dm: adc: add simple ADC uclass implementation
This commit adds:
- new uclass id: UCLASS_ADC
- new uclass driver: drivers/adc/adc-uclass.c
The new uclass's API allows for ADC operation on:
* single-channel with channel selection by a number
* multti-channel with channel selection by bit mask
ADC uclass's functions:
* single-channel:
- adc_start_channel() - start channel conversion
- adc_channel_data() - get conversion data
- adc_channel_single_shot() - start/get conversion data
* multi-channel:
- adc_start_channels() - start selected channels conversion
- adc_channels_data() - get conversion data
- adc_channels_single_shot() - start/get conversion data for channels
selected by bit mask
* general:
- adc_stop() - stop the conversion
- adc_vdd_value() - positive reference Voltage value with polarity [uV]
- adc_vss_value() - negative reference Voltage value with polarity [uV]
- adc_data_mask() - conversion data bit mask
The device tree can provide below constraints/properties:
- vdd-polarity-negative: if true: Vdd = vdd-microvolts * (-1)
- vss-polarity-negative: if true: Vss = vss-microvolts * (-1)
- vdd-supply: phandle to Vdd regulator's node
- vss-supply: phandle to Vss regulator's node
And optional, checked only if the above corresponding, doesn't exist:
- vdd-microvolts: positive reference Voltage [uV]
- vss-microvolts: negative reference Voltage [uV]
Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/drivers/adc/Kconfig b/drivers/adc/Kconfig
new file mode 100644
index 0000000..b6e226a
--- /dev/null
+++ b/drivers/adc/Kconfig
@@ -0,0 +1,12 @@
+config ADC
+ bool "Enable ADC drivers using Driver Model"
+ help
+ This enables ADC API for drivers, which allows driving ADC features
+ by single and multi-channel methods for:
+ - start/stop/get data for conversion of a single-channel selected by
+ a number or multi-channels selected by a bitmask
+ - get data mask (ADC resolution)
+ ADC reference Voltage supply options:
+ - methods for get Vdd/Vss reference Voltage values with polarity
+ - support supply's phandle with auto-enable
+ - supply polarity setting in fdt
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@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..9233fcd
--- /dev/null
+++ b/drivers/adc/adc-uclass.c
@@ -0,0 +1,409 @@
+/*
+ * Copyright (C) 2015 Samsung Electronics
+ * Przemyslaw Marczak <p.marczak@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>
+#include <power/regulator.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define ADC_UCLASS_PLATDATA_SIZE sizeof(struct adc_uclass_platdata)
+#define CHECK_NUMBER true
+#define CHECK_MASK (!CHECK_NUMBER)
+
+/* TODO: add support for timer uclass (for early calls) */
+#ifdef CONFIG_SANDBOX_ARCH
+#define sdelay(x) udelay(x)
+#else
+extern void sdelay(unsigned long loops);
+#endif
+
+static int check_channel(struct udevice *dev, int value, bool number_or_mask,
+ const char *caller_function)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ unsigned mask = number_or_mask ? (1 << value) : value;
+
+ /* For the real ADC hardware, some ADC channels can be inactive.
+ * For example if device has 4 analog channels, and only channels
+ * 1-st and 3-rd are valid, then channel mask is: 0b1010, so request
+ * with mask 0b1110 should return an error.
