[PATCH] ims-pcu: Add commands supported by the new version of the FW

[Andrey Smirnov <andrew.smirnov@gmail.com>]

New version of the PCU firmware supports two new commands:
  - IMS_PCU_CMD_OFN_SET_CONFIG which allows to write data to the
  registers of one finger navigation(OFN) chip present on the device
  - IMS_PCU_CMD_OFN_GET_CONFIG which allows to read data form the
  registers of said chip.

This commit adds two helper functions to use those commands and sysfs
attributes to use them. It also exposes some OFN configuration
parameters via sysfs.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/input/misc/ims-pcu.c | 274 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 263 insertions(+), 11 deletions(-)

diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
index e204f26..050c960 100644
--- a/drivers/input/misc/ims-pcu.c
+++ b/drivers/input/misc/ims-pcu.c
@@ -68,6 +68,9 @@ struct ims_pcu {
 	char bl_version[IMS_PCU_BL_VERSION_LEN];
 	char reset_reason[IMS_PCU_BL_RESET_REASON_LEN];
 	int update_firmware_status;
+	u8 device_id;
+
+	u8 ofn_reg_addr;
 
 	struct usb_interface *ctrl_intf;
 
@@ -371,6 +374,8 @@ static void ims_pcu_destroy_gamepad(struct ims_pcu *pcu)
 #define IMS_PCU_CMD_GET_DEVICE_ID	0xae
 #define IMS_PCU_CMD_SPECIAL_INFO	0xb0
 #define IMS_PCU_CMD_BOOTLOADER		0xb1	/* Pass data to bootloader */
+#define IMS_PCU_CMD_OFN_SET_CONFIG	0xb3
+#define IMS_PCU_CMD_OFN_GET_CONFIG	0xb4
 
 /* PCU responses */
 #define IMS_PCU_RSP_STATUS		0xc0
@@ -389,6 +394,9 @@ static void ims_pcu_destroy_gamepad(struct ims_pcu *pcu)
 #define IMS_PCU_RSP_GET_DEVICE_ID	0xce
 #define IMS_PCU_RSP_SPECIAL_INFO	0xd0
 #define IMS_PCU_RSP_BOOTLOADER		0xd1	/* Bootloader response */
+#define IMS_PCU_RSP_OFN_SET_CONFIG	0xd2
+#define IMS_PCU_RSP_OFN_GET_CONFIG	0xd3
+
 
 #define IMS_PCU_RSP_EVNT_BUTTONS	0xe0	/* Unsolicited, button state */
 #define IMS_PCU_GAMEPAD_MASK		0x0001ff80UL	/* Bits 7 through 16 */
@@ -1216,6 +1224,226 @@ ims_pcu_update_firmware_status_show(struct device *dev,
 static DEVICE_ATTR(update_firmware_status, S_IRUGO,
 		   ims_pcu_update_firmware_status_show, NULL);
 
