[PATCH] mfd: altr-a10sr: Add Arria10 SR sysfs attributes

[thor.thayer@linux.intel.com]

From: Thor Thayer <thor.thayer@linux.intel.com>

Add the Altera Arria10 DevKit sysfs attributes to the
MFD device. Update copyright and email.

Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
---
 drivers/mfd/altera-a10sr.c | 98 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 95 insertions(+), 3 deletions(-)

diff --git a/drivers/mfd/altera-a10sr.c b/drivers/mfd/altera-a10sr.c
index 06e1f7f..8c51818 100644
--- a/drivers/mfd/altera-a10sr.c
+++ b/drivers/mfd/altera-a10sr.c
@@ -1,9 +1,9 @@
 /*
  * Altera Arria10 DevKit System Resource MFD Driver
  *
- * Author: Thor Thayer <tthayer@opensource.altera.com>
+ * Author: Thor Thayer <thor.thayer@linux.intel.com>
  *
- * Copyright Intel Corporation (C) 2014-2016. All Rights Reserved
+ * Copyright Intel Corporation (C) 2014-2017. All Rights Reserved
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -35,6 +35,89 @@
 	},
 };
 
+/* Add sysfs interface for MAX5 System Resource Controller */
+static unsigned int a10sr_reg_addr;
+static ssize_t a10sr_reg_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "0x%02x\n", a10sr_reg_addr);
+}
+
+static ssize_t a10sr_reg_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret = kstrtouint(buf, 0, &a10sr_reg_addr);
+
+	if (ret || (a10sr_reg_addr < 0) ||
+	    (a10sr_reg_addr > ALTR_A10SR_PMBUS_REG)) {
+		a10sr_reg_addr = 0;
+		dev_err(dev, "Invalid register address\n");
+		return -EINVAL;
+	}
+	return (ssize_t)count;
+}
+
+static ssize_t a10sr_val_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	int ret;
+	unsigned int val;
+	struct altr_a10sr *a10sr_regs = dev_get_drvdata(dev);
+
+	ret = regmap_read(a10sr_regs->regmap, a10sr_reg_addr, &val);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read 0x%x\n", a10sr_reg_addr);
+		return -EIO;
+	}
+
+	return sprintf(buf, "0x%02x\n", val);
+}
+
+static ssize_t a10sr_val_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int ret;
+	unsigned int val;
+	struct altr_a10sr *a10sr_regs = dev_get_drvdata(dev);
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(a10sr_regs->regmap, a10sr_reg_addr, val);
+	if (ret) {
+		dev_err(dev, "Failed to write value 0x%02x to address 0x%x",
+			val, a10sr_reg_addr);
+		return -EIO;
+	}
+	return count;
+}
+
+static ssize_t a10sr_version(struct device *dev,
+			     struct device_attribute *devattr, char *buf)
+{
+	a10sr_reg_addr = ALTR_A10SR_VERSION_READ;
+	return a10sr_val_show(dev, devattr, buf);
+}
+
+/* Define FS entries */
+static DEVICE_ATTR(max5_version, 0444, a10sr_version, NULL);
+static DEVICE_ATTR(max5_address, 0644, a10sr_reg_show, a10sr_reg_store);
+static DEVICE_ATTR(max5_value, 0644, a10sr_val_show, a10sr_val_store);
+
+static struct attribute *altr_a10sr_attr[] = {
+	&dev_attr_max5_version.attr,
+	&dev_attr_max5_address.attr,
+	&dev_attr_max5_value.attr,
+	NULL
+};
+
+static const struct attribute_group a10sr_attr_group = {
+	.attrs = altr_a10sr_attr,
+};
+
 static bool altr_a10sr_reg_readable(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
@@ -141,13 +224,22 @@ static int altr_a10sr_spi_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	/* Add the A10SR Registers to the device's sysfs */
+	ret = sysfs_create_group(&a10sr->dev->kobj, &a10sr_attr_group);
+	if (ret) {
+		dev_err(&spi->dev, "unable to create sysfs attributes\n");
+		return ret;
+	}
+
 	ret = devm_mfd_add_devices(a10sr->dev, PLATFORM_DEVID_AUTO,
 				   altr_a10sr_subdev_info,
 				   ARRAY_SIZE(altr_a10sr_subdev_info),
 				   NULL, 0, NULL);
-	if (ret)
+	if (ret) {
 		dev_err(a10sr->dev, "Failed to register sub-devices: %d\n",
 			ret);
+		sysfs_remove_group(&a10sr->dev->kobj, &a10sr_attr_group);
+	}
 
 	return ret;
 }
-- 
1.9.1