power: supply: ds2760_battery: merge ds2760 supply driver with its w1 slave companion

This patch removes the w1 slave driver that used to register the w1 family
and instanciate a platform device at runtime. The code now lives in the
supply driver instead to avoid that level of indirection.

The old device name "ds2760-battery.0" is preserved, so userspace
applications can access the same virtual device nodes as before.

Note that because the w1 core does not currently have a framework for
suspend/resume, the driver now registers a PM notifier callback.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>

2 files changed, 232 insertions, 91 deletions

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 428b426842f4..518a88c4adfa 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -92,7 +92,7 @@ config BATTERY_CPCAP
 
 config BATTERY_DS2760
 	tristate "DS2760 battery driver (HP iPAQ & others)"
-	depends on W1 && W1_SLAVE_DS2760
+	depends on W1
 	help
 	  Say Y here to enable support for batteries with ds2760 chip.
 
diff --git a/drivers/power/supply/ds2760_battery.c b/drivers/power/supply/ds2760_battery.c
index ae180dc929c9..aa406a7c65a1 100644
--- a/drivers/power/supply/ds2760_battery.c
+++ b/drivers/power/supply/ds2760_battery.c
@@ -27,9 +27,63 @@
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/power_supply.h>
-
+#include <linux/suspend.h>
 #include <linux/w1.h>
-#include "../../w1/slaves/w1_ds2760.h"
+
+static unsigned int cache_time = 1000;
+module_param(cache_time, uint, 0644);
+MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
+
+static bool pmod_enabled;
+module_param(pmod_enabled, bool, 0644);
+MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
+
+static unsigned int rated_capacity;
+module_param(rated_capacity, uint, 0644);
+MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
+
+static unsigned int current_accum;
+module_param(current_accum, uint, 0644);
+MODULE_PARM_DESC(current_accum, "current accumulator value");
+
+#define W1_FAMILY_DS2760		0x30
+
+/* Known commands to the DS2760 chip */
+#define W1_DS2760_SWAP			0xAA
+#define W1_DS2760_READ_DATA		0x69
+#define W1_DS2760_WRITE_DATA		0x6C
+#define W1_DS2760_COPY_DATA		0x48
+#define W1_DS2760_RECALL_DATA		0xB8
+#define W1_DS2760_LOCK			0x6A
+
+/* Number of valid register addresses */
+#define DS2760_DATA_SIZE		0x40
+
+#define DS2760_PROTECTION_REG		0x00
+
+#define DS2760_STATUS_REG		0x01
+#define DS2760_STATUS_IE		(1 << 2)
+#define DS2760_STATUS_SWEN		(1 << 3)
+#define DS2760_STATUS_RNAOP		(1 << 4)
+#define DS2760_STATUS_PMOD		(1 << 5)
+
+#define DS2760_EEPROM_REG		0x07
+#define DS2760_SPECIAL_FEATURE_REG	0x08
+#define DS2760_VOLTAGE_MSB		0x0c
+#define DS2760_VOLTAGE_LSB		0x0d
+#define DS2760_CURRENT_MSB		0x0e
+#define DS2760_CURRENT_LSB		0x0f
+#define DS2760_CURRENT_ACCUM_MSB	0x10
+#define DS2760_CURRENT_ACCUM_LSB	0x11
+#define DS2760_TEMP_MSB			0x18
+#define DS2760_TEMP_LSB			0x19
+#define DS2760_EEPROM_BLOCK0		0x20
+#define DS2760_ACTIVE_FULL		0x20
+#define DS2760_EEPROM_BLOCK1		0x30
+#define DS2760_STATUS_WRITE_REG		0x31
+#define DS2760_RATED_CAPACITY		0x32
+#define DS2760_CURRENT_OFFSET_BIAS	0x33
+#define DS2760_ACTIVE_EMPTY		0x3b
 
 struct ds2760_device_info {
 	struct device *dev;
@@ -55,28 +109,113 @@ struct ds2760_device_info {
 	int full_counter;
 	struct power_supply *bat;
 	struct power_supply_desc bat_desc;
-	struct device *w1_dev;
 	struct workqueue_struct *monitor_wqueue;
 	struct delayed_work monitor_work;
 	struct delayed_work set_charged_work;
+	struct notifier_block pm_notifier;
 };
 