+enum pcu_ofn_offsets {
+	OFN_REG_RESULT_LSB_OFFSET = 2,
+	OFN_REG_RESULT_MSB_OFFSET = 3,
+};
+
+static ssize_t ims_pcu_ofn_reg_data_show(struct device *dev,
+					 struct device_attribute *dattr,
+					 char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int error;
+
+	mutex_lock(&pcu->cmd_mutex);
+
+	error = ims_pcu_execute_command(pcu, OFN_GET_CONFIG,
+					&pcu->ofn_reg_addr,
+					sizeof(pcu->ofn_reg_addr));
+	if (error >= 0) {
+		const s16 result = pcu->cmd_buf[OFN_REG_RESULT_MSB_OFFSET] << 8 |
+			           pcu->cmd_buf[OFN_REG_RESULT_LSB_OFFSET];
+		if (result < 0)
+			error = result;
+		else
+			error = scnprintf(buf, PAGE_SIZE, "%x\n", (u8)result);
+	}
+
+	mutex_unlock(&pcu->cmd_mutex);
+
+	return error;
+}
+
+static ssize_t ims_pcu_ofn_reg_data_store(struct device *dev,
+					  struct device_attribute *dattr,
+					  const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int error;
+	int value;
+	u8 buffer[2];
+
+	error = kstrtoint(buf, 0, &value);
+	if (error)
+		return error;
+
+	buffer[0] = pcu->ofn_reg_addr;
+	buffer[1] = (u8) value;
+
+	mutex_lock(&pcu->cmd_mutex);
+
+	error = ims_pcu_execute_command(pcu, OFN_SET_CONFIG,
+					&buffer, sizeof(buffer));
+
+	mutex_unlock(&pcu->cmd_mutex);
+
+	if (!error) {
+		const s16 result = pcu->cmd_buf[OFN_REG_RESULT_MSB_OFFSET] << 8 |
+			           pcu->cmd_buf[OFN_REG_RESULT_LSB_OFFSET];
+		error = result;
+	}
+
+	return error ?: count;
+}
+
+static DEVICE_ATTR(ofn_reg_data, S_IRUGO | S_IWUSR,
+		   ims_pcu_ofn_reg_data_show, ims_pcu_ofn_reg_data_store);
+
+static ssize_t ims_pcu_ofn_reg_addr_show(struct device *dev,
+					 struct device_attribute *dattr,
+					 char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int error;
+
+	mutex_lock(&pcu->cmd_mutex);
+	error = scnprintf(buf, PAGE_SIZE, "%x\n", pcu->ofn_reg_addr);
+	mutex_unlock(&pcu->cmd_mutex);
+
+	return error;
+}
+
+static ssize_t ims_pcu_ofn_reg_addr_store(struct device *dev,
+					  struct device_attribute *dattr,
+					  const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int error;
+	int value;
+
+	error = kstrtoint(buf, 0, &value);
+	if (error)
+		return error;
+
+	mutex_lock(&pcu->cmd_mutex);
+	pcu->ofn_reg_addr = (u8) value;
+	mutex_unlock(&pcu->cmd_mutex);
+
+	return error ?: count;
+}
+
+static DEVICE_ATTR(ofn_reg_addr, S_IRUGO | S_IWUSR,
+		   ims_pcu_ofn_reg_addr_show, ims_pcu_ofn_reg_addr_store);
+
+static ssize_t ims_pcu_ofn_bit_show(u8 addr, u8 nr,
+				    struct device *dev,
+				    struct device_attribute *dattr,
+				    char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int error;
+
+	mutex_lock(&pcu->cmd_mutex);
+
+	error = ims_pcu_execute_command(pcu, OFN_GET_CONFIG,
+					&addr, sizeof(addr));
+	if (error >= 0) {
+		const s16 result = pcu->cmd_buf[OFN_REG_RESULT_MSB_OFFSET] << 8 |
+			           pcu->cmd_buf[OFN_REG_RESULT_LSB_OFFSET];
+		if (result < 0)
+			error = result;
+		else
+			error = scnprintf(buf, PAGE_SIZE, "%d\n",
+					  !!(result & (1 << nr)));
+	}
+
+	mutex_unlock(&pcu->cmd_mutex);
+	return error;
+}
+
+static ssize_t ims_pcu_ofn_bit_store(u8 addr, u8 nr,
+				     struct device *dev,
+				     struct device_attribute *dattr,
+				     const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int error;
+	int value;
+	u8 contents;
+
+
+	error = kstrtoint(buf, 0, &value);
+	if (error)
+		return error;
+
+	if (value > 1)
+		return -EINVAL;
+
+	mutex_lock(&pcu->cmd_mutex);
+
+	error = ims_pcu_execute_command(pcu, OFN_GET_CONFIG,
+					&addr, sizeof(addr));
+	if (error < 0)
+		goto exit;
+
+	{
+		const s16 result = pcu->cmd_buf[OFN_REG_RESULT_MSB_OFFSET] << 8 |
+			           pcu->cmd_buf[OFN_REG_RESULT_LSB_OFFSET];
+		if (result < 0) {
+			error = result;
+			goto exit;
+		}
+		contents = (u8) result;
+	}
+
+	if (value)
+		contents |= 1 << nr;
+	else
+		contents &= ~(1 << nr);
+
+	{
+		const u8 buffer[] = { addr, contents };
+		error = ims_pcu_execute_command(pcu, OFN_SET_CONFIG,
+						&buffer, sizeof(buffer));
+	}
+
+exit:
+	mutex_unlock(&pcu->cmd_mutex);
+
+	if (!error) {
+		const s16 result = pcu->cmd_buf[OFN_REG_RESULT_MSB_OFFSET] << 8 |
+			           pcu->cmd_buf[OFN_REG_RESULT_LSB_OFFSET];
+		error = result;
+	}
+
+	return error ?: count;
+}
+
+
+#define IMS_PCU_BIT_ATTR(name, addr, nr)				\
+	static ssize_t ims_pcu_##name##_show(struct device *dev,	\
+					     struct device_attribute *dattr, \
+					     char *buf)			\
+	{								\
+		return ims_pcu_ofn_bit_show(addr, nr, dev, dattr, buf);	\
+	}								\
+									\
+	static ssize_t ims_pcu_##name##_store(struct device *dev,	\
+					      struct device_attribute *dattr, \
+					      const char *buf, size_t count) \
+	{								\
+		return ims_pcu_ofn_bit_store(addr, nr, dev, dattr, buf, count); \
+	}								\
+									\
+	static DEVICE_ATTR(name, S_IRUGO | S_IWUSR,			\
+			   ims_pcu_##name##_show, ims_pcu_##name##_store)
+
+IMS_PCU_BIT_ATTR(ofn_engine_enable,   0x60, 7);
+IMS_PCU_BIT_ATTR(ofn_speed_enable,    0x60, 6);
+IMS_PCU_BIT_ATTR(ofn_assert_enable,   0x60, 5);
+IMS_PCU_BIT_ATTR(ofn_xyquant_enable,  0x60, 4);
+IMS_PCU_BIT_ATTR(ofn_xyscale_enable,  0x60, 1);
+
+IMS_PCU_BIT_ATTR(ofn_scale_x2,        0x63, 6);
+IMS_PCU_BIT_ATTR(ofn_scale_y2,        0x63, 7);
+
 static struct attribute *ims_pcu_attrs[] = {
 	&ims_pcu_attr_part_number.dattr.attr,
 	&ims_pcu_attr_serial_number.dattr.attr,
@@ -1226,6 +1454,18 @@ static struct attribute *ims_pcu_attrs[] = {
 	&dev_attr_reset_device.attr,
 	&dev_attr_update_firmware.attr,
 	&dev_attr_update_firmware_status.attr,
+
+#define IMS_PCU_ATTRS_OFN_START_OFFSET (9)
+
+	&dev_attr_ofn_reg_data.attr,
+	&dev_attr_ofn_reg_addr.attr,
+	&dev_attr_ofn_engine_enable.attr,
+	&dev_attr_ofn_speed_enable.attr,
+	&dev_attr_ofn_assert_enable.attr,
+	&dev_attr_ofn_xyquant_enable.attr,
+	&dev_attr_ofn_xyscale_enable.attr,
+	&dev_attr_ofn_scale_x2.attr,
+	&dev_attr_ofn_scale_y2.attr,
 	NULL
 };
 
