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path: root/drivers/iio/adc/mt6577_auxadc.c
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Diffstat (limited to 'drivers/iio/adc/mt6577_auxadc.c')
-rw-r--r--drivers/iio/adc/mt6577_auxadc.c291
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/iio/adc/mt6577_auxadc.c b/drivers/iio/adc/mt6577_auxadc.c
new file mode 100644
index 000000000000..2d104c828041
--- /dev/null
+++ b/drivers/iio/adc/mt6577_auxadc.c
@@ -0,0 +1,291 @@
+/*
+ * Copyright (c) 2016 MediaTek Inc.
+ * Author: Zhiyong Tao <zhiyong.tao@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/iopoll.h>
+#include <linux/io.h>
+#include <linux/iio/iio.h>
+
+/* Register definitions */
+#define MT6577_AUXADC_CON0 0x00
+#define MT6577_AUXADC_CON1 0x04
+#define MT6577_AUXADC_CON2 0x10
+#define MT6577_AUXADC_STA BIT(0)
+
+#define MT6577_AUXADC_DAT0 0x14
+#define MT6577_AUXADC_RDY0 BIT(12)
+
+#define MT6577_AUXADC_MISC 0x94
+#define MT6577_AUXADC_PDN_EN BIT(14)
+
+#define MT6577_AUXADC_DAT_MASK 0xfff
+#define MT6577_AUXADC_SLEEP_US 1000
+#define MT6577_AUXADC_TIMEOUT_US 10000
+#define MT6577_AUXADC_POWER_READY_MS 1
+#define MT6577_AUXADC_SAMPLE_READY_US 25
+
+struct mt6577_auxadc_device {
+ void __iomem *reg_base;
+ struct clk *adc_clk;
+ struct mutex lock;
+};
+
+#define MT6577_AUXADC_CHANNEL(idx) { \
+ .type = IIO_VOLTAGE, \
+ .indexed = 1, \
+ .channel = (idx), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
+}
+
+static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
+ MT6577_AUXADC_CHANNEL(0),
+ MT6577_AUXADC_CHANNEL(1),
+ MT6577_AUXADC_CHANNEL(2),
+ MT6577_AUXADC_CHANNEL(3),
+ MT6577_AUXADC_CHANNEL(4),
+ MT6577_AUXADC_CHANNEL(5),
+ MT6577_AUXADC_CHANNEL(6),
+ MT6577_AUXADC_CHANNEL(7),
+ MT6577_AUXADC_CHANNEL(8),
+ MT6577_AUXADC_CHANNEL(9),
+ MT6577_AUXADC_CHANNEL(10),
+ MT6577_AUXADC_CHANNEL(11),
+ MT6577_AUXADC_CHANNEL(12),
+ MT6577_AUXADC_CHANNEL(13),
+ MT6577_AUXADC_CHANNEL(14),
+ MT6577_AUXADC_CHANNEL(15),
+};
+
+static inline void mt6577_auxadc_mod_reg(void __iomem *reg,
+ u32 or_mask, u32 and_mask)
+{
+ u32 val;
+
+ val = readl(reg);
+ val |= or_mask;
+ val &= ~and_mask;
+ writel(val, reg);
+}
+
+static int mt6577_auxadc_read(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan)
+{
+ u32 val;
+ void __iomem *reg_channel;
+ int ret;
+ struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
+
+ reg_channel = adc_dev->reg_base + MT6577_AUXADC_DAT0 +
+ chan->channel * 0x04;
+
+ mutex_lock(&adc_dev->lock);
+
+ mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
+ 0, 1 << chan->channel);
+
+ /* read channel and make sure old ready bit == 0 */
+ ret = readl_poll_timeout(reg_channel, val,
+ ((val & MT6577_AUXADC_RDY0) == 0),
+ MT6577_AUXADC_SLEEP_US,
+ MT6577_AUXADC_TIMEOUT_US);
+ if (ret < 0) {
+ dev_err(indio_dev->dev.parent,
+ "wait for channel[%d] ready bit clear time out\n",
+ chan->channel);
+ goto err_timeout;
+ }
+
+ /* set bit to trigger sample */
+ mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_CON1,
+ 1 << chan->channel, 0);
+
+ /* we must delay here for hardware sample channel data */
+ udelay(MT6577_AUXADC_SAMPLE_READY_US);
+
+ /* check MTK_AUXADC_CON2 if auxadc is idle */
+ ret = readl_poll_timeout(adc_dev->reg_base + MT6577_AUXADC_CON2, val,
+ ((val & MT6577_AUXADC_STA) == 0),
+ MT6577_AUXADC_SLEEP_US,
+ MT6577_AUXADC_TIMEOUT_US);
+ if (ret < 0) {
+ dev_err(indio_dev->dev.parent,
+ "wait for auxadc idle time out\n");
+ goto err_timeout;
+ }
+
+ /* read channel and make sure ready bit == 1 */
+ ret = readl_poll_timeout(reg_channel, val,
+ ((val & MT6577_AUXADC_RDY0) != 0),
+ MT6577_AUXADC_SLEEP_US,
+ MT6577_AUXADC_TIMEOUT_US);
