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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/mfd/ti_am335x_tscadc.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/mfd/ti_am335x_tscadc.c')
-rw-r--r-- | drivers/mfd/ti_am335x_tscadc.c | 393 |
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, ®); + 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; + 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"); |