From f1801904eeb79f46e7854e4d18c7107160a16093 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jean-Fran=C3=A7ois=20Moine?= Date: Mon, 27 Feb 2012 07:48:32 -0300 Subject: [PATCH] [media] gspca - zc3xx: Do automatic transfer control for hv7131r and pas202b MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The bridge register 11 reports the current transfer status. This value is used to know about a possible overflow and to adjust the transfer parameters (registers 07 and 08). Signed-off-by: Jean-François Moine Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/zc3xx.c | 134 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) diff --git a/drivers/media/video/gspca/zc3xx.c b/drivers/media/video/gspca/zc3xx.c index c02fb31..d6175f5 100644 --- a/drivers/media/video/gspca/zc3xx.c +++ b/drivers/media/video/gspca/zc3xx.c @@ -57,6 +57,9 @@ struct sd { struct gspca_ctrl ctrls[NCTRLS]; + struct work_struct work; + struct workqueue_struct *work_thread; + u8 reg08; /* webcam compression quality */ u8 bridge; @@ -5932,6 +5935,9 @@ static void setquality(struct gspca_dev *gspca_dev) case SENSOR_OV7620: reg07 = 0x30; break; + case SENSOR_HV7131R: + case SENSOR_PAS202B: + return; /* done by work queue */ } reg_w(gspca_dev, sd->reg08, ZC3XX_R008_CLOCKSETTING); if (reg07 != 0) @@ -6069,6 +6075,114 @@ static void setautogain(struct gspca_dev *gspca_dev) reg_w(gspca_dev, autoval, 0x0180); } +/* update the transfer parameters */ +/* This function is executed from a work queue. */ +/* The exact use of the bridge registers 07 and 08 is not known. + * The following algorithm has been adapted from ms-win traces */ +static void transfer_update(struct work_struct *work) +{ + struct sd *sd = container_of(work, struct sd, work); + struct gspca_dev *gspca_dev = &sd->gspca_dev; + int change, good; + u8 reg07, reg11; + + /* synchronize with the main driver and initialize the registers */ + mutex_lock(&gspca_dev->usb_lock); + reg07 = 0; /* max */ + reg_w(gspca_dev, reg07, 0x0007); + reg_w(gspca_dev, sd->reg08, ZC3XX_R008_CLOCKSETTING); + mutex_unlock(&gspca_dev->usb_lock); + + good = 0; + for (;;) { + msleep(100); + + /* get the transfer status */ + /* the bit 0 of the bridge register 11 indicates overflow */ + mutex_lock(&gspca_dev->usb_lock); + if (!gspca_dev->present || !gspca_dev->streaming) + goto err; + reg11 = reg_r(gspca_dev, 0x0011); + if (gspca_dev->usb_err < 0 + || !gspca_dev->present || !gspca_dev->streaming) + goto err; + + change = reg11 & 0x01; + if (change) { /* overflow */ + switch (reg07) { + case 0: /* max */ + reg07 = sd->sensor == SENSOR_HV7131R + ? 0x30 : 0x32; + if (sd->reg08 != 0) { + change = 3; + sd->reg08--; + } + break; + case 0x32: + reg07 -= 4; + break; + default: + reg07 -= 2; + break; + case 2: + change = 0; /* already min */ + break; + } + good = 0; + } else { /* no overflow */ + if (reg07 != 0) { /* if not max */ + good++; + if (good >= 10) { + good = 0; + change = 1; + reg07 += 2; + switch (reg07) { + case 0x30: + if (sd->sensor == SENSOR_PAS202B) + reg07 += 2; + break; + case 0x32: + case 0x34: + reg07 = 0; + break; + } + } + } else { /* reg07 max */ + if (sd->reg08 < sizeof jpeg_qual - 1) { + good++; + if (good > 10) { + sd->reg08++; + change = 2; + } + } + } + } + if (change) { + if (change & 1) { + reg_w(gspca_dev, reg07, 0x0007); + if (gspca_dev->usb_err < 0 + || !gspca_dev->present + || !gspca_dev->streaming) + goto err; + } + if (change & 2) { + reg_w(gspca_dev, sd->reg08, + ZC3XX_R008_CLOCKSETTING); + if (gspca_dev->usb_err < 0 + || !gspca_dev->present + || !gspca_dev->streaming) + goto err; + jpeg_set_qual(sd->jpeg_hdr, + jpeg_qual[sd->reg08]); + } + } + mutex_unlock(&gspca_dev->usb_lock); + } + return; +err: + mutex_unlock(&gspca_dev->usb_lock); +} + static void send_unknown(struct gspca_dev *gspca_dev, int sensor) { reg_w(gspca_dev, 0x01, 0x0000); /* bridge reset */ @@ -6398,6 +6512,8 @@ static int sd_config(struct gspca_dev *gspca_dev, gspca_dev->cam.ctrls = sd->ctrls; sd->reg08 = REG08_DEF; + INIT_WORK(&sd->work, transfer_update); + return 0; } @@ -6807,6 +6923,18 @@ static int sd_start(struct gspca_dev *gspca_dev) } setautogain(gspca_dev); + + /* start the transfer update thread if needed */ + if (gspca_dev->usb_err >= 0) { + switch (sd->sensor) { + case SENSOR_HV7131R: + case SENSOR_PAS202B: + sd->work_thread = create_singlethread_workqueue(MODULE_NAME); + queue_work(sd->work_thread, &sd->work); + break; + } + } + return gspca_dev->usb_err; } @@ -6815,6 +6943,12 @@ static void sd_stop0(struct gspca_dev *gspca_dev) { struct sd *sd = (struct sd *) gspca_dev; + if (sd->work_thread != NULL) { + mutex_unlock(&gspca_dev->usb_lock); + destroy_workqueue(sd->work_thread); + mutex_lock(&gspca_dev->usb_lock); + sd->work_thread = NULL; + } if (!gspca_dev->present) return; send_unknown(gspca_dev, sd->sensor); -- 2.7.4