[U-Boot] [PATCH V2 06/11] dm: adc: add simple ADC uclass implementation

Przemyslaw Marczak p.marczak at samsung.com
Mon Sep 21 14:26:38 CEST 2015


This commit adds:
- new uclass id: UCLASS_ADC
- new uclass driver: drivers/adc/adc-uclass.c

The uclass's implementation is as simple as needed and provides functions:
- adc_init() - init ADC conversion
- adc_data() - convert and return data
- adc_data_mask() - return ADC data mask
- adc_channel_single_shot() - function for single ADC convertion

Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
---
Changes V2:
- new commit - introduce ADC uclass driver
---
 drivers/Kconfig          |  2 ++
 drivers/Makefile         |  1 +
 drivers/adc/Kconfig      |  8 +++++
 drivers/adc/Makefile     |  8 +++++
 drivers/adc/adc-uclass.c | 76 +++++++++++++++++++++++++++++++++++++++++
 include/adc.h            | 88 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/dm/uclass-id.h   |  1 +
 7 files changed, 184 insertions(+)
 create mode 100644 drivers/adc/Kconfig
 create mode 100644 drivers/adc/Makefile
 create mode 100644 drivers/adc/adc-uclass.c
 create mode 100644 include/adc.h

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 63c92c5..ad9ae3a 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -4,6 +4,8 @@ source "drivers/core/Kconfig"
 
 # types of drivers sorted in alphabetical order
 
+source "drivers/adc/Kconfig"
+
 source "drivers/block/Kconfig"
 
 source "drivers/clk/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 9d0a595..d7d5e9f 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_SPL_SATA_SUPPORT) += block/
 
