Initial import

1 files changed, 380 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..e4e4b22ee
--- /dev/null
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -0,0 +1,380 @@
+/*
+ * TI Touch Screen / ADC MFD driver
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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 version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#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 unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
+{
+	unsigned int val;
+
+	regmap_read(tsadc->regmap_tscadc, reg, &val);
+	return val;
+}
+
+static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
+					unsigned int val)
+{
+	regmap_write(tsadc->regmap_tscadc, reg, val);
+}
+
+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 *tsadc, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tsadc->reg_lock, flags);
+	tsadc->reg_se_cache |= val;
+	if (tsadc->adc_waiting)
+		wake_up(&tsadc->reg_se_wait);
+	else if (!tsadc->adc_in_use)
+		tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
+
+	spin_unlock_irqrestore(&tsadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache);
+
+static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tsadc)
+{
+	DEFINE_WAIT(wait);
+	u32 reg;
+
+	reg = tscadc_readl(tsadc, REG_ADCFSM);
+	if (reg & SEQ_STATUS) {
+		tsadc->adc_waiting = true;
+		prepare_to_wait(&tsadc->reg_se_wait, &wait,
+				TASK_UNINTERRUPTIBLE);
+		spin_unlock_irq(&tsadc->reg_lock);
+
+		schedule();
+
+		spin_lock_irq(&tsadc->reg_lock);
+		finish_wait(&tsadc->reg_se_wait, &wait);
+
+		/*
+		 * Sequencer should either be idle or
+		 * busy applying the charge step.
+		 */
+		reg = tscadc_readl(tsadc, REG_ADCFSM);
+		WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP));
+		tsadc->adc_waiting = false;
+	}
+	tsadc->adc_in_use = true;
+}
+
+void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val)
+{
+	spin_lock_irq(&tsadc->reg_lock);
+	am335x_tscadc_need_adc(tsadc);
+
+	tscadc_writel(tsadc, REG_SE, val);
+	spin_unlock_irq(&tsadc->reg_lock);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once);
+
+void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tsadc)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tsadc->reg_lock, flags);
+	tsadc->adc_in_use = false;
+	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
+	spin_unlock_irqrestore(&tsadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done);
+
+void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tsadc->reg_lock, flags);
+	tsadc->reg_se_cache &= ~val;
+	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
+	spin_unlock_irqrestore(&tsadc->reg_lock, flags);
+}
+EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
+
+static void tscadc_idle_config(struct ti_tscadc_dev *config)
+{
+	unsigned int idleconfig;
+
+	idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
+			STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
+
+	tscadc_writel(config, 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 = pdev->dev.of_node;
+	struct mfd_cell		*cell;
+	struct property         *prop;
+	const __be32            *cur;
+	u32			val;
+	int			err, ctrl;
+	int			clock_rate;
+	int			tsc_wires = 0, adc_channels = 0, total_channels;
+	int			readouts = 0;
+
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "Could not find valid DT data.\n");
+		return -EINVAL;
+	}
+
+	node = of_get_child_by_name(pdev->dev.of_node, "tsc");
+	of_property_read_u32(node, "ti,wires", &tsc_wires);
+	of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
+
+	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);
+			return -EINVAL;
+		}
+	}
+	total_channels = tsc_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 atleast one channel.\n");
+		return -EINVAL;
+	}
+
+	if (readouts * 2 + 2 + adc_channels > 16) {
+		dev_err(&pdev->dev, "Too many step configurations requested\n");
+		return -EINVAL;
+	}
+
+	/* Allocate memory for device */
+	tscadc = devm_kzalloc(&pdev->dev,
+			sizeof(struct ti_tscadc_dev), GFP_KERNEL);
+	if (!tscadc) {
+		dev_err(&pdev->dev, "failed to allocate memory.\n");
+		return -ENOMEM;
+	}
+	tscadc->dev = &pdev->dev;
+
+	err = platform_get_irq(pdev, 0);
+	if (err < 0) {
+		dev_err(&pdev->dev, "no irq ID is specified.\n");
+		goto ret;
+	} 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->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
+			tscadc->tscadc_base, &tscadc_regmap_config);
+	if (IS_ERR(tscadc->regmap_tscadc)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		err = PTR_ERR(tscadc->regmap_tscadc);
+		goto ret;
+	}
+
+	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.
+	 * The ADC clock is expected to run at target of 3MHz,
+	 * and expected to capture 12-bit data at a rate of 200 KSPS.
