mfd: mxs-lradc: Add support for mxs-lradc

Add core files for low resolution analog-to-digital converter (mxs-lradc)
MFD driver.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 267 insertions, 0 deletions

diff --git a/drivers/mfd/mxs-lradc.c b/drivers/mfd/mxs-lradc.c
new file mode 100644
index 000000000000..630bd19b2c0a
--- /dev/null
+++ b/drivers/mfd/mxs-lradc.c
@@ -0,0 +1,267 @@
+/*
+ * Freescale MXS Low Resolution Analog-to-Digital Converter driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
+ *
+ * Authors:
+ *  Marek Vasut <marex@denx.de>
+ *  Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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/device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mxs-lradc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define ADC_CELL		0
+#define TSC_CELL		1
+#define RES_MEM			0
+
+enum mx23_lradc_irqs {
+	MX23_LRADC_TS_IRQ = 0,
+	MX23_LRADC_CH0_IRQ,
+	MX23_LRADC_CH1_IRQ,
+	MX23_LRADC_CH2_IRQ,
+	MX23_LRADC_CH3_IRQ,
+	MX23_LRADC_CH4_IRQ,
+	MX23_LRADC_CH5_IRQ,
+	MX23_LRADC_CH6_IRQ,
+	MX23_LRADC_CH7_IRQ,
+};
+
+enum mx28_lradc_irqs {
+	MX28_LRADC_TS_IRQ = 0,
+	MX28_LRADC_TRESH0_IRQ,
+	MX28_LRADC_TRESH1_IRQ,
+	MX28_LRADC_CH0_IRQ,
+	MX28_LRADC_CH1_IRQ,
+	MX28_LRADC_CH2_IRQ,
+	MX28_LRADC_CH3_IRQ,
+	MX28_LRADC_CH4_IRQ,
+	MX28_LRADC_CH5_IRQ,
+	MX28_LRADC_CH6_IRQ,
+	MX28_LRADC_CH7_IRQ,
+	MX28_LRADC_BUTTON0_IRQ,
+	MX28_LRADC_BUTTON1_IRQ,
+};
+
+static struct resource mx23_adc_resources[] = {
+	DEFINE_RES_MEM(0x0, 0x0),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
+};
+
+static struct resource mx23_touchscreen_resources[] = {
+	DEFINE_RES_MEM(0x0, 0x0),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
+};
+
+static struct resource mx28_adc_resources[] = {
+	DEFINE_RES_MEM(0x0, 0x0),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"),
+};
+
+static struct resource mx28_touchscreen_resources[] = {
+	DEFINE_RES_MEM(0x0, 0x0),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
+};
+
+static struct mfd_cell mx23_cells[] = {
+	{
+		.name = "mxs-lradc-adc",
+		.resources = mx23_adc_resources,
+		.num_resources = ARRAY_SIZE(mx23_adc_resources),
+	},
+	{
+		.name = "mxs-lradc-ts",
+		.resources = mx23_touchscreen_resources,
+		.num_resources = ARRAY_SIZE(mx23_touchscreen_resources),
+	},
+};
+
+static struct mfd_cell mx28_cells[] = {
+	{
+		.name = "mxs-lradc-adc",
+		.resources = mx28_adc_resources,
+		.num_resources = ARRAY_SIZE(mx28_adc_resources),
+	},
+	{
+		.name = "mxs-lradc-ts",
+		.resources = mx28_touchscreen_resources,
+		.num_resources = ARRAY_SIZE(mx28_touchscreen_resources),
+	}
+};
+
+static const struct of_device_id mxs_lradc_dt_ids[] = {
+	{ .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
+	{ .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
+
+static int mxs_lradc_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct mxs_lradc *lradc;
+	struct mfd_cell *cells = NULL;
+	struct resource *res;
+	int ret = 0;
+	u32 ts_wires = 0;
+
+	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
+	if (!lradc)
+		return -ENOMEM;
+
+	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
+	if (!of_id)
+		return -EINVAL;
+
+	lradc->soc = (enum mxs_lradc_id)of_id->data;
+
+	lradc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(lradc->clk)) {
+		dev_err(dev, "Failed to get the delay unit clock\n");
+		return PTR_ERR(lradc->clk);
+	}
+
+	ret = clk_prepare_enable(lradc->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable the delay unit clock\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
+					 &ts_wires);
+
+	if (!ret) {
+		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
+
+		switch (ts_wires) {
+		case 4:
+			lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;
+			break;
+		case 5:
+			if (lradc->soc == IMX28_LRADC) {
+				lradc->touchscreen_wire =
+					MXS_LRADC_TOUCHSCREEN_5WIRE;
+				break;
+			}
+			/* fall through to an error message for i.MX23 */
+		default:
+			dev_err(&pdev->dev,
+				"Unsupported number of touchscreen wires (%d)\n"
+				, ts_wires);
+			ret = -EINVAL;
+			goto err_clk;
+		}
+	} else {
+		lradc->buffer_vchans = BUFFER_VCHANS_ALL;
+	}
+
+	platform_set_drvdata(pdev, lradc);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOMEM;
+
+	switch (lradc->soc) {
+	case IMX23_LRADC:
+		mx23_adc_resources[RES_MEM] = *res;
+		mx23_touchscreen_resources[RES_MEM] = *res;
+		cells = mx23_cells;
+		break;
+	case IMX28_LRADC:
+		mx28_adc_resources[RES_MEM] = *res;
+		mx28_touchscreen_resources[RES_MEM] = *res;
+		cells = mx28_cells;
+		break;
+	default:
+		dev_err(dev, "Unsupported SoC\n");
+		ret = -ENODEV;
+		goto err_clk;
+	}
+
+	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
+				   &cells[ADC_CELL], 1, NULL, 0, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
+		goto err_clk;
+	}
+
+	if (!lradc->touchscreen_wire)
+		return 0;
+
+	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
+				   &cells[TSC_CELL], 1, NULL, 0, NULL);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to add the touchscreen subdevice\n");
+		goto err_clk;
+	}
+
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(lradc->clk);
+
+	return ret;
+}
+
+static int mxs_lradc_remove(struct platform_device *pdev)
+{
+	struct mxs_lradc *lradc = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(lradc->clk);
+
+	return 0;
+}
+
+static struct platform_driver mxs_lradc_driver = {
+	.driver = {
+		.name = "mxs-lradc",
+		.of_match_table = mxs_lradc_dt_ids,
+	},
+	.probe = mxs_lradc_probe,
+	.remove = mxs_lradc_remove,
+};
+module_platform_driver(mxs_lradc_driver);
+
+MODULE_AUTHOR("Ksenija Stanojevic <ksenija.stanojevic@gmail.com>");
+MODULE_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-lradc");