diff options
Diffstat (limited to 'drivers/mfd/ti_am335x_tscadc.c')
| -rw-r--r-- | drivers/mfd/ti_am335x_tscadc.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c new file mode 100644 index 00000000000..8ca3bf023fb --- /dev/null +++ b/drivers/mfd/ti_am335x_tscadc.c @@ -0,0 +1,274 @@ +/* + * 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> +#include <linux/input/ti_am335x_tsc.h> +#include <linux/platform_data/ti_am335x_adc.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; + struct mfd_cell *cell; + int err, ctrl; + int clk_value, clock_rate; + int tsc_wires, adc_channels = 0, total_channels; + + if (!pdata) { + dev_err(&pdev->dev, "Could not find platform data\n"); + return -EINVAL; + } + + if (pdata->adc_init) + adc_channels = pdata->adc_init->adc_channels; + + tsc_wires = pdata->tsc_init->wires; + 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; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "no memory resource defined.\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; + + 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 = devm_request_mem_region(&pdev->dev, + res->start, resource_size(res), pdev->name); + if (!res) { + dev_err(&pdev->dev, "failed to reserve registers.\n"); + return -EBUSY; + } + + 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"); + return -ENOMEM; + } + + 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 ret; + } + + 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); + + /* TSC Cell */ + cell = &tscadc->cells[TSC_CELL]; + cell->name = "tsc"; + cell->platform_data = tscadc; + cell->pdata_size = sizeof(*tscadc); + + /* ADC Cell */ + cell = &tscadc->cells[ADC_CELL]; + cell->name = "tiadc"; + cell->platform_data = tscadc; + cell->pdata_size = sizeof(*tscadc); + + 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); +ret: + 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"); |