diff options
Diffstat (limited to 'drivers/mfd/ti_am335x_tscadc.c')
| -rw-r--r-- | drivers/mfd/ti_am335x_tscadc.c | 369 |
1 files changed, 369 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..0e6e25308 --- /dev/null +++ b/drivers/mfd/ti_am335x_tscadc.c @@ -0,0 +1,369 @@ +/* + * TI Touch Screen / ADC MFD driver + * + * Copyright (C) 2012 Texas Instruments Incorporated - https://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 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_YNN | STEPCONFIG_INM_ADCREFM | + STEPCONFIG_INP_ADCREFM | 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; + 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(*tscadc), GFP_KERNEL); + if (!tscadc) + 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->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"); + err = PTR_ERR(tscadc->regmap); + 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 = devm_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); + tscadc->clk_div = clock_rate / ADC_CLK; + + /* TSCADC_CLKDIV needs to be configured to the value minus 1 */ + tscadc->clk_div--; + regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); + + /* Set the control register bits */ + ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID; + regmap_write(tscadc->regmap, 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; + regmap_write(tscadc->regmap, 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, PLATFORM_DEVID_AUTO, + tscadc->cells, tscadc->used_cells, 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); +ret: + 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_TSCSSENB; + 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); + u32 ctrl; + + pm_runtime_get_sync(dev); + + /* context restore */ + ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID; + regmap_write(tscadc->regmap, REG_CTRL, ctrl); + + if (tscadc->tsc_cell != -1) { + if (tscadc->tsc_wires == 5) + ctrl |= CNTRLREG_5WIRE | CNTRLREG_TSCENB; + else + ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB; + tscadc_idle_config(tscadc); + } + ctrl |= CNTRLREG_TSCSSENB; + regmap_write(tscadc->regmap, REG_CTRL, ctrl); + + regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume); + +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"); |