-static unsigned int cache_time = 1000;
-module_param(cache_time, uint, 0644);
-MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
+static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
+			int io)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
 
-static bool pmod_enabled;
-module_param(pmod_enabled, bool, 0644);
-MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
+	if (!dev)
+		return 0;
 
-static unsigned int rated_capacity;
-module_param(rated_capacity, uint, 0644);
-MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
+	mutex_lock(&sl->master->bus_mutex);
 
-static unsigned int current_accum;
-module_param(current_accum, uint, 0644);
-MODULE_PARM_DESC(current_accum, "current accumulator value");
+	if (addr > DS2760_DATA_SIZE || addr < 0) {
+		count = 0;
+		goto out;
+	}
+	if (addr + count > DS2760_DATA_SIZE)
+		count = DS2760_DATA_SIZE - addr;
+
+	if (!w1_reset_select_slave(sl)) {
+		if (!io) {
+			w1_write_8(sl->master, W1_DS2760_READ_DATA);
+			w1_write_8(sl->master, addr);
+			count = w1_read_block(sl->master, buf, count);
+		} else {
+			w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
+			w1_write_8(sl->master, addr);
+			w1_write_block(sl->master, buf, count);
+			/* XXX w1_write_block returns void, not n_written */
+		}
+	}
+
+out:
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return count;
+}
+
+static int w1_ds2760_read(struct device *dev,
+			  char *buf, int addr,
+			  size_t count)
+{
+	return w1_ds2760_io(dev, buf, addr, count, 0);
+}
+
+static int w1_ds2760_write(struct device *dev,
+			   char *buf,
+			   int addr, size_t count)
+{
+	return w1_ds2760_io(dev, buf, addr, count, 1);
+}
 
+static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+
+	if (w1_reset_select_slave(sl) == 0) {
+		w1_write_8(sl->master, cmd);
+		w1_write_8(sl->master, addr);
+	}
+
+	mutex_unlock(&sl->master->bus_mutex);
+	return 0;
+}
+
+static int w1_ds2760_store_eeprom(struct device *dev, int addr)
+{
+	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
+}
+
+static int w1_ds2760_recall_eeprom(struct device *dev, int addr)
+{
+	return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
+}
+
+static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
+			     struct bin_attribute *bin_attr, char *buf,
+			     loff_t off, size_t count)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	return w1_ds2760_read(dev, buf, off, count);
+}
+
+static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
+
+static struct bin_attribute *w1_ds2760_bin_attrs[] = {
+	&bin_attr_w1_slave,
+	NULL,
+};
+
+static const struct attribute_group w1_ds2760_group = {
+	.bin_attrs = w1_ds2760_bin_attrs,
+};
+
+static const struct attribute_group *w1_ds2760_groups[] = {
+	&w1_ds2760_group,
+	NULL,
+};
 /* Some batteries have their rated capacity stored a N * 10 mAh, while
  * others use an index into this table. */
 static int rated_capacities[] = {
@@ -138,10 +277,10 @@ static int ds2760_battery_read_status(struct ds2760_device_info *di)
 		count = DS2760_TEMP_LSB - start + 1;
 	}
 
-	ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
+	ret = w1_ds2760_read(di->dev, di->raw + start, start, count);
 	if (ret != count) {
 		dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
-			 di->w1_dev);
+			 di->dev);
 		return 1;
 	}
 
@@ -242,7 +381,7 @@ static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
 	acr[0] = acr_val >> 8;
 	acr[1] = acr_val & 0xff;
 
-	if (w1_ds2760_write(di->w1_dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
+	if (w1_ds2760_write(di->dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
 		dev_warn(di->dev, "ACR write failed\n");
 }
 