@@ -1244,8 +1484,21 @@ static umode_t ims_pcu_is_attr_visible(struct kobject *kobj,
 			mode = 0;
 		}
 	} else {
-		if (attr == &dev_attr_update_firmware_status.attr)
+		if (attr == &dev_attr_update_firmware_status.attr) {
 			mode = 0;
+		} else if (pcu->device_id == 5) {
+			/*
+			   PCU-B devices, both GEN_1 and GEN_2(device_id == 5),
+			   have no OFN sensor so exposing those attributes
+			   for them does not make any sense
+			*/
+			int i;
+			for (i = IMS_PCU_ATTRS_OFN_START_OFFSET; ims_pcu_attrs[i]; i++)
+				if (attr == ims_pcu_attrs[i]) {
+					mode = 0;
+					break;
+				}
+		}
 	}
 
 	return mode;
@@ -1624,7 +1877,6 @@ static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
 	static atomic_t device_no = ATOMIC_INIT(0);
 
 	const struct ims_pcu_device_info *info;
-	u8 device_id;
 	int error;
 
 	error = ims_pcu_get_device_info(pcu);
@@ -1633,7 +1885,7 @@ static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
 		return error;
 	}
 
-	error = ims_pcu_identify_type(pcu, &device_id);
+	error = ims_pcu_identify_type(pcu, &pcu->device_id);
 	if (error) {
 		dev_err(pcu->dev,
 			"Failed to identify device, error: %d\n", error);
@@ -1645,9 +1897,9 @@ static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
 		return 0;
 	}
 
-	if (device_id >= ARRAY_SIZE(ims_pcu_device_info) ||
-	    !ims_pcu_device_info[device_id].keymap) {
-		dev_err(pcu->dev, "Device ID %d is not valid\n", device_id);
+	if (pcu->device_id >= ARRAY_SIZE(ims_pcu_device_info) ||
+	    !ims_pcu_device_info[pcu->device_id].keymap) {
+		dev_err(pcu->dev, "Device ID %d is not valid\n", pcu->device_id);
 		/* Same as above, punt to userspace */
 		return 0;
 	}
@@ -1659,7 +1911,7 @@ static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
 	if (error)
 		return error;
 
-	info = &ims_pcu_device_info[device_id];
+	info = &ims_pcu_device_info[pcu->device_id];
 	error = ims_pcu_setup_buttons(pcu, info->keymap, info->keymap_len);
 	if (error)
 		goto err_destroy_backlight;
@@ -1783,14 +2035,14 @@ static int ims_pcu_probe(struct usb_interface *intf,
 	if (error)
 		goto err_stop_io;
 
-	error = sysfs_create_group(&intf->dev.kobj, &ims_pcu_attr_group);
-	if (error)
-		goto err_stop_io;
-
 	error = pcu->bootloader_mode ?
 			ims_pcu_init_bootloader_mode(pcu) :
 			ims_pcu_init_application_mode(pcu);
 	if (error)
+		goto err_stop_io;
+
+	error = sysfs_create_group(&intf->dev.kobj, &ims_pcu_attr_group);
+	if (error)
 		goto err_remove_sysfs;
 
 	return 0;
-- 
1.8.3.2