From: Daniel Ritz Date: Sun, 27 Nov 2005 21:23:38 +0000 (+0100) Subject: [PATCH] USB: input/touchkitusb: handle multiple packets X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5d3202949c9ac6e135d98bde15a8f05ad3fa5849;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git [PATCH] USB: input/touchkitusb: handle multiple packets Some versions of the controller seem to put multiple report packet into a single urb. also it can happen that a packet is split across multiple urbs. unpatched you get a jumpy cursor on some screens. the patch does: - handle multiple packets per urb - handle packets split across multiple urb - check packet type - cleanups Signed-off-by: Daniel Ritz Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/input/touchkitusb.c b/drivers/usb/input/touchkitusb.c index 75e7c12e7189..3b3c7b4120a2 100644 --- a/drivers/usb/input/touchkitusb.c +++ b/drivers/usb/input/touchkitusb.c @@ -1,7 +1,7 @@ /****************************************************************************** * touchkitusb.c -- Driver for eGalax TouchKit USB Touchscreens * - * Copyright (C) 2004 by Daniel Ritz + * Copyright (C) 2004-2005 by Daniel Ritz * Copyright (C) by Todd E. Johnson (mtouchusb.c) * * This program is free software; you can redistribute it and/or @@ -41,15 +41,13 @@ #define TOUCHKIT_MAX_YC 0x07ff #define TOUCHKIT_YC_FUZZ 0x0 #define TOUCHKIT_YC_FLAT 0x0 -#define TOUCHKIT_REPORT_DATA_SIZE 8 +#define TOUCHKIT_REPORT_DATA_SIZE 16 #define TOUCHKIT_DOWN 0x01 -#define TOUCHKIT_POINT_TOUCH 0x81 -#define TOUCHKIT_POINT_NOTOUCH 0x80 -#define TOUCHKIT_GET_TOUCHED(dat) ((((dat)[0]) & TOUCHKIT_DOWN) ? 1 : 0) -#define TOUCHKIT_GET_X(dat) (((dat)[3] << 7) | (dat)[4]) -#define TOUCHKIT_GET_Y(dat) (((dat)[1] << 7) | (dat)[2]) +#define TOUCHKIT_PKT_TYPE_MASK 0xFE +#define TOUCHKIT_PKT_TYPE_REPT 0x80 +#define TOUCHKIT_PKT_TYPE_DIAG 0x0A #define DRIVER_VERSION "v0.1" #define DRIVER_AUTHOR "Daniel Ritz " @@ -62,6 +60,8 @@ MODULE_PARM_DESC(swap_xy, "If set X and Y axes are swapped."); struct touchkit_usb { unsigned char *data; dma_addr_t data_dma; + char buffer[TOUCHKIT_REPORT_DATA_SIZE]; + int buf_len; struct urb *irq; struct usb_device *udev; struct input_dev *input; @@ -77,11 +77,128 @@ static struct usb_device_id touchkit_devices[] = { {} }; +/* helpers to read the data */ +static inline int touchkit_get_touched(char *data) +{ + return (data[0] & TOUCHKIT_DOWN) ? 1 : 0; +} + +static inline int touchkit_get_x(char *data) +{ + return ((data[3] & 0x0F) << 7) | (data[4] & 0x7F); +} + +static inline int touchkit_get_y(char *data) +{ + return ((data[1] & 0x0F) << 7) | (data[2] & 0x7F); +} + + +/* processes one input packet. */ +static void touchkit_process_pkt(struct touchkit_usb *touchkit, + struct pt_regs *regs, char *pkt) +{ + int x, y; + + /* only process report packets */ + if ((pkt[0] & TOUCHKIT_PKT_TYPE_MASK) != TOUCHKIT_PKT_TYPE_REPT) + return; + + if (swap_xy) { + y = touchkit_get_x(pkt); + x = touchkit_get_y(pkt); + } else { + x = touchkit_get_x(pkt); + y = touchkit_get_y(pkt); + } + + input_regs(touchkit->input, regs); + input_report_key(touchkit->input, BTN_TOUCH, touchkit_get_touched(pkt)); + input_report_abs(touchkit->input, ABS_X, x); + input_report_abs(touchkit->input, ABS_Y, y); + input_sync(touchkit->input); +} + + +static int touchkit_get_pkt_len(char *buf) +{ + switch (buf[0] & TOUCHKIT_PKT_TYPE_MASK) { + case TOUCHKIT_PKT_TYPE_REPT: + return 5; + + case TOUCHKIT_PKT_TYPE_DIAG: + return buf[1] + 2; + } + + return 0; +} + +static void touchkit_process(struct touchkit_usb *touchkit, int len, + struct pt_regs *regs) +{ + char *buffer; + int pkt_len, buf_len, pos; + + /* if the buffer contains data, append */ + if (unlikely(touchkit->buf_len)) { + int tmp; + + /* if only 1 byte in buffer, add another one to get length */ + if (touchkit->buf_len == 1) + touchkit->buffer[1] = touchkit->data[0]; + + pkt_len = touchkit_get_pkt_len(touchkit->buffer); + + /* unknown packet: drop everything */ + if (!pkt_len) + return; + + /* append, process */ + tmp = pkt_len - touchkit->buf_len; + memcpy(touchkit->buffer + touchkit->buf_len, touchkit->data, tmp); + touchkit_process_pkt(touchkit, regs, touchkit->buffer); + + buffer = touchkit->data + tmp; + buf_len = len - tmp; + } else { + buffer = touchkit->data; + buf_len = len; + } + + /* only one byte left in buffer */ + if (unlikely(buf_len == 1)) { + touchkit->buffer[0] = buffer[0]; + touchkit->buf_len = 1; + return; + } + + /* loop over the buffer */ + pos = 0; + while (pos < buf_len) { + /* get packet len */ + pkt_len = touchkit_get_pkt_len(buffer + pos); + + /* unknown packet: drop everything */ + if (unlikely(!pkt_len)) + return; + + /* full packet: process */ + if (likely(pkt_len <= buf_len)) { + touchkit_process_pkt(touchkit, regs, buffer + pos); + } else { + /* incomplete packet: save in buffer */ + memcpy(touchkit->buffer, buffer + pos, buf_len - pos); + touchkit->buf_len = buf_len - pos; + } + pos += pkt_len; + } +} + + static void touchkit_irq(struct urb *urb, struct pt_regs *regs) { struct touchkit_usb *touchkit = urb->context; int retval; - int x, y; switch (urb->status) { case 0: @@ -105,20 +222,7 @@ static void touchkit_irq(struct urb *urb, struct pt_regs *regs) goto exit; } - if (swap_xy) { - y = TOUCHKIT_GET_X(touchkit->data); - x = TOUCHKIT_GET_Y(touchkit->data); - } else { - x = TOUCHKIT_GET_X(touchkit->data); - y = TOUCHKIT_GET_Y(touchkit->data); - } - - input_regs(touchkit->input, regs); - input_report_key(touchkit->input, BTN_TOUCH, - TOUCHKIT_GET_TOUCHED(touchkit->data)); - input_report_abs(touchkit->input, ABS_X, x); - input_report_abs(touchkit->input, ABS_Y, y); - input_sync(touchkit->input); + touchkit_process(touchkit, urb->actual_length, regs); exit: retval = usb_submit_urb(urb, GFP_ATOMIC);