Re: [PATCH v2 1/4] mfd: mxs-lradc: Add support for mxs-lradc MFD

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
---
Changes in v2:
 - do not change spacing in Kconfig
 - make struct mfd_cell part of struct mxs_lradc
 - use switch instead of if in mxs_lradc_irq_mask
 - use only necessary header files in mxs_lradc.h
 - use devm_mfd_add_device
 - use separate function to register mfd device
 - change licence to GPL
 - add copyright

 drivers/mfd/Kconfig           |  17 ++++
 drivers/mfd/Makefile          |   1 +
 drivers/mfd/mxs-lradc.c       | 215
++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/mxs-lradc.h | 204 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 437 insertions(+)
 create mode 100644 drivers/mfd/mxs-lradc.c
 create mode 100644 include/linux/mfd/mxs-lradc.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 9ca66de..62593ad 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig

@@ -271,6 +271,23 @@ config MFD_MC13XXX_I2C
 	help
 	  Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_MXS_LRADC
+	tristate "Freescale i.MX23/i.MX28 LRADC"
+	depends on ARCH_MXS || COMPILE_TEST
+	select MFD_CORE
+	select STMP_DEVICE
+	help
+	  Say yes here to build support for the low-resolution
+	  analog-to-digital converter (LRADC) found on the i.MX23 and i.MX28
+	  processors. This driver provides common support for accessing the
+	  device, additional drivers must be enabled in order to use the
+	  functionality of the device:
+		mxs-lradc-adc for ADC readings
+		mxs-lradc-ts  for touchscreen support
+
+	  This driver can also be built as a module. If so, the module will be
+	  called mxs-lradc.
+
 config MFD_HI6421_PMIC
 	tristate "HiSilicon Hi6421 PMU/Codec IC"
 	depends on OF

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 0f230a6..ecf6399 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile

@@ -198,3 +198,4 @@ intel-soc-pmic-objs		:= intel_soc_pmic_core.o

intel_soc_pmic_crc.o
 intel-soc-pmic-$(CONFIG_INTEL_PMC_IPC)	+= intel_soc_pmic_bxtwc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
 obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
+obj-$(CONFIG_MFD_MXS_LRADC)	+= mxs-lradc.o

diff --git a/drivers/mfd/mxs-lradc.c b/drivers/mfd/mxs-lradc.c
new file mode 100644
index 0000000..5e894bb
--- /dev/null
+++ b/drivers/mfd/mxs-lradc.c

@@ -0,0 +1,215 @@
+/*
+ * Freescale MXS LRADC driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ * 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>
+
+static const char * const mx23_lradc_irq_names[] = {
+	"mxs-lradc-touchscreen",
+	"mxs-lradc-channel0",
+	"mxs-lradc-channel1",
+	"mxs-lradc-channel2",
+	"mxs-lradc-channel3",
+	"mxs-lradc-channel4",
+	"mxs-lradc-channel5",
+	"mxs-lradc-channel6",
+	"mxs-lradc-channel7",
+};
+
+static const char * const mx28_lradc_irq_names[] = {
+	"mxs-lradc-touchscreen",
+	"mxs-lradc-thresh0",
+	"mxs-lradc-thresh1",
+	"mxs-lradc-channel0",
+	"mxs-lradc-channel1",
+	"mxs-lradc-channel2",
+	"mxs-lradc-channel3",
+	"mxs-lradc-channel4",
+	"mxs-lradc-channel5",
+	"mxs-lradc-channel6",
+	"mxs-lradc-channel7",
+	"mxs-lradc-button0",
+	"mxs-lradc-button1",
+};
+
+struct mxs_lradc_of_config {
+	const int		irq_count;
+	const char * const	*irq_name;
+};
+
+static const struct mxs_lradc_of_config mxs_lradc_of_config[] = {
+	[IMX23_LRADC] = {
+		.irq_count	= ARRAY_SIZE(mx23_lradc_irq_names),
+		.irq_name	= mx23_lradc_irq_names,
+	},
+	[IMX28_LRADC] = {
+		.irq_count	= ARRAY_SIZE(mx28_lradc_irq_names),
+		.irq_name	= mx28_lradc_irq_names,
+	},
+};
+
+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_add_device(struct platform_device *pdev,
+				struct mxs_lradc *lradc, char *name, int i)
+{
+	struct mfd_cell *cell;
+
+	cell = &lradc->cells[i];
+	cell->name = name;
+	cell->platform_data = lradc;
+	cell->pdata_size = sizeof(*lradc);
+
+	return devm_mfd_add_devices(&pdev->dev, -1, cell, 1, NULL, 0, NULL);
+}
+
+static int mxs_lradc_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id =
+		of_match_device(mxs_lradc_dt_ids, &pdev->dev);
+	const struct mxs_lradc_of_config *of_cfg =
+		&mxs_lradc_of_config[(enum mxs_lradc_id)of_id->data];
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct mxs_lradc *lradc;
+	struct resource *iores;
+	int ret = 0, touch_ret, i;
+	u32 ts_wires = 0;
+
+	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
+	if (!lradc)
+		return -ENOMEM;
+	lradc->soc = (enum mxs_lradc_id)of_id->data;
+
+	/* Grab the memory area */
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	lradc->base = devm_ioremap_resource(dev, iores);
+	if (IS_ERR(lradc->base))
+		return PTR_ERR(lradc->base);
+
+	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 != 0) {
+		dev_err(dev, "Failed to enable the delay unit clock\n");
+		return ret;
+	}
+
+	touch_ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
+					 &ts_wires);
+
+	if (touch_ret == 0)
+		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
+	else
+		lradc->buffer_vchans = BUFFER_VCHANS_ALL;
+
+	lradc->irq_count = of_cfg->irq_count;
+	lradc->irq_name = of_cfg->irq_name;
+	for (i = 0; i < lradc->irq_count; i++) {
+		lradc->irq[i] = platform_get_irq(pdev, i);
+		if (lradc->irq[i] < 0) {
+			ret = lradc->irq[i];
+			goto err_clk;
+		}
+	}
+
+	platform_set_drvdata(pdev, lradc);
+
+	ret = stmp_reset_block(lradc->base);
+	if (ret)
+		return ret;
+
+	switch (ts_wires) {
+	case 4:
+		lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
+		break;
+	case 5:
+		if (lradc->soc == IMX28_LRADC) {
+			lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
+			break;
+		}
+		/* fall through an error message for i.MX23 */
+	default:
+		dev_err(&pdev->dev,
+			"Unsupported number of touchscreen wires (%d)\n",
+			ts_wires);
+		return -EINVAL;
+	}

+
+	ret = mxs_lradc_add_device(pdev, lradc, DRIVER_NAME_ADC, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
+		goto err_clk;
+	}
+
+	if (!lradc->use_touchscreen)
+		return 0;
+
+	ret = mxs_lradc_add_device(pdev, lradc, DRIVER_NAME_TS, 1);
+	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_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");
+MODULE_LICENSE("GPL");