1 /* drivers/adc/chips/rk28_adc.c
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3 * This program is free software; you can redistribute it and/or modify
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4 * it under the terms of the GNU General Public License as published by
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5 * the Free Software Foundation; either version 2 of the License.
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7 #include <linux/adc.h>
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9 #include "../adc_priv.h"
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10 #include "rk28_adc.h"
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14 struct rk28_adc_device {
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18 struct resource *ioarea;
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19 struct adc_host *adc;
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21 static void rk28_adc_start(struct adc_host *adc)
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23 struct rk28_adc_device *dev = adc_priv(adc);
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26 writel(ADC_CTRL_IRQ_ENABLE|ADC_CTRL_POWER_UP|ADC_CTRL_START|ADC_CTRL_CH(chn),
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27 dev->regs + ADC_CTRL);
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29 static void rk28_adc_stop(struct adc_host *adc)
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31 struct rk28_adc_device *dev = adc_priv(adc);
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33 writel(ADC_CTRL_IRQ_STATUS, dev->regs + ADC_CTRL);
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35 static int rk28_adc_read(struct adc_host *adc)
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37 struct rk28_adc_device *dev = adc_priv(adc);
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39 udelay(SAMPLE_RATE);
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40 return readl(dev->regs + ADC_DATA) & ADC_DATA_MASK;
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42 static irqreturn_t rk28_adc_irq(int irq, void *data)
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44 struct rk28_adc_device *dev = data;
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45 adc_core_irq_handle(dev->adc);
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48 static const struct adc_ops rk28_adc_ops = {
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49 .start = rk28_adc_start,
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50 .stop = rk28_adc_stop,
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51 .read = rk28_adc_read,
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54 static void callback(struct adc_client *client, void *param, int result)
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56 dev_info(client->adc->dev, "[chn%d] async_read = %d\n", client->chn, result);
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59 static int rk28_adc_test(void)
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62 struct adc_client *client = adc_register(1, callback, NULL);
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66 adc_async_read(client);
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68 sync_read = adc_sync_read(client);
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69 dev_info(client->adc->dev, "[chn%d] sync_read = %d\n", client->chn, sync_read);
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72 adc_unregister(client);
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77 static int rk28_adc_probe(struct platform_device *pdev)
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79 struct adc_host *adc = NULL;
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80 struct rk28_adc_device *dev;
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81 struct resource *res;
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84 adc = adc_alloc_host(&pdev->dev, sizeof(struct rk28_adc_device), SARADC_CHN_MASK);
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87 adc->ops = &rk28_adc_ops;
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88 dev = adc_priv(adc);
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90 dev->irq = platform_get_irq(pdev, 0);
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91 if (dev->irq <= 0) {
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92 dev_err(&pdev->dev, "failed to get adc irq\n");
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97 ret = request_irq(dev->irq, rk28_adc_irq, 0, pdev->name, dev);
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99 dev_err(&pdev->dev, "failed to attach adc irq\n");
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102 dev->clk = clk_get(&pdev->dev, "saradc");
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103 if (IS_ERR(dev->clk)) {
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104 dev_err(&pdev->dev, "failed to get adc clock\n");
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105 ret = PTR_ERR(dev->clk);
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109 ret = clk_set_rate(dev->clk, ADC_CLK_RATE * 1000 * 1000);
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111 dev_err(&pdev->dev, "failed to set adc clk\n");
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114 clk_enable(dev->clk);
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116 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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118 dev_err(&pdev->dev, "cannot find IO resource\n");
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122 dev->ioarea = request_mem_region(res->start, (res->end - res->start) + 1,
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124 if(dev->ioarea == NULL) {
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125 dev_err(&pdev->dev, "cannot request IO\n");
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129 dev->regs = ioremap(res->start, (res->end - res->start) + 1);
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131 dev_err(&pdev->dev, "cannot map IO\n");
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135 platform_set_drvdata(pdev, dev);
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136 dev_info(&pdev->dev, "rk28 adc: driver initialized\n");
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143 release_resource(dev->ioarea);
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144 kfree(dev->ioarea);
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145 clk_disable(dev->clk);
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151 free_irq(dev->irq, dev);
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154 adc_free_host(dev->adc);
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158 static int rk28_adc_remove(struct platform_device *pdev)
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160 struct rk28_adc_device *dev = platform_get_drvdata(pdev);
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162 iounmap(dev->regs);
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163 release_resource(dev->ioarea);
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164 kfree(dev->ioarea);
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165 free_irq(dev->irq, dev);
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166 clk_disable(dev->clk);
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168 adc_free_host(dev->adc);
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174 static int rk28_adc_suspend(struct platform_device *pdev, pm_message_t state)
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176 struct rk28_adc_device *dev = platform_get_drvdata(pdev);
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178 dev->adc->is_suspended = 1;
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182 static int rk28_adc_resume(struct platform_device *pdev)
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184 struct rk28_adc_device *dev = platform_get_drvdata(pdev);
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186 dev->adc->is_suspended = 0;
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191 #define rk28_adc_suspend NULL
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192 #define rk28_adc_resume NULL
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195 static struct platform_driver rk28_adc_driver = {
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197 .name = "rk28-adc",
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198 .owner = THIS_MODULE,
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200 .probe = rk28_adc_probe,
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201 .remove = __devexit_p(rk28_adc_remove),
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202 .suspend = rk28_adc_suspend,
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203 .resume = rk28_adc_resume,
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206 static int __init rk28_adc_init(void)
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208 return platform_driver_register(&rk28_adc_driver);
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210 subsys_initcall(rk28_adc_init);
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212 static void __exit rk28_adc_exit(void)
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214 platform_driver_unregister(&rk28_adc_driver);
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216 module_exit(rk28_adc_exit);
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218 MODULE_DESCRIPTION("Driver for ADC");
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219 MODULE_AUTHOR("kfx, kfx@rock-chips.com");
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220 MODULE_LICENSE("GPL");
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