mfd: stmpe: Preparations for STMPE ADC driver

This prepares the MFD for the STMPE ADC driver. This commit introduces
devicetree settings that are used by the ADC and adds an init function.
Common ADC settings that are shared with the touchscreen driver can now
reside in the overlying MFD.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Philippe Schenker <philippe.schenker@toradex.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 68 insertions, 0 deletions

diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index 566caca4efd8..f582531a8f3e 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -464,6 +464,28 @@ static const struct mfd_cell stmpe_ts_cell = {
 };
 
 /*
+ * ADC (STMPE811)
+ */
+
+static struct resource stmpe_adc_resources[] = {
+	{
+		.name	= "STMPE_TEMP_SENS",
+		.flags	= IORESOURCE_IRQ,
+	},
+	{
+		.name	= "STMPE_ADC",
+		.flags	= IORESOURCE_IRQ,
+	},
+};
+
+static const struct mfd_cell stmpe_adc_cell = {
+	.name		= "stmpe-adc",
+	.of_compatible	= "st,stmpe-adc",
+	.resources	= stmpe_adc_resources,
+	.num_resources	= ARRAY_SIZE(stmpe_adc_resources),
+};
+
+/*
  * STMPE811 or STMPE610
  */
 
@@ -497,6 +519,11 @@ static struct stmpe_variant_block stmpe811_blocks[] = {
 		.irq	= STMPE811_IRQ_TOUCH_DET,
 		.block	= STMPE_BLOCK_TOUCHSCREEN,
 	},
+	{
+		.cell	= &stmpe_adc_cell,
+		.irq	= STMPE811_IRQ_TEMP_SENS,
+		.block	= STMPE_BLOCK_ADC,
+	},
 };
 
 static int stmpe811_enable(struct stmpe *stmpe, unsigned int blocks,
@@ -517,6 +544,35 @@ static int stmpe811_enable(struct stmpe *stmpe, unsigned int blocks,
 				enable ? 0 : mask);
 }
 
+int stmpe811_adc_common_init(struct stmpe *stmpe)
+{
+	int ret;
+	u8 adc_ctrl1, adc_ctrl1_mask;
+
+	adc_ctrl1 = STMPE_SAMPLE_TIME(stmpe->sample_time) |
+		    STMPE_MOD_12B(stmpe->mod_12b) |
+		    STMPE_REF_SEL(stmpe->ref_sel);
+	adc_ctrl1_mask = STMPE_SAMPLE_TIME(0xff) | STMPE_MOD_12B(0xff) |
+			 STMPE_REF_SEL(0xff);
+
+	ret = stmpe_set_bits(stmpe, STMPE811_REG_ADC_CTRL1,
+			adc_ctrl1_mask, adc_ctrl1);
+	if (ret) {
+		dev_err(stmpe->dev, "Could not setup ADC\n");
+		return ret;
+	}
+
+	ret = stmpe_set_bits(stmpe, STMPE811_REG_ADC_CTRL2,
+			STMPE_ADC_FREQ(0xff), STMPE_ADC_FREQ(stmpe->adc_freq));
+	if (ret) {
+		dev_err(stmpe->dev, "Could not setup ADC\n");
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(stmpe811_adc_common_init);
+
 static int stmpe811_get_altfunc(struct stmpe *stmpe, enum stmpe_block block)
 {
 	/* 0 for touchscreen, 1 for GPIO */
@@ -1325,6 +1381,7 @@ int stmpe_probe(struct stmpe_client_info *ci, enum stmpe_partnum partnum)
 	struct device_node *np = ci->dev->of_node;
 	struct stmpe *stmpe;
 	int ret;
+	u32 val;
 
 	pdata = devm_kzalloc(ci->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
@@ -1342,6 +1399,15 @@ int stmpe_probe(struct stmpe_client_info *ci, enum stmpe_partnum partnum)
 	mutex_init(&stmpe->irq_lock);
 	mutex_init(&stmpe->lock);
 
+	if (!of_property_read_u32(np, "st,sample-time", &val))
+		stmpe->sample_time = val;
+	if (!of_property_read_u32(np, "st,mod-12b", &val))
+		stmpe->mod_12b = val;
+	if (!of_property_read_u32(np, "st,ref-sel", &val))
+		stmpe->ref_sel = val;
+	if (!of_property_read_u32(np, "st,adc-freq", &val))
+		stmpe->adc_freq = val;
+
 	stmpe->dev = ci->dev;
 	stmpe->client = ci->client;
 	stmpe->pdata = pdata;
@@ -1433,6 +1499,8 @@ int stmpe_remove(struct stmpe *stmpe)
 	if (!IS_ERR(stmpe->vcc))
 		regulator_disable(stmpe->vcc);
 
+	__stmpe_disable(stmpe, STMPE_BLOCK_ADC);
+
 	mfd_remove_devices(stmpe->dev);
 
 	return 0;