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path: root/drivers/mfd/ti_am335x_tscadc.c
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Diffstat (limited to 'drivers/mfd/ti_am335x_tscadc.c')
-rw-r--r--drivers/mfd/ti_am335x_tscadc.c393
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");