Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753031Ab1ECONJ (ORCPT ); Tue, 3 May 2011 10:13:09 -0400 Received: from mail-qw0-f46.google.com ([209.85.216.46]:48480 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752992Ab1ECONE convert rfc822-to-8bit (ORCPT ); Tue, 3 May 2011 10:13:04 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=references:in-reply-to:mime-version:content-type:message-id :content-transfer-encoding:cc:from:subject:date:to:x-mailer; b=M9qUvHCIyN20TY6+EWn5q5Y7PGHiQDIk6NfgFEfzdkByFIspCxw85zICpEsYrMF4UM 9OL1BZ2b8RFFhngq0EH522R3DDsMfnDDg47JORIpjr7lDXNM1OcMr3QCH23X/dgqWTPz FGzz3oQM1kWdDsShzBCH4PbpVralijvI2Wiac= References: <62821D7C-1637-4F7E-A53A-F52AEB2A6C87@gmail.com> <4DBA8AFE.6080807@cam.ac.uk> In-Reply-To: <4DBA8AFE.6080807@cam.ac.uk> Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii Message-Id: Content-Transfer-Encoding: 8BIT Cc: Yves.Lapointe@analog.com, Adrian.Flanagan@analog.com, Susan.Pratt@analog.com From: Jean-Francois Dagenais Subject: Re: ad714x driver help and possible bug Date: Tue, 3 May 2011 10:13:10 -0400 To: Jonathan Cameron , Barry Song <21cnbao@gmail.com>, linux-kernel@vger.kernel.org, device-drivers-devel@blackfin.uclinux.org, Michael Hennerich , linux-input@vger.kernel.org X-Mailer: Apple Mail (2.1084) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10630 Lines: 209 On Apr 29, 2011, at 5:55, Jonathan Cameron wrote: > Cc'd input, and analog devices driver list... > > On 04/28/11 19:17, Jean-Francois Dagenais wrote: >> Hi all, >> >> I am having trouble getting the ad714x (i2c) driver to work in my >> test setup. I am using the VGA i2c bus to talk to the ad7147 I have. >> I used INTA of a PCI ethernet slot in my PC. I enabled the PCI device >> without the driver module loaded. I then give the interrupt number >> to ad714x through the struct i2c_board_info. I actually tried the >> same setup on two PCs, one intel graphics, the other nvidia to >> eliminate the i2c master as a possible cause of my problem. >> >> The device is successfully loaded and I can see the interrupts going. >> The eventN device created under /dev/input never spit out anything >> and so I added printks in the threaded ISR handler to see what is >> going on. >> >> I only have a wheel with 8 stages. In ad714x_wheel_state_machine() I >> see that upon the first interrupt, the state goes from IDLE to >> JITTER. After this the JITTER case checks that c_state == mask (with >> mask being 0xff in our case). This condition is never met and the >> driver stays indefinitely in this state. After lifting my finger from >> the wheel, the chip settles down to scanning every so many >> milliseconds. >> >> The STAGE_COMPLETE_INT_STATUS is always 0 when my finger is off, but >> varies a lot while my finger is on (while interrupt frequency is >> high). Looking at the value of STAGE_COMPLETE_INT_STATUS in binary >> reveals that the set bits are always in groups, e.g. 0x0007 or 0x001C >> or 0x0081(I imagine a roll-over of our start_stage-end_stage (0-7)). >> There seems to be a timing aspect here. I added a spin counter in the >> threaded ISR to delay reading the 3 registers and that seemed to make >> the c_state change a little. >> >> I modified the code that reads the 3 registers right after the >> mutex_lock in ad714x_interrupt_thread so that the >> STAGE_COMPLETE_INT_STATUS is read before the other two (LOW and HIGH >> regs). The result was surprising. The COMPLETE reg did read 0xff now >> and the JITTER case went past the "if(c_state == mask)" but later >> crashed (divide by 0) in ad714x_wheel_cal_abs_pos() called from the >> JITTER case. >> >> >> Here's the initial configuration I give the driver: >> >> static struct ad714x_wheel_plat wheel_platform_data = { >> .start_stage = 0, // int start_stage; >> .end_stage = 7, // int end_stage; >> .max_coord = 128, // int max_coord; >> }; >> >> static struct ad714x_platform_data wheel_dev_platform_data = { >> .slider_num = 0, >> .wheel_num = 1, >> .touchpad_num = 0, >> .button_num = 0, >> .slider = 0, >> .wheel = &wheel_platform_data, // struct ad714x_wheel_plat *wheel; >> .touchpad = 0, // struct ad714x_touchpad_plat *touchpad; >> .button = 0, // struct ad714x_button_plat *button; >> .stage_cfg_reg = { /* unsigned short stage_cfg_reg[STAGE_NUM][STAGE_CFGREG_NUM] */ >> {0xfffe, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xfffb, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xffef, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xffbf, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xfeff, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xfbff, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xefff, 0x3fff, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> {0xffff, 0x3ffe, 0, 0x2626, 0x3e8, 0x3e8, 0x1388, 0x1388 }, >> >> {0xffff, 0x3fff, 0, 0x0606, 0x01f4, 0x01f4, 0x0320, 0x0320}, >> {0xffff, 0x3fff, 0, 0x0606, 0x01f4, 0x01f4, 0x0320, 0x0320}, >> {0xffff, 0x3fff, 0, 0x0606, 0x01f4, 0x01f4, 0x0320, 0x0320}, >> {0xffff, 0x3fff, 0, 0x0606, 0x01f4, 0x01f4, 0x0320, 0x0320}, >> }, >> .sys_cfg_reg = {0x027e, 0x00ff, 0x3233, 0x0819, 0x0832, 0x0000, 0x00ff, 0}, /* unsigned short sys_cfg_reg[SYS_CFGREG_NUM] */ >> //.sys_cfg_reg = {0x2b2, 0xfff, 0x3233, 0x819, 0x832, 0xcff, 0xcff, 0x0}, /* unsigned short sys_cfg_reg[SYS_CFGREG_NUM] */ >> }; >> > >> >> I also had to change the request_threaded_irq flags to specify >> IRQF_ONESHOT so the kernel keeps the interrupt masked while we are >> running ad714x_interrupt_thread(). Otherwise we were getting storms >> of interrupts each time only one was requested. I am wondering if >> this should be pulled back to the mainline kernel? >> >> Thanks for pointers and clues! >> > here's the printk I added to ad714x_wheel_state_machine() mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1); h_state = ad714x->h_state & mask; c_state = ad714x->c_state & mask; dev_dbg(ad714x->dev, "interrupt state:%d mask:0x%x l:0x%x h:0x%x c:0x%x\n", sw->state, (u32)mask, (u32)ad714x->l_state, (u32)ad714x->h_state, (u32)ad714x->c_state); Here what it looks like upon loading a module which does the i2c_new_device of the AD7147: <7>[58302.186886] my-pci-stub 0000:01:04.0: claimed by my platform module PCI stub <6>[58302.186903] my-pci-stub 0000:01:04.