From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH V2] FIX OMAP3:McBSP poll read and write for OMAP3 Date: Thu, 12 Nov 2009 13:11:11 -0800 Message-ID: <20091112211111.GE24837@atomide.com> References: <1256020860-1108-1-git-send-email-charu@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-ewr.mailhop.org ([204.13.248.71]:52886 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754400AbZKLVLJ (ORCPT ); Thu, 12 Nov 2009 16:11:09 -0500 Content-Disposition: inline In-Reply-To: <1256020860-1108-1-git-send-email-charu@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: charu@ti.com Cc: linux-omap@vger.kernel.org, Syed Rafiuddin * charu@ti.com [091019 23:41]: > omap_mcbsp_pollwrite and omap_mcbsp_pollread functions access > McBSP registers as 16-bit registers. > > In OMAP3, McBSP registers (DRR_REG and DXR_REG) are limited to > 32-bit data accesses (L4 Interconnect). 16-bit and 8-bit is > not allowed and can corrupt register content. > > This patch adds omap3_mcbsp_pollwrite and > omap3_mcbsp_pollread functions for OMAP3 cpu, inorder to > perform 32 bit access of above mentioned McBSP registers. How about making the functions generic, I don't think we want to have separate omap1_mcbsp_pollread, omap2_mcbsp_pollread, omap3_mcbsp_pollread.. If it's not obvious how to implement it for some omap, just return an error based on the CPU type. Regards, Tony > Signed-off-by: Charulatha V > Signed-off-by: Syed Rafiuddin > --- > arch/arm/plat-omap/include/mach/mcbsp.h | 4 + > arch/arm/plat-omap/mcbsp.c | 92 ++++++++++++++++++++++++++++++- > 2 files changed, 95 insertions(+), 1 deletions(-) > > diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h b/arch/arm/plat-omap/include/mach/mcbsp.h > index 0c5f937..b0f9260 100644 > --- a/arch/arm/plat-omap/include/mach/mcbsp.h > +++ b/arch/arm/plat-omap/include/mach/mcbsp.h > @@ -406,6 +406,10 @@ void omap_mcbsp_set_spi_mode(unsigned int id, const struct omap_mcbsp_spi_cfg * > /* Polled read/write functions */ > int omap_mcbsp_pollread(unsigned int id, u16 * buf); > int omap_mcbsp_pollwrite(unsigned int id, u16 buf); > + > +int omap3_mcbsp_pollread(unsigned int id, u32 *buf); > +int omap3_mcbsp_pollwrite(unsigned int id, u32 buf); > + > int omap_mcbsp_set_io_type(unsigned int id, omap_mcbsp_io_type_t io_type); > > #endif > diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c > index b6b520d..1212d11 100644 > --- a/arch/arm/plat-omap/mcbsp.c > +++ b/arch/arm/plat-omap/mcbsp.c > @@ -425,7 +425,7 @@ void omap_mcbsp_stop(unsigned int id) > } > EXPORT_SYMBOL(omap_mcbsp_stop); > > -/* polled mcbsp i/o operations */ > +/* polled mcbsp i/o operations for omap1 and omap2420 */ > int omap_mcbsp_pollwrite(unsigned int id, u16 buf) > { > struct omap_mcbsp *mcbsp; > @@ -515,6 +515,96 @@ int omap_mcbsp_pollread(unsigned int id, u16 *buf) > } > EXPORT_SYMBOL(omap_mcbsp_pollread); > > +/* polled mcbsp i/o operations for omap3 */ > +int omap3_mcbsp_pollwrite(unsigned int id, u32 buf) > +{ > + struct omap_mcbsp *mcbsp; > + void __iomem *base; > + > + if (!omap_mcbsp_check_valid_id(id)) { > + printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1); > + return -ENODEV; > + } > + > + mcbsp = id_to_mcbsp_ptr(id); > + base = mcbsp->io_base; > + > + OMAP_MCBSP_WRITE(base, DXR, buf); > + /* if frame sync error - clear the error */ > + if (OMAP_MCBSP_READ(base, SPCR2) & XSYNC_ERR) { > + /* clear error */ > + OMAP_MCBSP_WRITE(base, SPCR2, OMAP_MCBSP_READ(base, SPCR2) > + & (~XSYNC_ERR)); > + /* resend */ > + return -EPERM; > + } else { > + /* wait for transmit confirmation */ > + int attemps = 0; > + while (!(OMAP_MCBSP_READ(base, SPCR2) & XRDY)) { > + if (attemps++ > 1000) { > + OMAP_MCBSP_WRITE(base, SPCR2, > + OMAP_MCBSP_READ(base, SPCR2) & > + (~XRST)); > + udelay(10); > + OMAP_MCBSP_WRITE(base, SPCR2, > + OMAP_MCBSP_READ(base, SPCR2) | > + (XRST)); > + udelay(10); > + dev_err(mcbsp->dev, "Could not write to" > + " McBSP%d Register\n", mcbsp->id); > + return -ENOENT; > + } > + } > + } > + > + return 0; > +} > +EXPORT_SYMBOL(omap3_mcbsp_pollwrite); > + > +int omap3_mcbsp_pollread(unsigned int id, u32 *buf) > +{ > + struct omap_mcbsp *mcbsp; > + void __iomem *base; > + > + if (!omap_mcbsp_check_valid_id(id)) { > + printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1); > + return -ENODEV; > + } > + mcbsp = id_to_mcbsp_ptr(id); > + > + base = mcbsp->io_base; > + /* if frame sync error - clear the error */ > + if (OMAP_MCBSP_READ(base, SPCR1) & RSYNC_ERR) { > + /* clear error */ > + OMAP_MCBSP_WRITE(base, SPCR1, OMAP_MCBSP_READ(base, SPCR1) > + & (~RSYNC_ERR)); > + /* resend */ > + return -EPERM; > + } else { > + /* wait for recieve confirmation */ > + int attemps = 0; > + while (!(OMAP_MCBSP_READ(base, SPCR1) & RRDY)) { > + if (attemps++ > 1000) { > + OMAP_MCBSP_WRITE(base, SPCR1, > + OMAP_MCBSP_READ(base, SPCR1) & > + (~RRST)); > + udelay(10); > + OMAP_MCBSP_WRITE(base, SPCR1, > + OMAP_MCBSP_READ(base, SPCR1) | > + (RRST)); > + udelay(10); > + dev_err(mcbsp->dev, "Could not read from" > + " McBSP%d Register\n", mcbsp->id); > + return -ENOENT; > + } > + } > + } > + *buf = OMAP_MCBSP_READ(base, DRR); > + > + return 0; > +} > +EXPORT_SYMBOL(omap3_mcbsp_pollread); > + > /* > * IRQ based word transmission. > */ > -- > 1.6.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html