1 files changed, 393 insertions, 0 deletions

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
new file mode 100644
index 000000000..07825cfd8
--- /dev/null
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -0,0 +1,393 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * TI Touch Screen / ADC MFD driver
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/mfd/core.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/sched.h>
+
+#include <linux/mfd/ti_am335x_tscadc.h>
+
+static const struct regmap_config tscadc_regmap_config = {
+	.name = "ti_tscadc",
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+};
+
+void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tscadc, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tscadc->reg_lock, flags);
+	tscadc->reg_se_cache |= val;
+	if (tscadc->adc_waiting)
+		wake_up(&tscadc->reg_se_wait);
+	else if (!tscadc->adc_in_use)
+		regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
+
+	spin_unlock_irqrestore(&tscadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
+
+static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tscadc)
+{
+	DEFINE_WAIT(wait);
+	u32 reg;
+
+	regmap_read(tscadc->regmap, REG_ADCFSM, &reg);
+	if (reg & SEQ_STATUS) {
+		tscadc->adc_waiting = true;
+		prepare_to_wait(&tscadc->reg_se_wait, &wait,
+				TASK_UNINTERRUPTIBLE);
+		spin_unlock_irq(&tscadc->reg_lock);
+
+		schedule();
+
+		spin_lock_irq(&tscadc->reg_lock);
+		finish_wait(&tscadc->reg_se_wait, &wait);
+
+		/*
+		 * Sequencer should either be idle or
+		 * busy applying the charge step.
+		 */
+		regmap_read(tscadc->regmap, REG_ADCFSM, &reg);
+		WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
+		tscadc->adc_waiting = false;
+	}
+	tscadc->adc_in_use = true;
+}
+
+void am335x_tsc_se_set_once(struct ti_tscadc_dev *tscadc, u32 val)
+{
+	spin_lock_irq(&tscadc->reg_lock);
+	am335x_tscadc_need_adc(tscadc);
+
+	regmap_write(tscadc->regmap, REG_SE, val);
+	spin_unlock_irq(&tscadc->reg_lock);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
+
+void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tscadc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tscadc->reg_lock, flags);
+	tscadc->adc_in_use = false;
+	regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
+	spin_unlock_irqrestore(&tscadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
+
+void am335x_tsc_se_clr(struct ti_tscadc_dev *tscadc, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tscadc->reg_lock, flags);
+	tscadc->reg_se_cache &= ~val;
+	regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache);
+	spin_unlock_irqrestore(&tscadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
+
+static void tscadc_idle_config(struct ti_tscadc_dev *tscadc)
+{
+	unsigned int idleconfig;
+
+	idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM;
+	if (ti_adc_with_touchscreen(tscadc))
+		idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN;
+
+	regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig);
+}
+
+static	int ti_tscadc_probe(struct platform_device *pdev)
+{
+	struct ti_tscadc_dev *tscadc;
+	struct resource *res;
+	struct clk *clk;
+	struct device_node *node;
+	struct mfd_cell *cell;
+	struct property *prop;
+	const __be32 *cur;
+	bool use_tsc = false, use_mag = false;
+	u32 val;
+	int err;
+	int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels;
+	int readouts = 0, mag_tracks = 0;
+
+	/* Allocate memory for device */
+	tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL);
+	if (!tscadc)
+		return -ENOMEM;
+
+	tscadc->dev = &pdev->dev;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "Could not find valid DT data.\n");
+		return -EINVAL;
+	}
+
+	tscadc->data = of_device_get_match_data(&pdev->dev);
+
+	if (ti_adc_with_touchscreen(tscadc)) {
+		node = of_get_child_by_name(pdev->dev.of_node, "tsc");
+		of_property_read_u32(node, "ti,wires", &tscmag_wires);
+		err = of_property_read_u32(node, "ti,coordinate-readouts",
+					   &readouts);
+		if (err < 0)
+			of_property_read_u32(node, "ti,coordiante-readouts",
+					     &readouts);
+
+		of_node_put(node);
+
+		if (tscmag_wires)
+			use_tsc = true;
+	} else {
+		/*
+		 * When adding support for the magnetic stripe reader, here is
+		 * the place to look for the number of tracks used from device
+		 * tree. Let's default to 0 for now.
+		 */
+		mag_tracks = 0;
+		tscmag_wires = mag_tracks * 2;
+		if (tscmag_wires)
+			use_mag = true;
+	}
+
+	node = of_get_child_by_name(pdev->dev.of_node, "adc");
+	of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
+		adc_channels++;
+		if (val > 7) {
+			dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
+				val);
+			of_node_put(node);
+			return -EINVAL;
+		}
+	}
+
+	of_node_put(node);
+
+	total_channels = tscmag_wires + adc_channels;
+	if (total_channels > 8) {
+		dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
+		return -EINVAL;
+	}
+
+	if (total_channels == 0) {
+		dev_err(&pdev->dev, "Need at least one channel.\n");
+		return -EINVAL;
+	}
+
+	if (use_tsc && (readouts * 2 + 2 + adc_channels > 16)) {
+		dev_err(&pdev->dev, "Too many step configurations requested\n");
+		return -EINVAL;
+	}
+
+	err = platform_get_irq(pdev, 0);
+	if (err < 0)
+		return err;
+	else
+		tscadc->irq = err;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tscadc->tscadc_base))
+		return PTR_ERR(tscadc->tscadc_base);
+
+	tscadc->tscadc_phys_base = res->start;
+	tscadc->regmap = devm_regmap_init_mmio(&pdev->dev,
+					       tscadc->tscadc_base,
+					       &tscadc_regmap_config);
+	if (IS_ERR(tscadc->regmap)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		return PTR_ERR(tscadc->regmap);
+	}
+
+	spin_lock_init(&tscadc->reg_lock);
+	init_waitqueue_head(&tscadc->reg_se_wait);
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	/*
+	 * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK.
