mfd: ti_tscadc: Add support for TI's TSC/ADC MFDevice
Add the mfd core driver which supports touchscreen
and ADC.
With this patch we are only adding infrastructure to
support the MFD clients.
Signed-off-by: Patil, Rachna <rachna@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
new file mode 100644
index 0000000..14df67b
--- /dev/null
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -0,0 +1,250 @@
+/*
+ * 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/init.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/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,
+};
+
+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 __devinit ti_tscadc_probe(struct platform_device *pdev)
+{
+ struct ti_tscadc_dev *tscadc;
+ struct resource *res;
+ struct clk *clk;
+ struct mfd_tscadc_board *pdata = pdev->dev.platform_data;
+ int irq;
+ int err, ctrl;
+ int clk_value, clock_rate;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "Could not find platform data\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "no memory resource defined.\n");
+ return -EINVAL;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "no irq ID is specified.\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;
+ tscadc->irq = irq;
+
+ res = devm_request_mem_region(&pdev->dev,
+ res->start, resource_size(res), pdev->name);
+ if (!res) {
+ dev_err(&pdev->dev, "failed to reserve registers.\n");
+ err = -EBUSY;
+ goto err;
+ }
+
+ tscadc->tscadc_base = devm_ioremap(&pdev->dev,
+ res->start, resource_size(res));
+ if (!tscadc->tscadc_base) {
+ dev_err(&pdev->dev, "failed to map registers.\n");
+ err = -ENOMEM;
+ goto err;
+ }
+
+ 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 err;
+ }
+
+ 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);
+ clk_value = clock_rate / ADC_CLK;
+ if (clk_value < MAX_CLK_DIV) {
+ dev_err(&pdev->dev, "clock input less than min clock requirement\n");
+ err = -EINVAL;
+ goto err_disable_clk;
+ }
+ /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
+ clk_value = clk_value - 1;
+ tscadc_writel(tscadc, REG_CLKDIV, clk_value);
+
+ /* Set the control register bits */
+ ctrl = CNTRLREG_STEPCONFIGWRT |
+ CNTRLREG_TSCENB |
+ CNTRLREG_STEPID |
+ CNTRLREG_4WIRE;
+ tscadc_writel(tscadc, REG_CTRL, ctrl);
+
+ /* Set register bits for Idle Config Mode */
+ tscadc_idle_config(tscadc);
+
+ /* Enable the TSC module enable bit */
+ ctrl = tscadc_readl(tscadc, REG_CTRL);
+ ctrl |= CNTRLREG_TSCSSENB;
+ tscadc_writel(tscadc, REG_CTRL, ctrl);
+
+ err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
+ TSCADC_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);
+err:
+ return err;
+}
+
+static int __devexit 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);
+ unsigned int restore, ctrl;
+
+ pm_runtime_get_sync(dev);
+
+ /* context restore */
+ ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
+ CNTRLREG_STEPID | CNTRLREG_4WIRE;
+ tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
+ tscadc_idle_config(tscadc_dev);
+ tscadc_writel(tscadc_dev, REG_SE, STPENB_STEPENB);
+ restore = tscadc_readl(tscadc_dev, REG_CTRL);
+ tscadc_writel(tscadc_dev, REG_CTRL,
+ (restore | CNTRLREG_TSCSSENB));
+
+ 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 struct platform_driver ti_tscadc_driver = {
+ .driver = {
+ .name = "ti_tscadc",
+ .owner = THIS_MODULE,
+ .pm = TSCADC_PM_OPS,
+ },
+ .probe = ti_tscadc_probe,
+ .remove = __devexit_p(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");