2 * TI Touch Screen / ADC MFD driver
4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation version 2.
10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11 * kind, whether express or implied; without even the implied warranty
12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/err.h>
21 #include <linux/clk.h>
22 #include <linux/regmap.h>
23 #include <linux/mfd/core.h>
24 #include <linux/pm_runtime.h>
26 #include <linux/of_device.h>
28 #include <linux/mfd/ti_am335x_tscadc.h>
30 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
34 regmap_read(tsadc->regmap_tscadc, reg, &val);
38 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
41 regmap_write(tsadc->regmap_tscadc, reg, val);
44 static const struct regmap_config tscadc_regmap_config = {
51 void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc)
53 tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
55 EXPORT_SYMBOL_GPL(am335x_tsc_se_update);
57 void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val)
61 spin_lock_irqsave(&tsadc->reg_lock, flags);
62 tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE);
63 tsadc->reg_se_cache |= val;
64 am335x_tsc_se_update(tsadc);
65 spin_unlock_irqrestore(&tsadc->reg_lock, flags);
67 EXPORT_SYMBOL_GPL(am335x_tsc_se_set);
69 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
73 spin_lock_irqsave(&tsadc->reg_lock, flags);
74 tsadc->reg_se_cache = tscadc_readl(tsadc, REG_SE);
75 tsadc->reg_se_cache &= ~val;
76 am335x_tsc_se_update(tsadc);
77 spin_unlock_irqrestore(&tsadc->reg_lock, flags);
79 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);
81 static void tscadc_idle_config(struct ti_tscadc_dev *config)
83 unsigned int idleconfig;
85 idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
86 STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;
88 tscadc_writel(config, REG_IDLECONFIG, idleconfig);
91 static int ti_tscadc_probe(struct platform_device *pdev)
93 struct ti_tscadc_dev *tscadc;
96 struct device_node *node = pdev->dev.of_node;
97 struct mfd_cell *cell;
98 struct property *prop;
103 int tsc_wires = 0, adc_channels = 0, total_channels;
106 if (!pdev->dev.of_node) {
107 dev_err(&pdev->dev, "Could not find valid DT data.\n");
111 node = of_get_child_by_name(pdev->dev.of_node, "tsc");
112 of_property_read_u32(node, "ti,wires", &tsc_wires);
113 of_property_read_u32(node, "ti,coordiante-readouts", &readouts);
115 node = of_get_child_by_name(pdev->dev.of_node, "adc");
116 of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
119 dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
124 total_channels = tsc_wires + adc_channels;
125 if (total_channels > 8) {
126 dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
129 if (total_channels == 0) {
130 dev_err(&pdev->dev, "Need atleast one channel.\n");
134 if (readouts * 2 + 2 + adc_channels > 16) {
135 dev_err(&pdev->dev, "Too many step configurations requested\n");
139 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
141 dev_err(&pdev->dev, "no memory resource defined.\n");
145 /* Allocate memory for device */
146 tscadc = devm_kzalloc(&pdev->dev,
147 sizeof(struct ti_tscadc_dev), GFP_KERNEL);
149 dev_err(&pdev->dev, "failed to allocate memory.\n");
152 tscadc->dev = &pdev->dev;
154 err = platform_get_irq(pdev, 0);
156 dev_err(&pdev->dev, "no irq ID is specified.\n");
161 res = devm_request_mem_region(&pdev->dev,
162 res->start, resource_size(res), pdev->name);
164 dev_err(&pdev->dev, "failed to reserve registers.\n");
168 tscadc->tscadc_base = devm_ioremap(&pdev->dev,
169 res->start, resource_size(res));
170 if (!tscadc->tscadc_base) {
171 dev_err(&pdev->dev, "failed to map registers.\n");
175 tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
176 tscadc->tscadc_base, &tscadc_regmap_config);
177 if (IS_ERR(tscadc->regmap_tscadc)) {
178 dev_err(&pdev->dev, "regmap init failed\n");
179 err = PTR_ERR(tscadc->regmap_tscadc);
183 spin_lock_init(&tscadc->reg_lock);
184 pm_runtime_enable(&pdev->dev);
185 pm_runtime_get_sync(&pdev->dev);
188 * The TSC_ADC_Subsystem has 2 clock domains
189 * OCP_CLK and ADC_CLK.
190 * The ADC clock is expected to run at target of 3MHz,
191 * and expected to capture 12-bit data at a rate of 200 KSPS.