+	 * ADCs produce a 12-bit sample every 15 ADC_CLK cycles.
+	 * am33xx ADCs expect to capture 200ksps.
+	 * am47xx ADCs expect to capture 867ksps.
+	 * We need ADC clocks respectively running at 3MHz and 13MHz.
+	 * These frequencies are valid since TSC_ADC_SS controller design
+	 * assumes the OCP clock is at least 6x faster than the ADC clock.
+	 */
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed to get fck\n");
+		err = PTR_ERR(clk);
+		goto err_disable_clk;
+	}
+
+	tscadc->clk_div = (clk_get_rate(clk) / tscadc->data->target_clk_rate) - 1;
+	regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
+
+	/*
+	 * Set the control register bits. tscadc->ctrl stores the configuration
+	 * of the CTRL register but not the subsystem enable bit which must be
+	 * added manually when timely.
+	 */
+	tscadc->ctrl = CNTRLREG_STEPID;
+	if (ti_adc_with_touchscreen(tscadc)) {
+		tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT;
+		if (use_tsc) {
+			tscadc->ctrl |= CNTRLREG_TSC_ENB;
+			if (tscmag_wires == 5)
+				tscadc->ctrl |= CNTRLREG_TSC_5WIRE;
+			else
+				tscadc->ctrl |= CNTRLREG_TSC_4WIRE;
+		}
+	} else {
+		tscadc->ctrl |= CNTRLREG_MAG_PREAMP_PWRDOWN |
+				CNTRLREG_MAG_PREAMP_BYPASS;
+	}
+	regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
+
+	tscadc_idle_config(tscadc);
+
+	/* Enable the TSC module enable bit */
+	regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
+
+	/* TSC or MAG Cell */
+	if (use_tsc || use_mag) {
+		cell = &tscadc->cells[cell_idx++];
+		cell->name = tscadc->data->secondary_feature_name;
+		cell->of_compatible = tscadc->data->secondary_feature_compatible;
+		cell->platform_data = &tscadc;
+		cell->pdata_size = sizeof(tscadc);
+	}
+
+	/* ADC Cell */
+	if (adc_channels > 0) {
+		cell = &tscadc->cells[cell_idx++];
+		cell->name = tscadc->data->adc_feature_name;
+		cell->of_compatible = tscadc->data->adc_feature_compatible;
+		cell->platform_data = &tscadc;
+		cell->pdata_size = sizeof(tscadc);
+	}
+
+	err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
+			      tscadc->cells, cell_idx, NULL, 0, NULL);
+	if (err < 0)
+		goto err_disable_clk;
+
+	platform_set_drvdata(pdev, tscadc);
+	return 0;
+
+err_disable_clk:
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return err;
+}
+
+static int ti_tscadc_remove(struct platform_device *pdev)
+{
+	struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
+
+	regmap_write(tscadc->regmap, REG_SE, 0x00);
+
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	mfd_remove_devices(tscadc->dev);
+
+	return 0;
+}
+
+static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data)
+{
+	return device_may_wakeup(dev);
+}
+
+static int __maybe_unused tscadc_suspend(struct device *dev)
+{
+	struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);
+
+	regmap_write(tscadc->regmap, REG_SE, 0x00);
+	if (device_for_each_child(dev, NULL, ti_tscadc_can_wakeup)) {
+		u32 ctrl;
+
+		regmap_read(tscadc->regmap, REG_CTRL, &ctrl);
+		ctrl &= ~(CNTRLREG_POWERDOWN);
+		ctrl |= CNTRLREG_SSENB;
+		regmap_write(tscadc->regmap, REG_CTRL, ctrl);
+	}
+	pm_runtime_put_sync(dev);
+
+	return 0;
+}
+
+static int __maybe_unused tscadc_resume(struct device *dev)
+{
+	struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev);
+
+	pm_runtime_get_sync(dev);
+
+	regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div);
+	regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl);
+	tscadc_idle_config(tscadc);
+	regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume);
+
+static const struct ti_tscadc_data tscdata = {
+	.adc_feature_name = "TI-am335x-adc",
+	.adc_feature_compatible = "ti,am3359-adc",
+	.secondary_feature_name = "TI-am335x-tsc",
+	.secondary_feature_compatible = "ti,am3359-tsc",
+	.target_clk_rate = TSC_ADC_CLK,
+};
+
+static const struct ti_tscadc_data magdata = {
+	.adc_feature_name = "TI-am43xx-adc",
+	.adc_feature_compatible = "ti,am4372-adc",
+	.secondary_feature_name = "TI-am43xx-mag",
+	.secondary_feature_compatible = "ti,am4372-mag",
+	.target_clk_rate = MAG_ADC_CLK,
+};
+
+static const struct of_device_id ti_tscadc_dt_ids[] = {
+	{ .compatible = "ti,am3359-tscadc", .data = &tscdata },
+	{ .compatible = "ti,am4372-magadc", .data = &magdata },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
+
+static struct platform_driver ti_tscadc_driver = {
+	.driver = {
+		.name   = "ti_am3359-tscadc",
+		.pm	= &tscadc_pm_ops,
+		.of_match_table = ti_tscadc_dt_ids,
+	},
+	.probe	= ti_tscadc_probe,
+	.remove	= ti_tscadc_remove,
+
+};
+
+module_platform_driver(ti_tscadc_driver);
+
+MODULE_DESCRIPTION("TI touchscreen/magnetic stripe reader/ADC MFD controller driver");
+MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
+MODULE_LICENSE("GPL");