+	 * The TSC_ADC_SS controller design assumes the OCP clock is
+	 * at least 6x faster than the ADC clock.
+	 */
+	clk = clk_get(&pdev->dev, "adc_tsc_fck");
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed to get TSC fck\n");
+		err = PTR_ERR(clk);
+		goto err_disable_clk;
+	}
+	clock_rate = clk_get_rate(clk);
+	clk_put(clk);
+	tscadc->clk_div = clock_rate / ADC_CLK;
+
+	/* TSCADC_CLKDIV needs to be configured to the value minus 1 */
+	tscadc->clk_div--;
+	tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);
+
+	/* Set the control register bits */
+	ctrl = CNTRLREG_STEPCONFIGWRT |	CNTRLREG_STEPID;
+	tscadc_writel(tscadc, REG_CTRL, ctrl);
+
+	/* Set register bits for Idle Config Mode */
+	if (tsc_wires > 0) {
+		tscadc->tsc_wires = tsc_wires;
+		if (tsc_wires == 5)
+			ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
+		else
+			ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
+		tscadc_idle_config(tscadc);
+	}
+
+	/* Enable the TSC module enable bit */
+	ctrl |= CNTRLREG_TSCSSENB;
+	tscadc_writel(tscadc, REG_CTRL, ctrl);
+
+	tscadc->used_cells = 0;
+	tscadc->tsc_cell = -1;
+	tscadc->adc_cell = -1;
+
+	/* TSC Cell */
+	if (tsc_wires > 0) {
+		tscadc->tsc_cell = tscadc->used_cells;
+		cell = &tscadc->cells[tscadc->used_cells++];
+		cell->name = "TI-am335x-tsc";
+		cell->of_compatible = "ti,am3359-tsc";
+		cell->platform_data = &tscadc;
+		cell->pdata_size = sizeof(tscadc);
+	}
+
+	/* ADC Cell */
+	if (adc_channels > 0) {
+		tscadc->adc_cell = tscadc->used_cells;
+		cell = &tscadc->cells[tscadc->used_cells++];
+		cell->name = "TI-am335x-adc";
+		cell->of_compatible = "ti,am3359-adc";
+		cell->platform_data = &tscadc;
+		cell->pdata_size = sizeof(tscadc);
+	}
+
+	err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
+			tscadc->used_cells, NULL, 0, NULL);
+	if (err < 0)
+		goto err_disable_clk;
+
+	device_init_wakeup(&pdev->dev, true);
+	platform_set_drvdata(pdev, tscadc);
+	return 0;
+
+err_disable_clk:
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+ret:
+	return err;
+}
+
+static int ti_tscadc_remove(struct platform_device *pdev)
+{
+	struct ti_tscadc_dev	*tscadc = platform_get_drvdata(pdev);
+
+	tscadc_writel(tscadc, REG_SE, 0x00);
+
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	mfd_remove_devices(tscadc->dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int tscadc_suspend(struct device *dev)
+{
+	struct ti_tscadc_dev	*tscadc_dev = dev_get_drvdata(dev);
+
+	tscadc_writel(tscadc_dev, REG_SE, 0x00);
+	pm_runtime_put_sync(dev);
+
+	return 0;
+}
+
+static int tscadc_resume(struct device *dev)
+{
+	struct ti_tscadc_dev	*tscadc_dev = dev_get_drvdata(dev);
+	u32 ctrl;
+
+	pm_runtime_get_sync(dev);
+
+	/* context restore */
+	ctrl = CNTRLREG_STEPCONFIGWRT |	CNTRLREG_STEPID;
+	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
+
+	if (tscadc_dev->tsc_cell != -1) {
+		if (tscadc_dev->tsc_wires == 5)
+			ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB;
+		else
+			ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
+		tscadc_idle_config(tscadc_dev);
+	}
+	ctrl |= CNTRLREG_TSCSSENB;
+	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
+
+	tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
+
+	return 0;
+}
+
+static const struct dev_pm_ops tscadc_pm_ops = {
+	.suspend = tscadc_suspend,
+	.resume = tscadc_resume,
+};
+#define TSCADC_PM_OPS (&tscadc_pm_ops)
+#else
+#define TSCADC_PM_OPS NULL
+#endif
+
+static const struct of_device_id ti_tscadc_dt_ids[] = {
+	{ .compatible = "ti,am3359-tscadc", },
+	{ }
+};
+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 / ADC MFD controller driver");
+MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
+MODULE_LICENSE("GPL");