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17 <6>[58302.189815] ad714x_captouch 9-002c: found AD7147(A) captouch, rev:1 <6>[58302.427237] input: Unspecified device as /devices/virtual/input/input8 [ pause here while my hand goes from my mouse and keyboard to the wheel on the AD7147 ] <7>[58311.646183] ad714x_captouch 9-002c: interrupt state:0 mask:0xff l:0x0 h:0x18 c:0x1c <7>[58311.646192] ad714x_captouch 9-002c: case IDLE in if <7>[58311.655436] ad714x_captouch 9-002c: wheel 0 touched <7>[58311.663087] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x18 c:0x7 <7>[58311.674562] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x18 c:0x81 <7>[58311.686803] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x18 c:0x81 <7>[58311.699147] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x18 c:0x81 <7>[58311.711430] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x18 c:0x81 <7>[58311.723585] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x18 c:0x81 <7>[58311.736017] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x81 <7>[58311.748298] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x81 <7>[58311.760581] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x81 <7>[58311.772800] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x81 <7>[58311.785176] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x81 <7>[58311.797473] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x81 <7>[58311.809651] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x10 c:0x81 [ here I lift my finger ] <7>[58311.822059] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.834345] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.846582] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.858800] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.871212] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.883517] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.895802] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.908099] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.920381] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58311.932585] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 [...] <7>[58313.432218] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 <7>[58314.157343] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x81 [... after 2 seconds or so, the rhythm slows down to 2 interrupts per second or so ] <7>[58314.169629] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x80 <7>[58314.976518] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x80 <7>[58315.783342] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x0 c:0x80 There is a clue in what I did next. I added a wait time in the isr thread function like so: static irqreturn_t ad714x_interrupt_thread(int irq, void *data) { struct ad714x_chip *ad714x = data; volatile int i; mutex_lock(&ad714x->mutex); i=0xffffff; while(i) --i; ad714x->read(ad714x->dev, STG_LOW_INT_STA_REG, &ad714x->l_state); ad714x->read(ad714x->dev, STG_HIGH_INT_STA_REG, &ad714x->h_state); ad714x->read(ad714x->dev, STG_COM_INT_STA_REG, &ad714x->c_state); [ ... ] this changes the above trace to these values: while touching the wheel: <7>[63085.414268] ad714x_captouch 9-002c: interrupt state:0 mask:0xff l:0x0 h:0x70 c:0x60 <7>[63085.414277] ad714x_captouch 9-002c: case IDLE in if <7>[63085.423519] ad714x_captouch 9-002c: wheel 0 touched <7>[63085.578931] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x70 c:0x18 <7>[63085.736079] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x70 c:0x3 <7>[63085.832304] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x70 c:0x60 <7>[63086.938334] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x30 c:0x60 <7>[63087.030835] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x60 <7>[63087.122909] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x60 <7>[63087.215014] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x60 <7>[63087.307071] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x60 <7>[63087.399367] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x60 <7>[63087.739386] ad714x_captouch 9-002c: interrupt state:1 mask:0xff l:0x0 h:0x38 c:0x83 Again, notice the state going from 0 (IDLE) to 1(JITTER), and never entering the "if" in the JITTER case (needs mask == c_state). The HIGH register varies a lot while I move my finger around, but the COMPLETE looks like its always going and being cleared. I mentioned before that reading the COMPLETE status reg before the LOW and HIGH produces completely different results. I am suspecting the register configuration we use is off somehow, I will review them thoroughly. Aside from this we are running out of leads here, anyone has input on this? Thanks in advance! JFD -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/