@@ -297,9 +436,9 @@ static void ds2760_battery_write_status(struct ds2760_device_info *di,
 	if (status == di->raw[DS2760_STATUS_REG])
 		return;
 
-	w1_ds2760_write(di->w1_dev, &status, DS2760_STATUS_WRITE_REG, 1);
-	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
-	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
+	w1_ds2760_write(di->dev, &status, DS2760_STATUS_WRITE_REG, 1);
+	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
+	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
 }
 
 static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
@@ -308,9 +447,9 @@ static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
 	if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
 		return;
 
-	w1_ds2760_write(di->w1_dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
-	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
-	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
+	w1_ds2760_write(di->dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
+	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
+	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
 }
 
 static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
@@ -325,9 +464,9 @@ static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
 	    tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
 		return;
 
-	w1_ds2760_write(di->w1_dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
-	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
-	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK0);
+	w1_ds2760_write(di->dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
+	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
+	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
 
 	/* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
 	 * values won't be read back by ds2760_battery_read_status() */
@@ -383,9 +522,9 @@ static void ds2760_battery_set_charged_work(struct work_struct *work)
 
 	dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
 
-	w1_ds2760_write(di->w1_dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
-	w1_ds2760_store_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
-	w1_ds2760_recall_eeprom(di->w1_dev, DS2760_EEPROM_BLOCK1);
+	w1_ds2760_write(di->dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
+	w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
+	w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
 
 	/* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
 	 * value won't be read back by ds2760_battery_read_status() */
@@ -504,24 +643,55 @@ static enum power_supply_property ds2760_battery_props[] = {
 	POWER_SUPPLY_PROP_CAPACITY,
 };
 
-static int ds2760_battery_probe(struct platform_device *pdev)
+static int ds2760_pm_notifier(struct notifier_block *notifier,
+			      unsigned long pm_event,
+			      void *unused)
+{
+	struct ds2760_device_info *di =
+		container_of(notifier, struct ds2760_device_info, pm_notifier);
+
+	switch (pm_event) {
+	case PM_HIBERNATION_PREPARE:
+	case PM_SUSPEND_PREPARE:
+		di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
+		break;
+
+	case PM_POST_RESTORE:
+	case PM_POST_HIBERNATION:
+	case PM_POST_SUSPEND:
+		di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
+		power_supply_changed(di->bat);
+		mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
+
+		break;
+
+	case PM_RESTORE_PREPARE:
+	default:
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int w1_ds2760_add_slave(struct w1_slave *sl)
 {
 	struct power_supply_config psy_cfg = {};
-	char status;
-	int retval = 0;
 	struct ds2760_device_info *di;
+	struct device *dev = &sl->dev;
+	int retval = 0;
+	char name[32];
+	char status;
 
-	di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
+	di = devm_kzalloc(dev, sizeof(*di), GFP_KERNEL);
 	if (!di) {
 		retval = -ENOMEM;
 		goto di_alloc_failed;
 	}
 
-	platform_set_drvdata(pdev, di);
+	snprintf(name, sizeof(name), "ds2760-battery.%d", dev->id);
 
-	di->dev				= &pdev->dev;
-	di->w1_dev			= pdev->dev.parent;
-	di->bat_desc.name		= dev_name(&pdev->dev);
+	di->dev				= dev;
+	di->bat_desc.name		= name;
 	di->bat_desc.type		= POWER_SUPPLY_TYPE_BATTERY;
 	di->bat_desc.properties		= ds2760_battery_props;
 	di->bat_desc.num_properties	= ARRAY_SIZE(ds2760_battery_props);
@@ -533,10 +703,12 @@ static int ds2760_battery_probe(struct platform_device *pdev)
 	di->bat_desc.external_power_changed =
 				  ds2760_battery_external_power_changed;
 
-	psy_cfg.drv_data		= di;
+	psy_cfg.drv_data = di;
 