192 * The TSC_ADC_SS controller design assumes the OCP clock is
193 * at least 6x faster than the ADC clock.
195 clk = clk_get(&pdev->dev, "adc_tsc_fck");
197 dev_err(&pdev->dev, "failed to get TSC fck\n");
199 goto err_disable_clk;
201 clock_rate = clk_get_rate(clk);
203 tscadc->clk_div = clock_rate / ADC_CLK;
205 /* TSCADC_CLKDIV needs to be configured to the value minus 1 */
207 tscadc_writel(tscadc, REG_CLKDIV, tscadc->clk_div);
209 /* Set the control register bits */
210 ctrl = CNTRLREG_STEPCONFIGWRT |
213 ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
214 tscadc_writel(tscadc, REG_CTRL, ctrl);
216 /* Set register bits for Idle Config Mode */
218 tscadc_idle_config(tscadc);
220 /* Enable the TSC module enable bit */
221 ctrl = tscadc_readl(tscadc, REG_CTRL);
222 ctrl |= CNTRLREG_TSCSSENB;
223 tscadc_writel(tscadc, REG_CTRL, ctrl);
225 tscadc->used_cells = 0;
226 tscadc->tsc_cell = -1;
227 tscadc->adc_cell = -1;
231 tscadc->tsc_cell = tscadc->used_cells;
232 cell = &tscadc->cells[tscadc->used_cells++];
233 cell->name = "TI-am335x-tsc";
234 cell->of_compatible = "ti,am3359-tsc";
235 cell->platform_data = &tscadc;
236 cell->pdata_size = sizeof(tscadc);
240 if (adc_channels > 0) {
241 tscadc->adc_cell = tscadc->used_cells;
242 cell = &tscadc->cells[tscadc->used_cells++];
243 cell->name = "TI-am335x-adc";
244 cell->of_compatible = "ti,am3359-adc";
245 cell->platform_data = &tscadc;
246 cell->pdata_size = sizeof(tscadc);
249 err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
250 tscadc->used_cells, NULL, 0, NULL);
252 goto err_disable_clk;
254 device_init_wakeup(&pdev->dev, true);
255 platform_set_drvdata(pdev, tscadc);
259 pm_runtime_put_sync(&pdev->dev);
260 pm_runtime_disable(&pdev->dev);
265 static int ti_tscadc_remove(struct platform_device *pdev)
267 struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);
269 tscadc_writel(tscadc, REG_SE, 0x00);
271 pm_runtime_put_sync(&pdev->dev);
272 pm_runtime_disable(&pdev->dev);
274 mfd_remove_devices(tscadc->dev);
280 static int tscadc_suspend(struct device *dev)
282 struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
284 tscadc_writel(tscadc_dev, REG_SE, 0x00);
285 pm_runtime_put_sync(dev);
290 static int tscadc_resume(struct device *dev)
292 struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
293 unsigned int restore, ctrl;
295 pm_runtime_get_sync(dev);
297 /* context restore */
298 ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_STEPID;
299 if (tscadc_dev->tsc_cell != -1)
300 ctrl |= CNTRLREG_TSCENB | CNTRLREG_4WIRE;
301 tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
303 if (tscadc_dev->tsc_cell != -1)
304 tscadc_idle_config(tscadc_dev);
305 am335x_tsc_se_update(tscadc_dev);
306 restore = tscadc_readl(tscadc_dev, REG_CTRL);
307 tscadc_writel(tscadc_dev, REG_CTRL,
308 (restore | CNTRLREG_TSCSSENB));
310 tscadc_writel(tscadc_dev, REG_CLKDIV, tscadc_dev->clk_div);
315 static const struct dev_pm_ops tscadc_pm_ops = {
316 .suspend = tscadc_suspend,
317 .resume = tscadc_resume,
319 #define TSCADC_PM_OPS (&tscadc_pm_ops)
321 #define TSCADC_PM_OPS NULL
324 static const struct of_device_id ti_tscadc_dt_ids[] = {
325 { .compatible = "ti,am3359-tscadc", },
328 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);
330 static struct platform_driver ti_tscadc_driver = {
332 .name = "ti_am3359-tscadc",
333 .owner = THIS_MODULE,
335 .of_match_table = ti_tscadc_dt_ids,
337 .probe = ti_tscadc_probe,
338 .remove = ti_tscadc_remove,
342 module_platform_driver(ti_tscadc_driver);
344 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
345 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
346 MODULE_LICENSE("GPL");