+ if (ret < 0) {
+ dev_err(indio_dev->dev.parent,
+ "wait for channel[%d] data ready time out\n",
+ chan->channel);
+ goto err_timeout;
+ }
+
+ /* read data */
+ val = readl(reg_channel) & MT6577_AUXADC_DAT_MASK;
+
+ mutex_unlock(&adc_dev->lock);
+
+ return val;
+
+err_timeout:
+
+ mutex_unlock(&adc_dev->lock);
+
+ return -ETIMEDOUT;
+}
+
+static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val,
+ int *val2,
+ long info)
+{
+ switch (info) {
+ case IIO_CHAN_INFO_PROCESSED:
+ *val = mt6577_auxadc_read(indio_dev, chan);
+ if (*val < 0) {
+ dev_err(indio_dev->dev.parent,
+ "failed to sample data on channel[%d]\n",
+ chan->channel);
+ return *val;
+ }
+ return IIO_VAL_INT;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info mt6577_auxadc_info = {
+ .driver_module = THIS_MODULE,
+ .read_raw = &mt6577_auxadc_read_raw,
+};
+
+static int mt6577_auxadc_probe(struct platform_device *pdev)
+{
+ struct mt6577_auxadc_device *adc_dev;
+ unsigned long adc_clk_rate;
+ struct resource *res;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc_dev = iio_priv(indio_dev);
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->name = dev_name(&pdev->dev);
+ indio_dev->info = &mt6577_auxadc_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = mt6577_auxadc_iio_channels;
+ indio_dev->num_channels = ARRAY_SIZE(mt6577_auxadc_iio_channels);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ adc_dev->reg_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(adc_dev->reg_base)) {
+ dev_err(&pdev->dev, "failed to get auxadc base address\n");
+ return PTR_ERR(adc_dev->reg_base);
+ }
+
+ adc_dev->adc_clk = devm_clk_get(&pdev->dev, "main");
+ if (IS_ERR(adc_dev->adc_clk)) {
+ dev_err(&pdev->dev, "failed to get auxadc clock\n");
+ return PTR_ERR(adc_dev->adc_clk);
+ }
+
+ ret = clk_prepare_enable(adc_dev->adc_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable auxadc clock\n");
+ return ret;
+ }
+
+ adc_clk_rate = clk_get_rate(adc_dev->adc_clk);
+ if (!adc_clk_rate) {
+ ret = -EINVAL;
+ dev_err(&pdev->dev, "null clock rate\n");
+ goto err_disable_clk;
+ }
+
+ mutex_init(&adc_dev->lock);
+
+ mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
+ MT6577_AUXADC_PDN_EN, 0);
+ mdelay(MT6577_AUXADC_POWER_READY_MS);
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ ret = iio_device_register(indio_dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to register iio device\n");
+ goto err_power_off;
+ }
+
+ return 0;
+
+err_power_off:
+ mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
+ 0, MT6577_AUXADC_PDN_EN);
+err_disable_clk:
+ clk_disable_unprepare(adc_dev->adc_clk);
+ return ret;
+}
+
+static int mt6577_auxadc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct mt6577_auxadc_device *adc_dev = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ mt6577_auxadc_mod_reg(adc_dev->reg_base + MT6577_AUXADC_MISC,
+ 0, MT6577_AUXADC_PDN_EN);
+
+ clk_disable_unprepare(adc_dev->adc_clk);
+
+ return 0;
+}
+
+static const struct of_device_id mt6577_auxadc_of_match[] = {
+ { .compatible = "mediatek,mt2701-auxadc", },
+ { .compatible = "mediatek,mt8173-auxadc", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, mt6577_auxadc_of_match);
+
+static struct platform_driver mt6577_auxadc_driver = {
+ .driver = {
+ .name = "mt6577-auxadc",
+ .of_match_table = mt6577_auxadc_of_match,
+ },
+ .probe = mt6577_auxadc_probe,
+ .remove = mt6577_auxadc_remove,
+};
+module_platform_driver(mt6577_auxadc_driver);
+
+MODULE_AUTHOR("Zhiyong Tao <zhiyong.tao@mediatek.com>");
+MODULE_DESCRIPTION("MTK AUXADC Device Driver");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 11:08:42 +0300