

static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind);



struct rs5c372 {

	u8 reg_addr;

	u8 regs[17];

	struct i2c_msg msg[1];

	struct i2c_client client;

	struct rtc_device *rtc;

};



static struct i2c_driver rs5c372_driver = {

	.driver		= {

		.name	= "rs5c372",
@@ -49,18 +57,16 @@ static struct i2c_driver rs5c372_driver = { 


static int rs5c372_get_datetime(struct i2c_client *client, struct rtc_time *tm)

{

	unsigned char buf[7] = { RS5C372_REG_BASE };



	/* this implements the 1st reading method, according

	 * to the datasheet. buf[0] is initialized with

	 * address ptr and transmission format register.

	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);

	u8 *buf = &(rs5c372->regs[1]);



	/* this implements the 3rd reading method, according

	 * to the datasheet. rs5c372 defaults to internal

	 * address 0xF, so 0x0 is in regs[1]

	 */

	struct i2c_msg msgs[] = {

		{ client->addr, 0, 1, buf },

		{ client->addr, I2C_M_RD, 7, buf },

	};



	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {

	if ((i2c_transfer(client->adapter, rs5c372->msg, 1)) != 1) {

		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);

		return -EIO;

	}
@@ -114,23 +120,14 @@ static int rs5c372_set_datetime(struct i2c_client *client, struct rtc_time *tm) 


static int rs5c372_get_trim(struct i2c_client *client, int *osc, int *trim)

{

	unsigned char buf = RS5C372_REG_TRIM;



	struct i2c_msg msgs[] = {

		{ client->addr, 0, 1, &buf },

		{ client->addr, I2C_M_RD, 1, &buf },

	};



	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {

		dev_err(&client->dev, "%s: read error\n", __FUNCTION__);

		return -EIO;

	}

	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);

	u8 tmp = rs5c372->regs[RS5C372_REG_TRIM + 1];



	if (osc)

		*osc = (buf & RS5C372_TRIM_XSL) ? 32000 : 32768;

		*osc = (tmp & RS5C372_TRIM_XSL) ? 32000 : 32768;



	if (trim) {

		*trim = buf & RS5C372_TRIM_MASK;

		*trim = tmp & RS5C372_TRIM_MASK;

		dev_dbg(&client->dev, "%s: raw trim=%x\n", __FUNCTION__, *trim);

	}
@@ -201,7 +198,7 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind) 
{

	int err = 0;

	struct i2c_client *client;

	struct rtc_device *rtc;

	struct rs5c372 *rs5c372;



	dev_dbg(&adapter->dev, "%s\n", __FUNCTION__);
@@ -210,10 +207,11 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind) 
		goto exit;

	}



	if (!(client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL))) {

	if (!(rs5c372 = kzalloc(sizeof(struct rs5c372), GFP_KERNEL))) {

		err = -ENOMEM;

		goto exit;

	}

	client = &rs5c372->client;



	/* I2C client */

	client->addr = address;
@@ -222,26 +220,33 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind) 


	strlcpy(client->name, rs5c372_driver.driver.name, I2C_NAME_SIZE);



	i2c_set_clientdata(client, rs5c372);



	rs5c372->msg[0].addr = address;

	rs5c372->msg[0].flags = I2C_M_RD;

	rs5c372->msg[0].len = sizeof(rs5c372->regs);

	rs5c372->msg[0].buf = rs5c372->regs;



	/* Inform the i2c layer */

	if ((err = i2c_attach_client(client)))

		goto exit_kfree;



	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");



	rtc = rtc_device_register(rs5c372_driver.driver.name, &client->dev,

				&rs5c372_rtc_ops, THIS_MODULE);

	rs5c372->rtc = rtc_device_register(rs5c372_driver.driver.name,

				&client->dev, &rs5c372_rtc_ops, THIS_MODULE);



	if (IS_ERR(rtc)) {

		err = PTR_ERR(rtc);

	if (IS_ERR(rs5c372->rtc)) {

		err = PTR_ERR(rs5c372->rtc);

		goto exit_detach;

	}



	i2c_set_clientdata(client, rtc);



	err = device_create_file(&client->dev, &dev_attr_trim);

	if (err) goto exit_devreg;

	if (err)

		goto exit_devreg;

	err = device_create_file(&client->dev, &dev_attr_osc);

	if (err) goto exit_trim;

	if (err)

		goto exit_trim;



	return 0;
@@ -249,13 +254,13 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind) 
	device_remove_file(&client->dev, &dev_attr_trim);



exit_devreg:

	rtc_device_unregister(rtc);

	rtc_device_unregister(rs5c372->rtc);



exit_detach:

	i2c_detach_client(client);



exit_kfree:

	kfree(client);

	kfree(rs5c372);



exit:

	return err;
@@ -264,16 +269,15 @@ static int rs5c372_probe(struct i2c_adapter *adapter, int address, int kind) 
static int rs5c372_detach(struct i2c_client *client)

{

	int err;

	struct rtc_device *rtc = i2c_get_clientdata(client);

	struct rs5c372 *rs5c372 = i2c_get_clientdata(client);



	if (rtc)

		rtc_device_unregister(rtc);

	if (rs5c372->rtc)

		rtc_device_unregister(rs5c372->rtc);



	if ((err = i2c_detach_client(client)))

		return err;



	kfree(client);



	kfree(rs5c372);

	return 0;

}