From c26ce20c5cb0c5e88da8b756b80317b25e202883 Mon Sep 17 00:00:00 2001
From: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Date: Thu, 24 Sep 2015 13:35:04 -0400
Subject: [PATCH] hidpp10: fix reading memory

Command 0xA2 (Read Sector) takes only a one byte argument for the offset
(entry in the documentation).

Clean up the code and return an error if the page (sector in the doc)
is invalid (to avoid querying the device which would output an
ERR_INVALID_VALUE).

Fixes #15

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
---
 src/hidpp10.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/hidpp10.c b/src/hidpp10.c
index 54508219..4b30d307 100644
--- a/src/hidpp10.c
+++ b/src/hidpp10.c
@@ -208,7 +208,7 @@ out_err:
 /* -------------------------------------------------------------------------- */
 
 static int
-hidpp10_read_memory(struct hidpp10_device *dev, uint8_t page, uint16_t offset,
+hidpp10_read_memory(struct hidpp10_device *dev, uint8_t page, uint8_t offset,
 		    uint8_t bytes[16]);
 
 /* -------------------------------------------------------------------------- */
@@ -438,13 +438,16 @@ hidpp10_get_profile(struct hidpp10_device *dev, int8_t number, struct hidpp10_pr
 	int res;
 	struct hidpp10_profile profile;
 
-	/* FIXME: profile offset appears to be 3, 1 and 2 are garbage */
+	/* Page 0-1 are RAM
+	 * Page 2-31 are Flash
+	 * -> profiles are stored in the Flash */
 	number += 2;
 
 	log_raw(dev->ratbag_device->ratbag, "Fetching profile %d\n", number);
 
 	for (i = 0; i < sizeof(data); i += 16) {
-		res = hidpp10_read_memory(dev, number, i,  &data.data[i]);
+		/* each sector contains 16 bytes of data */
+		res = hidpp10_read_memory(dev, number, i / 2,  &data.data[i]);
 		if (res)
 			return res;
 	}
@@ -814,18 +817,21 @@ hidpp10_get_usb_refresh_rate(struct hidpp10_device *dev,
 		.device_idx = idx, \
 		.sub_id = GET_LONG_REGISTER_REQ, \
 		.address = __CMD_READ_MEMORY, \
-		.parameters = {page, offset & 0xff, offset >> 8 }, \
+		.parameters = {page, offset, 0x00 }, \
 	} \
 }
 
 static int
-hidpp10_read_memory(struct hidpp10_device *dev, uint8_t page, uint16_t offset,
+hidpp10_read_memory(struct hidpp10_device *dev, uint8_t page, uint8_t offset,
 		    uint8_t bytes[16])
 {
 	unsigned idx = dev->index;
-	union hidpp10_message readmem = CMD_READ_MEMORY(idx, page, offset/2);
+	union hidpp10_message readmem = CMD_READ_MEMORY(idx, page, offset);
 	int res;
 
+	if (page > 31)
+		return -EINVAL;
+
 	log_raw(dev->ratbag_device->ratbag,
 		"Reading memory page %d, offset %#x\n",
 		page, offset);