 else
 
+obj-y += adc/
 obj-$(CONFIG_DM_DEMO) += demo/
 obj-$(CONFIG_BIOSEMU) += bios_emulator/
 obj-y += block/
diff --git a/drivers/adc/Kconfig b/drivers/adc/Kconfig
new file mode 100644
index 0000000..1cb1a8d
--- /dev/null
+++ b/drivers/adc/Kconfig
@@ -0,0 +1,8 @@
+config ADC
+	bool "Enable ADC drivers using Driver Model"
+	help
+	  This allows drivers to be provided for ADCs to drive their features,
+	  trough simple ADC uclass driver interface, with operations:
+	  - device enable
+	  - conversion init
+	  - conversion start and return data with data mask
diff --git a/drivers/adc/Makefile b/drivers/adc/Makefile
new file mode 100644
index 0000000..c4d9618
--- /dev/null
+++ b/drivers/adc/Makefile
@@ -0,0 +1,8 @@
+#
+# Copyright (C) 2015 Samsung Electronics
+# Przemyslaw Marczak <p.marczak at samsung.com>
+#
+# SPDX-License-Identifier:     GPL-2.0+
+#
+
+obj-$(CONFIG_ADC) += adc-uclass.o
diff --git a/drivers/adc/adc-uclass.c b/drivers/adc/adc-uclass.c
new file mode 100644
index 0000000..bb71b6e
--- /dev/null
+++ b/drivers/adc/adc-uclass.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2015 Samsung Electronics
+ * Przemyslaw Marczak <p.marczak at samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <dm.h>
+#include <dm/lists.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+#include <adc.h>
+
+#define ADC_UCLASS_PLATDATA_SIZE	sizeof(struct adc_uclass_platdata)
+
+int adc_init(struct udevice *dev, int channel)
+{
+	const struct adc_ops *ops = dev_get_driver_ops(dev);
+
+	if (ops->adc_init)
+		return ops->adc_init(dev, channel);
+
+	return -ENOSYS;
+}
+
+int adc_data(struct udevice *dev, unsigned int *data)
+{
+	const struct adc_ops *ops = dev_get_driver_ops(dev);
+
+	*data = 0;
+
+	if (ops->adc_data)
+		return ops->adc_data(dev, data);
+
+	return -ENOSYS;
+}
+
+int adc_data_mask(struct udevice *dev)
+{
+	struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+
+	if (uc_pdata)
+		return uc_pdata->data_mask;
+
+	return -ENOSYS;
+}
+
+int adc_channel_single_shot(const char *name, int channel, unsigned int *data)
+{
+	struct udevice *dev;
+	int ret;
+
+	*data = 0;
+
+	ret = uclass_get_device_by_name(UCLASS_ADC, name, &dev);
+	if (ret)
+		return ret;
+
+	ret = adc_init(dev, channel);
+	if (ret)
+		return ret;
+
+	ret = adc_data(dev, data);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+UCLASS_DRIVER(adc) = {
+	.id	= UCLASS_ADC,
+	.name	= "adc",
+	.per_device_platdata_auto_alloc_size = ADC_UCLASS_PLATDATA_SIZE,
+};
diff --git a/include/adc.h b/include/adc.h
new file mode 100644
index 0000000..57b9281
--- /dev/null
+++ b/include/adc.h
@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2015 Samsung Electronics
+ * Przemyslaw Marczak <p.marczak at samsung.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _ADC_H_
+#define _ADC_H_
+
+/**
+ * struct adc_uclass_platdata - ADC power supply and reference Voltage info
+ *
+ * @data_mask     - conversion output data mask
+ * @channels_num  - number of analog channels input
+ * @vdd_supply    - positive reference voltage supply
+ * @vss_supply    - negative reference voltage supply
+ */
+struct adc_uclass_platdata {
+	unsigned int data_mask;
+	unsigned int channels_num;
+	struct udevice *vdd_supply;
+	struct udevice *vss_supply;
+};
+
+/**
+ * struct adc_ops - ADC device operations
+ */
+struct adc_ops {
+	/**
+	 * conversion_init() - init device's default conversion parameters
+	 *
+	 * @dev:     ADC device to init
+	 * @channel: analog channel number
+	 * @return:  0 if OK, -ve on error
+	 */
+	int (*adc_init)(struct udevice *dev, int channel);
+
+	/**
+	 * conversion_data() - get output data of given channel conversion
+	 *
+	 * @dev:          ADC device to trigger
+	 * @channel_data: pointer to returned channel's data
+	 * @return:       0 if OK, -ve on error
+	 */
+	int (*adc_data)(struct udevice *dev, unsigned int *channel_data);
+};
+
+/**
+ * adc_init() - init device's default conversion parameters for the given
+ * analog input channel.
+ *
+ * @dev:     ADC device to init
+ * @channel: analog channel number
+ * @return:  0 if OK, -ve on error
+ */
+int adc_init(struct udevice *dev, int channel);
+
+/**
+ * adc_data() - get conversion data for the channel inited by adc_init().
+ *
+ * @dev:    ADC device to trigger
+ * @data:   pointer to returned channel's data
+ * @return: 0 if OK, -ve on error
+ */
+int adc_data(struct udevice *dev, unsigned int *data);
+
+/**
+ * adc_data_mask() - get data mask (ADC resolution mask) for given ADC device.
+ * This can be used if adc uclass platform data is filled.
+ *
+ * @dev:    ADC device to check
+ * @return: 0 if OK, -ve on error
+ */
+int adc_data_mask(struct udevice *dev);
+
+/**
+ * adc_channel_single_shot() - get output data of convertion for the ADC
+ * device's channel. This function search for the device with the given name,
+ * init the given channel and returns the convertion data.
+ *
+ * @name:    device's name to search
+ * @channel: device's input channel to init
+ * @data:    pointer to convertion output data
+ */
+int adc_channel_single_shot(const char *name, int channel, unsigned int *data);
+
+#endif
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 1eeec74..0f7e7da 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -25,6 +25,7 @@ enum uclass_id {
 	UCLASS_SIMPLE_BUS,	/* bus with child devices */
 
 	/* U-Boot uclasses start here - in alphabetical order */
+	UCLASS_ADC,		/* Analog-to-digital converter */
 	UCLASS_CLK,		/* Clock source, e.g. used by peripherals */
 	UCLASS_CPU,		/* CPU, typically part of an SoC */
 	UCLASS_CROS_EC,		/* Chrome OS EC */
-- 
1.9.1



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