Update ITHC from module repo

Changes: - Added some comments and fixed a few checkpatch warnings - Improved CPU latency QoS handling - Retry reading the report descriptor on error / timeout Based on quo/ithc-linux@0b8b45d Signed-off-by: Dorian Stoll <dorian.stoll@tmsp.io> Patchset: ithc
linux-surface · Oct 23, 2023 · da50bc9 · da50bc9
1 parent c119659
commit da50bc9
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Showing 7 changed files with 623 additions and 236 deletions.
diff --git a/drivers/hid/ithc/ithc-debug.c b/drivers/hid/ithc/ithc-debug.c
@@ -1,10 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+
 #include "ithc.h"
 
-void ithc_log_regs(struct ithc *ithc) {
-	if (!ithc->prev_regs) return;
-	u32 __iomem *cur = (__iomem void*)ithc->regs;
-	u32 *prev = (void*)ithc->prev_regs;
-	for (int i = 1024; i < sizeof *ithc->regs / 4; i++) {
+void ithc_log_regs(struct ithc *ithc)
+{
+	if (!ithc->prev_regs)
+		return;
+	u32 __iomem *cur = (__iomem void *)ithc->regs;
+	u32 *prev = (void *)ithc->prev_regs;
+	for (int i = 1024; i < sizeof(*ithc->regs) / 4; i++) {
 		u32 x = readl(cur + i);
 		if (x != prev[i]) {
 			pci_info(ithc->pci, "reg %04x: %08x -> %08x\n", i * 4, prev[i], x);
@@ -13,55 +17,79 @@ void ithc_log_regs(struct ithc *ithc) {
 	}
 }
 