+ */
+ if ((uc_pdata->channel_mask >= mask) && (uc_pdata->channel_mask & mask))
+ return 0;
+
+ printf("Error in %s/%s().\nWrong channel selection for device: %s\n",
+ __FILE__, caller_function, dev->name);
+
+ return -EINVAL;
+}
+
+static int adc_supply_enable(struct udevice *dev)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ const char *supply_type;
+ int ret = 0;
+
+ if (uc_pdata->vdd_supply) {
+ supply_type = "vdd";
+ ret = regulator_set_enable(uc_pdata->vdd_supply, true);
+ }
+
+ if (!ret && uc_pdata->vss_supply) {
+ supply_type = "vss";
+ ret = regulator_set_enable(uc_pdata->vss_supply, true);
+ }
+
+ if (ret)
+ error("%s: can't enable %s-supply!", dev->name, supply_type);
+
+ return ret;
+}
+
+int adc_data_mask(struct udevice *dev, unsigned int *data_mask)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+
+ if (!uc_pdata)
+ return -ENOSYS;
+
+ *data_mask = uc_pdata->data_mask;
+ return 0;
+}
+
+int adc_stop(struct udevice *dev)
+{
+ const struct adc_ops *ops = dev_get_driver_ops(dev);
+
+ if (!ops->stop)
+ return -ENOSYS;
+
+ return ops->stop(dev);
+}
+
+int adc_start_channel(struct udevice *dev, int channel)
+{
+ const struct adc_ops *ops = dev_get_driver_ops(dev);
+ int ret;
+
+ if (!ops->start_channel)
+ return -ENOSYS;
+
+ ret = check_channel(dev, channel, CHECK_NUMBER, __func__);
+ if (ret)
+ return ret;
+
+ ret = adc_supply_enable(dev);
+ if (ret)
+ return ret;
+
+ return ops->start_channel(dev, channel);
+}
+
+int adc_start_channels(struct udevice *dev, unsigned int channel_mask)
+{
+ const struct adc_ops *ops = dev_get_driver_ops(dev);
+ int ret;
+
+ if (!ops->start_channels)
+ return -ENOSYS;
+
+ ret = check_channel(dev, channel_mask, CHECK_MASK, __func__);
+ if (ret)
+ return ret;
+
+ ret = adc_supply_enable(dev);
+ if (ret)
+ return ret;
+
+ return ops->start_channels(dev, channel_mask);
+}
+
+int adc_channel_data(struct udevice *dev, int channel, unsigned int *data)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ const struct adc_ops *ops = dev_get_driver_ops(dev);
+ unsigned int timeout_us = uc_pdata->data_timeout_us;
+ int ret;
+
+ if (!ops->channel_data)
+ return -ENOSYS;
+
+ ret = check_channel(dev, channel, CHECK_NUMBER, __func__);
+ if (ret)
+ return ret;
+
+ do {
+ ret = ops->channel_data(dev, channel, data);
+ if (!ret || ret != -EBUSY)
+ break;
+
+ /* TODO: use timer uclass (for early calls). */
+ sdelay(5);
+ } while (timeout_us--);
+
+ return ret;
+}
+
+int adc_channels_data(struct udevice *dev, unsigned int channel_mask,
+ struct adc_channel *channels)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ unsigned int timeout_us = uc_pdata->multidata_timeout_us;
+ const struct adc_ops *ops = dev_get_driver_ops(dev);
+ int ret;
+
+ if (!ops->channels_data)
+ return -ENOSYS;
+
+ ret = check_channel(dev, channel_mask, CHECK_MASK, __func__);
+ if (ret)
+ return ret;
+
+ do {
+ ret = ops->channels_data(dev, channel_mask, channels);
+ if (!ret || ret != -EBUSY)
+ break;
+
+ /* TODO: use timer uclass (for early calls). */
+ sdelay(5);
+ } while (timeout_us--);
+
+ return ret;
+}
+
+int adc_channel_single_shot(const char *name, int channel, unsigned int *data)
+{
+ struct udevice *dev;
+ int ret;
+
+ ret = uclass_get_device_by_name(UCLASS_ADC, name, &dev);
+ if (ret)
+ return ret;
+
+ ret = adc_start_channel(dev, channel);
+ if (ret)
+ return ret;
+
+ ret = adc_channel_data(dev, channel, data);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int _adc_channels_single_shot(struct udevice *dev,
+ unsigned int channel_mask,
+ struct adc_channel *channels)
+{
+ unsigned int data;
+ int channel, ret;
+
+ for (channel = 0; channel <= ADC_MAX_CHANNEL; channel++) {
+ /* Check channel bit. */
+ if (!((channel_mask >> channel) & 0x1))
+ continue;
+
+ ret = adc_start_channel(dev, channel);
+ if (ret)
+ return ret;
+
+ ret = adc_channel_data(dev, channel, &data);
+ if (ret)
+ return ret;
+
+ channels->id = channel;
+ channels->data = data;
+ channels++;
+ }
+
+ return 0;
+}
+
+int adc_channels_single_shot(const char *name, unsigned int channel_mask,
+ struct adc_channel *channels)
+{
+ struct udevice *dev;
+ int ret;
+
+ ret = uclass_get_device_by_name(UCLASS_ADC, name, &dev);
+ if (ret)
+ return ret;
+
+ ret = adc_start_channels(dev, channel_mask);
+ if (ret)
+ goto try_manual;
+
+ ret = adc_channels_data(dev, channel_mask, channels);
+ if (ret)
+ return ret;
+
+ return 0;
+
+try_manual:
+ if (ret != -ENOSYS)
+ return ret;
+
+ return _adc_channels_single_shot(dev, channel_mask, channels);
+}
+
+static int adc_vdd_platdata_update(struct udevice *dev)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ int ret;
+
+ /* Warning!
