From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: new alsa driver for ti omap chip Date: Thu, 12 Feb 2004 11:58:11 +0100 Sender: alsa-devel-admin@lists.sourceforge.net Message-ID: References: Mime-Version: 1.0 (generated by SEMI 1.14.5 - "Awara-Onsen") Content-Type: text/plain; charset=US-ASCII Return-path: In-Reply-To: Errors-To: alsa-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: "Gupta, Kshitij" Cc: "'alsa-devel@lists.sourceforge.net'" List-Id: alsa-devel@alsa-project.org At Thu, 12 Feb 2004 12:56:04 +0530, Gupta, Kshitij wrote: > > hi, > > I am trying to write an alsa driver for a tsc2101 codec on a arm > based SOC. The control interface between the SOC and the tsc2101 codec is > via SPI. > And the data interface is a I2S interface. Can some one suggest a good > starting point to start such a driver. some ALSA drivers use their own i2c functions, although there is a generic i2c layer on linux kernel. for example, delta.c or ews.c of ice1712 driver use i2c (SPI) transfer (which calls ak4xxx-adda.c). but it's rather complex to refer... the i2c transfer is really easy to implement. do just like the spec says. a pseudo code is like below. chip_select_low(); udelay(1); for (i = 15; i >= 0; i--) { set_bit_clock(0); udelay(1); if (value_to_send & (1 << i)) set_bit_data(1); else set_bit_data(0); udelay(1); set_bit_clock(0); udelay(1); } chip_select_high(); > does sound/drivers/dummy.c makes sense for such a driver ??? the dummy driver is irrelevant to the BUS type, so it makes some sense to read the code :) Takashi ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click