-static ssize_t ithc_debugfs_cmd_write(struct file *f, const char __user *buf, size_t len, loff_t *offset) {
+static ssize_t ithc_debugfs_cmd_write(struct file *f, const char __user *buf, size_t len,
+	loff_t *offset)
+{
+	// Debug commands consist of a single letter followed by a list of numbers (decimal or
+	// hexadecimal, space-separated).
 	struct ithc *ithc = file_inode(f)->i_private;
 	char cmd[256];
-	if (!ithc || !ithc->pci) return -ENODEV;
-	if (!len) return -EINVAL;
-	if (len >= sizeof cmd) return -EINVAL;
-	if (copy_from_user(cmd, buf, len)) return -EFAULT;
+	if (!ithc || !ithc->pci)
+		return -ENODEV;
+	if (!len)
+		return -EINVAL;
+	if (len >= sizeof(cmd))
+		return -EINVAL;
+	if (copy_from_user(cmd, buf, len))
+		return -EFAULT;
 	cmd[len] = 0;
-	if (cmd[len-1] == '\n') cmd[len-1] = 0;
+	if (cmd[len-1] == '\n')
+		cmd[len-1] = 0;
 	pci_info(ithc->pci, "debug command: %s\n", cmd);
+
+	// Parse the list of arguments into a u32 array.
 	u32 n = 0;
 	const char *s = cmd + 1;
 	u32 a[32];
 	while (*s && *s != '\n') {
-		if (n >= ARRAY_SIZE(a)) return -EINVAL;
-		if (*s++ != ' ') return -EINVAL;
+		if (n >= ARRAY_SIZE(a))
+			return -EINVAL;
+		if (*s++ != ' ')
+			return -EINVAL;
 		char *e;
 		a[n++] = simple_strtoul(s, &e, 0);
-		if (e == s) return -EINVAL;
+		if (e == s)
+			return -EINVAL;
 		s = e;
 	}
 	ithc_log_regs(ithc);
-	switch(cmd[0]) {
+
+	// Execute the command.
+	switch (cmd[0]) {
 	case 'x': // reset
 		ithc_reset(ithc);
 		break;
 	case 'w': // write register: offset mask value
-		if (n != 3 || (a[0] & 3)) return -EINVAL;
-		pci_info(ithc->pci, "debug write 0x%04x = 0x%08x (mask 0x%08x)\n", a[0], a[2], a[1]);
+		if (n != 3 || (a[0] & 3))
+			return -EINVAL;
+		pci_info(ithc->pci, "debug write 0x%04x = 0x%08x (mask 0x%08x)\n",
+			a[0], a[2], a[1]);
 		bitsl(((__iomem u32 *)ithc->regs) + a[0] / 4, a[1], a[2]);
 		break;
 	case 'r': // read register: offset
-		if (n != 1 || (a[0] & 3)) return -EINVAL;
-		pci_info(ithc->pci, "debug read 0x%04x = 0x%08x\n", a[0], readl(((__iomem u32 *)ithc->regs) + a[0] / 4));
+		if (n != 1 || (a[0] & 3))
+			return -EINVAL;
+		pci_info(ithc->pci, "debug read 0x%04x = 0x%08x\n", a[0],
+			readl(((__iomem u32 *)ithc->regs) + a[0] / 4));
 		break;
 	case 's': // spi command: cmd offset len data...
 		// read config: s 4 0 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 		// set touch cfg: s 6 12 4 XX
-		if (n < 3 || a[2] > (n - 3) * 4) return -EINVAL;
+		if (n < 3 || a[2] > (n - 3) * 4)
+			return -EINVAL;
 		pci_info(ithc->pci, "debug spi command %u with %u bytes of data\n", a[0], a[2]);
 		if (!CHECK(ithc_spi_command, ithc, a[0], a[1], a[2], a + 3))
-			for (u32 i = 0; i < (a[2] + 3) / 4; i++) pci_info(ithc->pci, "resp %u = 0x%08x\n", i, a[3+i]);
+			for (u32 i = 0; i < (a[2] + 3) / 4; i++)
+				pci_info(ithc->pci, "resp %u = 0x%08x\n", i, a[3+i]);
 		break;
 	case 'd': // dma command: cmd len data...
 		// get report descriptor: d 7 8 0 0
 		// enable multitouch: d 3 2 0x0105
-		if (n < 2 || a[1] > (n - 2) * 4) return -EINVAL;
+		if (n < 2 || a[1] > (n - 2) * 4)
+			return -EINVAL;
 		pci_info(ithc->pci, "debug dma command %u with %u bytes of data\n", a[0], a[1]);
-		if (ithc_dma_tx(ithc, a[0], a[1], a + 2)) pci_err(ithc->pci, "dma tx failed\n");
+		if (ithc_dma_tx(ithc, a[0], a[1], a + 2))
+			pci_err(ithc->pci, "dma tx failed\n");
 		break;
 	default:
 		return -EINVAL;
@@ -75,21 +103,27 @@ static const struct file_operations ithc_debugfops_cmd = {
 	.write = ithc_debugfs_cmd_write,
 };
 
-static void ithc_debugfs_devres_release(struct device *dev, void *res) {
+static void ithc_debugfs_devres_release(struct device *dev, void *res)
+{
 	struct dentry **dbgm = res;
-	if (*dbgm) debugfs_remove_recursive(*dbgm);
+	if (*dbgm)
+		debugfs_remove_recursive(*dbgm);
 }
 
-int ithc_debug_init(struct ithc *ithc) {
-	struct dentry **dbgm = devres_alloc(ithc_debugfs_devres_release, sizeof *dbgm, GFP_KERNEL);
-	if (!dbgm) return -ENOMEM;
+int ithc_debug_init(struct ithc *ithc)
+{
+	struct dentry **dbgm = devres_alloc(ithc_debugfs_devres_release, sizeof(*dbgm), GFP_KERNEL);
+	if (!dbgm)
+		return -ENOMEM;
 	devres_add(&ithc->pci->dev, dbgm);
 	struct dentry *dbg = debugfs_create_dir(DEVNAME, NULL);
-	if (IS_ERR(dbg)) return PTR_ERR(dbg);
+	if (IS_ERR(dbg))
+		return PTR_ERR(dbg);
 	*dbgm = dbg;
 
 	struct dentry *cmd = debugfs_create_file("cmd", 0220, dbg, ithc, &ithc_debugfops_cmd);
-	if (IS_ERR(cmd)) return PTR_ERR(cmd);
+	if (IS_ERR(cmd))
+		return PTR_ERR(cmd);
 
 	return 0;
 }