[PATCH v3] davinci: Add wl1271/wlan support for AM18x
From: Ido Yariv <hidden>
Date: 2011-07-28 22:06:43
Also in:
linux-mmc
From: Ido Yariv <hidden>
Date: 2011-07-28 22:06:43
Also in:
linux-mmc
Hi Troy, On Thu, Jul 28, 2011 at 02:15:41PM -0700, Troy Kisky wrote:
quoted
+ if (power_on) { + /* Power up sequence required for wl127x devices */ + gpio_set_value(DA850_WLAN_EN, 1); + usleep_range(15000, 15000); + gpio_set_value(DA850_WLAN_EN, 0); + usleep_range(1000, 1000); + gpio_set_value(DA850_WLAN_EN, 1); + msleep(70);Why turn on, then off, and then back on? Isn't off, then back on sufficient?
Unfortunately, no. This is a required power up sequence for some hardware revisions of the 1271 chip.
Also, why not use regulator API like panda board does?
Unlike omap_hsmmc, davinci's MMC host driver does not toggle any regulators. To keep things simple, a set_power callback function was added to the mmc host as part of this patch series. I've considered adding regulator support instead, but found it to be a bit over-complicated for this task. In addition, it would require either modifying the fixed regulator or adding a new one in order to support the above power sequence. Thanks for your review, Ido.