On Mon, Jan 11, 2010 at 6:30 PM, Grazvydas Ignotas notasas@gmail.com wrote:
On Sat, Jan 9, 2010 at 6:42 AM, Khasim Syed Mohammed khasim@beagleboard.org wrote:
From cc1b24cb290d428f2e1aefec9c7878b46380f592 Mon Sep 17 00:00:00 2001 From: Syed Mohammed Khasim khasim@ti.com Date: Sat, 9 Jan 2010 09:28:03 +0530 Subject: [PATCH] API to select twl4030 voltage and dev group
Adds a new API "twl4030_pmrecv_vsel_cfg" to select voltage and its device group
Signed-off-by: Syed Mohammed Khasim khasim@ti.com
<snip>
@@ -113,3 +104,18 @@ void twl4030_power_mmc_init(void) twl4030_i2c_write_u8(TWL4030_CHIP_PM_RECEIVER, byte, TWL4030_PM_RECEIVER_VMMC1_DEDICATED); }
+/*
- Generic function to select Device Group and Voltage
- */
+void twl4030_pmrecv_vsel_cfg(u8 vsel_reg, u8 vsel_val,
- u8 dev_grp, u8 dev_grp_sel)
+{
- /* Select the Device Group */
- twl4030_i2c_write_u8(TWL4030_CHIP_PM_RECEIVER, dev_grp_sel,
- dev_grp);
- /* Select the Voltage */
- twl4030_i2c_write_u8(TWL4030_CHIP_PM_RECEIVER, vsel_val,
- vsel_reg);
+}
I was always wondering why TI code first sets the device group (which effectively enables the supply), and configures voltage after that. Doesn't that cause wrong voltage output for a short interval of time (knowing that i2c transfers take some time to complete)? What happens if second write fails due to some i2c error?
Good / Wonderful Catch, I will correct them in my patch.
Regards, Khasim