| // 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/platform_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, ®); |
| 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, ®); |
| 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; |
| 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", 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; |
| |
| tscadc->tscadc_base = devm_platform_get_and_ioremap_resource(pdev, 0, &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 void 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); |
| } |
| |
| 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_new = 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"); |