commit 3d6271f92e98094584fd1e609a9969cd33e61122
author Kyle Manna <kyle@kylemanna.com> Thu Aug 11 22:33:13 2011 -0500
committer Samuel Ortiz <sameo@linux.intel.com> Mon Oct 24 14:09:10 2011 +0200
tree a3091ebc18edf9a2cef177bace2aea8b0b16d8ea
parent 881de67046f424fc3a6e05b1c681c12afd94e802

mfd: Turn on the twl4030-madc MADC clock

Without turning the MADC clock on, no MADC conversions occur.

$ cat /sys/class/hwmon/hwmon0/device/in8_input
[   53.428436] twl4030_madc twl4030_madc: conversion timeout!
cat: read error: Resource temporarily unavailable

Signed-off-by: Kyle Manna <kyle@kylemanna.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/mfd/twl4030-madc.c

diff --git a/drivers/mfd/twl4030-madc.c b/drivers/mfd/twl4030-madc.c
index 7cbf2aa..834f824 100644
--- a/drivers/mfd/twl4030-madc.c
+++ b/drivers/mfd/twl4030-madc.c
@@ -740,6 +740,28 @@
 			TWL4030_BCI_BCICTL1);
 		goto err_i2c;
 	}
+
+	/* Check that MADC clock is on */
+	ret = twl_i2c_read_u8(TWL4030_MODULE_INTBR, &regval, TWL4030_REG_GPBR1);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to read reg GPBR1 0x%X\n",
+				TWL4030_REG_GPBR1);
+		goto err_i2c;
+	}
+
+	/* If MADC clk is not on, turn it on */
+	if (!(regval & TWL4030_GPBR1_MADC_HFCLK_EN)) {
+		dev_info(&pdev->dev, "clk disabled, enabling\n");
+		regval |= TWL4030_GPBR1_MADC_HFCLK_EN;
+		ret = twl_i2c_write_u8(TWL4030_MODULE_INTBR, regval,
+				       TWL4030_REG_GPBR1);
+		if (ret) {
+			dev_err(&pdev->dev, "unable to write reg GPBR1 0x%X\n",
+					TWL4030_REG_GPBR1);
+			goto err_i2c;
+		}
+	}
+
 	platform_set_drvdata(pdev, madc);
 	mutex_init(&madc->lock);
 	ret = request_threaded_irq(platform_get_irq(pdev, 0), NULL,