 	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
 
+	sl->family_data = di;
+
 	/* enable sleep mode feature */
 	ds2760_battery_read_status(di);
 	status = di->raw[DS2760_STATUS_REG];
@@ -556,7 +728,7 @@ static int ds2760_battery_probe(struct platform_device *pdev)
 	if (current_accum)
 		ds2760_battery_set_current_accum(di, current_accum);
 
-	di->bat = power_supply_register(&pdev->dev, &di->bat_desc, &psy_cfg);
+	di->bat = power_supply_register(dev, &di->bat_desc, &psy_cfg);
 	if (IS_ERR(di->bat)) {
 		dev_err(di->dev, "failed to register battery\n");
 		retval = PTR_ERR(di->bat);
@@ -566,14 +738,16 @@ static int ds2760_battery_probe(struct platform_device *pdev)
 	INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
 	INIT_DELAYED_WORK(&di->set_charged_work,
 			  ds2760_battery_set_charged_work);
-	di->monitor_wqueue = alloc_ordered_workqueue(dev_name(&pdev->dev),
-						     WQ_MEM_RECLAIM);
+	di->monitor_wqueue = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
 	if (!di->monitor_wqueue) {
 		retval = -ESRCH;
 		goto workqueue_failed;
 	}
 	queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
 
+	di->pm_notifier.notifier_call = ds2760_pm_notifier;
+	register_pm_notifier(&di->pm_notifier);
+
 	goto success;
 
 workqueue_failed:
@@ -584,65 +758,32 @@ success:
 	return retval;
 }
 
-static int ds2760_battery_remove(struct platform_device *pdev)
+static void w1_ds2760_remove_slave(struct w1_slave *sl)
 {
-	struct ds2760_device_info *di = platform_get_drvdata(pdev);
+	struct ds2760_device_info *di = sl->family_data;
 
+	unregister_pm_notifier(&di->pm_notifier);
 	cancel_delayed_work_sync(&di->monitor_work);
 	cancel_delayed_work_sync(&di->set_charged_work);
 	destroy_workqueue(di->monitor_wqueue);
 	power_supply_unregister(di->bat);
-
-	return 0;
-}
-
-#ifdef CONFIG_PM
-
-static int ds2760_battery_suspend(struct platform_device *pdev,
-				  pm_message_t state)
-{
-	struct ds2760_device_info *di = platform_get_drvdata(pdev);
-
-	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
-
-	return 0;
-}
-
-static int ds2760_battery_resume(struct platform_device *pdev)
-{
-	struct ds2760_device_info *di = platform_get_drvdata(pdev);
-
-	di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
-	power_supply_changed(di->bat);
-
-	mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
-
-	return 0;
 }
 
-#else
-
-#define ds2760_battery_suspend NULL
-#define ds2760_battery_resume NULL
-
-#endif /* CONFIG_PM */
-
-MODULE_ALIAS("platform:ds2760-battery");
-
-static struct platform_driver ds2760_battery_driver = {
-	.driver = {
-		.name = "ds2760-battery",
-	},
-	.probe	  = ds2760_battery_probe,
-	.remove   = ds2760_battery_remove,
-	.suspend  = ds2760_battery_suspend,
-	.resume	  = ds2760_battery_resume,
+static struct w1_family_ops w1_ds2760_fops = {
+	.add_slave	= w1_ds2760_add_slave,
+	.remove_slave	= w1_ds2760_remove_slave,
+	.groups		= w1_ds2760_groups,
 };
 
-module_platform_driver(ds2760_battery_driver);
+static struct w1_family w1_ds2760_family = {
+	.fid		= W1_FAMILY_DS2760,
+	.fops		= &w1_ds2760_fops,
+};
+module_w1_family(w1_ds2760_family);
 
-MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
 	      "Matt Reimer <mreimer@vpop.net>, "
 	      "Anton Vorontsov <cbou@mail.ru>");
-MODULE_DESCRIPTION("ds2760 battery driver");
+MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));