From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: [PATCH 09/11] omap: McBSP: Do not enable SRG in slave mode Date: Thu, 23 Sep 2010 18:51:07 -0700 Message-ID: <20100924015107.10325.41789.stgit@baageli.muru.com> References: <20100924014938.10325.35279.stgit@baageli.muru.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:57763 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756539Ab0IXBvH (ORCPT ); Thu, 23 Sep 2010 21:51:07 -0400 In-Reply-To: <20100924014938.10325.35279.stgit@baageli.muru.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-arm-kernel@lists.infradead.org Cc: Jarkko Nikula , linux-omap@vger.kernel.org, Peter Ujfalusi From: Peter Ujfalusi McBSP SRG (Sample Rate Generator) and FSG (Frame Sync Generator) is only needed to be enabled, when McBSP is master. In McBSP slave mode, the SRG, and FSG can be kept disabled, which might save some power at the end in this configuration. Signed-off-by: Peter Ujfalusi Acked-by: Jarkko Nikula Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/mcbsp.c | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c index e31496e..ecbfe39 100644 --- a/arch/arm/plat-omap/mcbsp.c +++ b/arch/arm/plat-omap/mcbsp.c @@ -878,7 +878,7 @@ EXPORT_SYMBOL(omap_mcbsp_free); void omap_mcbsp_start(unsigned int id, int tx, int rx) { struct omap_mcbsp *mcbsp; - int idle; + int enable_srg = 0; u16 w; if (!omap_mcbsp_check_valid_id(id)) { @@ -893,10 +893,13 @@ void omap_mcbsp_start(unsigned int id, int tx, int rx) mcbsp->rx_word_length = (MCBSP_READ_CACHE(mcbsp, RCR1) >> 5) & 0x7; mcbsp->tx_word_length = (MCBSP_READ_CACHE(mcbsp, XCR1) >> 5) & 0x7; - idle = !((MCBSP_READ_CACHE(mcbsp, SPCR2) | - MCBSP_READ_CACHE(mcbsp, SPCR1)) & 1); + /* Only enable SRG, if McBSP is master */ + w = MCBSP_READ_CACHE(mcbsp, PCR0); + if (w & (FSXM | FSRM | CLKXM | CLKRM)) + enable_srg = !((MCBSP_READ_CACHE(mcbsp, SPCR2) | + MCBSP_READ_CACHE(mcbsp, SPCR1)) & 1); - if (idle) { + if (enable_srg) { /* Start the sample generator */ w = MCBSP_READ_CACHE(mcbsp, SPCR2); MCBSP_WRITE(mcbsp, SPCR2, w | (1 << 6)); @@ -919,7 +922,7 @@ void omap_mcbsp_start(unsigned int id, int tx, int rx) */ udelay(500); - if (idle) { + if (enable_srg) { /* Start frame sync */ w = MCBSP_READ_CACHE(mcbsp, SPCR2); MCBSP_WRITE(mcbsp, SPCR2, w | (1 << 7)); From mboxrd@z Thu Jan 1 00:00:00 1970 From: tony@atomide.com (Tony Lindgren) Date: Thu, 23 Sep 2010 18:51:07 -0700 Subject: [PATCH 09/11] omap: McBSP: Do not enable SRG in slave mode In-Reply-To: <20100924014938.10325.35279.stgit@baageli.muru.com> References: <20100924014938.10325.35279.stgit@baageli.muru.com> Message-ID: <20100924015107.10325.41789.stgit@baageli.muru.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Peter Ujfalusi McBSP SRG (Sample Rate Generator) and FSG (Frame Sync Generator) is only needed to be enabled, when McBSP is master. In McBSP slave mode, the SRG, and FSG can be kept disabled, which might save some power at the end in this configuration. Signed-off-by: Peter Ujfalusi Acked-by: Jarkko Nikula Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/mcbsp.c | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c index e31496e..ecbfe39 100644 --- a/arch/arm/plat-omap/mcbsp.c +++ b/arch/arm/plat-omap/mcbsp.c @@ -878,7 +878,7 @@ EXPORT_SYMBOL(omap_mcbsp_free); void omap_mcbsp_start(unsigned int id, int tx, int rx) { struct omap_mcbsp *mcbsp; - int idle; + int enable_srg = 0; u16 w; if (!omap_mcbsp_check_valid_id(id)) { @@ -893,10 +893,13 @@ void omap_mcbsp_start(unsigned int id, int tx, int rx) mcbsp->rx_word_length = (MCBSP_READ_CACHE(mcbsp, RCR1) >> 5) & 0x7; mcbsp->tx_word_length = (MCBSP_READ_CACHE(mcbsp, XCR1) >> 5) & 0x7; - idle = !((MCBSP_READ_CACHE(mcbsp, SPCR2) | - MCBSP_READ_CACHE(mcbsp, SPCR1)) & 1); + /* Only enable SRG, if McBSP is master */ + w = MCBSP_READ_CACHE(mcbsp, PCR0); + if (w & (FSXM | FSRM | CLKXM | CLKRM)) + enable_srg = !((MCBSP_READ_CACHE(mcbsp, SPCR2) | + MCBSP_READ_CACHE(mcbsp, SPCR1)) & 1); - if (idle) { + if (enable_srg) { /* Start the sample generator */ w = MCBSP_READ_CACHE(mcbsp, SPCR2); MCBSP_WRITE(mcbsp, SPCR2, w | (1 << 6)); @@ -919,7 +922,7 @@ void omap_mcbsp_start(unsigned int id, int tx, int rx) */ udelay(500); - if (idle) { + if (enable_srg) { /* Start frame sync */ w = MCBSP_READ_CACHE(mcbsp, SPCR2); MCBSP_WRITE(mcbsp, SPCR2, w | (1 << 7));