+ * This function can't return supply device before its bind.
+ * Please pay attention to proper fdt scan sequence. If ADC device
+ * will bind before its supply regulator device, then the below 'get'
+ * will return an error.
+ */
+ ret = device_get_supply_regulator(dev, "vdd-supply",
+ &uc_pdata->vdd_supply);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_value(uc_pdata->vdd_supply);
+ if (ret < 0)
+ return ret;
+
+ uc_pdata->vdd_microvolts = ret;
+
+ return 0;
+}
+
+static int adc_vss_platdata_update(struct udevice *dev)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ int ret;
+
+ ret = device_get_supply_regulator(dev, "vss-supply",
+ &uc_pdata->vss_supply);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_value(uc_pdata->vss_supply);
+ if (ret < 0)
+ return ret;
+
+ uc_pdata->vss_microvolts = ret;
+
+ return 0;
+}
+
+int adc_vdd_value(struct udevice *dev, int *uV)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ int ret, value_sign = uc_pdata->vdd_polarity_negative ? -1 : 1;
+
+ if (!uc_pdata->vdd_supply)
+ goto nodev;
+
+ /* Update the regulator Value. */
+ ret = adc_vdd_platdata_update(dev);
+ if (ret)
+ return ret;
+nodev:
+ if (uc_pdata->vdd_microvolts == -ENODATA)
+ return -ENODATA;
+
+ *uV = uc_pdata->vdd_microvolts * value_sign;
+
+ return 0;
+}
+
+int adc_vss_value(struct udevice *dev, int *uV)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ int ret, value_sign = uc_pdata->vss_polarity_negative ? -1 : 1;
+
+ if (!uc_pdata->vss_supply)
+ goto nodev;
+
+ /* Update the regulator Value. */
+ ret = adc_vss_platdata_update(dev);
+ if (ret)
+ return ret;
+nodev:
+ if (uc_pdata->vss_microvolts == -ENODATA)
+ return -ENODATA;
+
+ *uV = uc_pdata->vss_microvolts * value_sign;
+
+ return 0;
+}
+
+static int adc_vdd_platdata_set(struct udevice *dev)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ int ret, offset = dev->of_offset;
+ const void *fdt = gd->fdt_blob;
+ char *prop;
+
+ prop = "vdd-polarity-negative";
+ uc_pdata->vdd_polarity_negative = fdtdec_get_bool(fdt, offset, prop);
+
+ ret = adc_vdd_platdata_update(dev);
+ if (ret != -ENOENT)
+ return ret;
+
+ /* No vdd-supply phandle. */
+ prop = "vdd-microvolts";
+ uc_pdata->vdd_microvolts = fdtdec_get_int(fdt, offset, prop, -ENODATA);
+
+ return 0;
+}
+
+static int adc_vss_platdata_set(struct udevice *dev)
+{
+ struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+ int ret, offset = dev->of_offset;
+ const void *fdt = gd->fdt_blob;
+ char *prop;
+
+ prop = "vss-polarity-negative";
+ uc_pdata->vss_polarity_negative = fdtdec_get_bool(fdt, offset, prop);
+
+ ret = adc_vss_platdata_update(dev);
+ if (ret != -ENOENT)
+ return ret;
+
+ /* No vss-supply phandle. */
+ prop = "vss-microvolts";
+ uc_pdata->vss_microvolts = fdtdec_get_int(fdt, offset, prop, -ENODATA);
+
+ return 0;
+}
+
+static int adc_pre_probe(struct udevice *dev)
+{
+ int ret;
+
+ /* Set ADC VDD platdata: polarity, uV, regulator (phandle). */
+ ret = adc_vdd_platdata_set(dev);
+ if (ret)
+ error("%s: Can't update Vdd. Error: %d", dev->name, ret);
+
+ /* Set ADC VSS platdata: polarity, uV, regulator (phandle). */
+ ret = adc_vss_platdata_set(dev);
+ if (ret)
+ error("%s: Can't update Vss. Error: %d", dev->name, ret);
+
+ return 0;
+}
+
+UCLASS_DRIVER(adc) = {
+ .id = UCLASS_ADC,
+ .name = "adc",
+ .pre_probe = adc_pre_probe,
+ .per_device_platdata_auto_alloc_size = ADC_UCLASS_PLATDATA_SIZE,
+};