2 * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
4 * This program is free software; you can redistribute it and/or modify it under
5 * the terms of the GNU General Public License version 2 as published by the
6 * Free Software Foundation.
10 #include <linux/interrupt.h>
11 #include <linux/irqchip/chained_irq.h>
12 #include <linux/irqdesc.h>
13 #include <linux/irqdomain.h>
14 #include <linux/irq.h>
15 #include <linux/mfd/imx25-tsadc.h>
16 #include <linux/module.h>
18 #include <linux/of_platform.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
22 static struct regmap_config mx25_tsadc_regmap_config = {
30 static void mx25_tsadc_irq_handler(struct irq_desc *desc)
32 struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc);
33 struct irq_chip *chip = irq_desc_get_chip(desc);
36 chained_irq_enter(chip, desc);
38 regmap_read(tsadc->regs, MX25_TSC_TGSR, &status);
40 if (status & MX25_TGSR_GCQ_INT)
41 generic_handle_irq(irq_find_mapping(tsadc->domain, 1));
43 if (status & MX25_TGSR_TCQ_INT)
44 generic_handle_irq(irq_find_mapping(tsadc->domain, 0));
46 chained_irq_exit(chip, desc);
49 static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq,
50 irq_hw_number_t hwirq)
52 struct mx25_tsadc *tsadc = d->host_data;
54 irq_set_chip_data(irq, tsadc);
55 irq_set_chip_and_handler(irq, &dummy_irq_chip,
57 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
62 static const struct irq_domain_ops mx25_tsadc_domain_ops = {
63 .map = mx25_tsadc_domain_map,
64 .xlate = irq_domain_xlate_onecell,
67 static int mx25_tsadc_setup_irq(struct platform_device *pdev,
68 struct mx25_tsadc *tsadc)
70 struct device *dev = &pdev->dev;
71 struct device_node *np = dev->of_node;
74 irq = platform_get_irq(pdev, 0);
76 dev_err(dev, "Failed to get irq\n");
80 tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops,
83 dev_err(dev, "Failed to add irq domain\n");
87 irq_set_chained_handler_and_data(irq, mx25_tsadc_irq_handler, tsadc);
92 static int mx25_tsadc_unset_irq(struct platform_device *pdev)
94 struct mx25_tsadc *tsadc = platform_get_drvdata(pdev);
95 int irq = platform_get_irq(pdev, 0);
98 irq_set_chained_handler_and_data(irq, NULL, NULL);
99 irq_domain_remove(tsadc->domain);
105 static void mx25_tsadc_setup_clk(struct platform_device *pdev,
106 struct mx25_tsadc *tsadc)
111 * According to the datasheet the ADC clock should never
112 * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses
113 * a funny clock divider. To keep the ADC conversion time constant
114 * adapt the ADC internal clock divider to the IPG clock rate.
117 dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n",
118 clk_get_rate(tsadc->clk));
120 clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000);
121 dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div);
123 /* adc clock = IPG clock / (2 * div + 2) */
128 * the ADC clock divider changes its behaviour when values below 4
129 * are used: it is fixed to "/ 10" in this case
131 clk_div = max_t(unsigned, 4, clk_div);
133 dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n",
134 clk_get_rate(tsadc->clk) / (2 * clk_div + 2));
136 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR,
137 MX25_TGCR_ADCCLKCFG(0x1f),
138 MX25_TGCR_ADCCLKCFG(clk_div));
141 static int mx25_tsadc_probe(struct platform_device *pdev)
143 struct device *dev = &pdev->dev;
144 struct mx25_tsadc *tsadc;
145 struct resource *res;
149 tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL);
153 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
154 iomem = devm_ioremap_resource(dev, res);
156 return PTR_ERR(iomem);
158 tsadc->regs = devm_regmap_init_mmio(dev, iomem,
159 &mx25_tsadc_regmap_config);
160 if (IS_ERR(tsadc->regs)) {
161 dev_err(dev, "Failed to initialize regmap\n");
162 return PTR_ERR(tsadc->regs);
165 tsadc->clk = devm_clk_get(dev, "ipg");
166 if (IS_ERR(tsadc->clk)) {
167 dev_err(dev, "Failed to get ipg clock\n");
168 return PTR_ERR(tsadc->clk);
171 /* setup clock according to the datasheet */
172 mx25_tsadc_setup_clk(pdev, tsadc);
174 /* Enable clock and reset the component */
175 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN,
177 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST,
180 /* Setup powersaving mode, but enable internal reference voltage */
181 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK,
182 MX25_TGCR_POWERMODE_SAVE);
183 regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN,
186 ret = mx25_tsadc_setup_irq(pdev, tsadc);
190 platform_set_drvdata(pdev, tsadc);
192 ret = devm_of_platform_populate(dev);
199 mx25_tsadc_unset_irq(pdev);
204 static int mx25_tsadc_remove(struct platform_device *pdev)
206 mx25_tsadc_unset_irq(pdev);
211 static const struct of_device_id mx25_tsadc_ids[] = {
212 { .compatible = "fsl,imx25-tsadc" },
215 MODULE_DEVICE_TABLE(of, mx25_tsadc_ids);
217 static struct platform_driver mx25_tsadc_driver = {
219 .name = "mx25-tsadc",
220 .of_match_table = of_match_ptr(mx25_tsadc_ids),
222 .probe = mx25_tsadc_probe,
223 .remove = mx25_tsadc_remove,
225 module_platform_driver(mx25_tsadc_driver);
227 MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25");
228 MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
229 MODULE_LICENSE("GPL v2");
230 MODULE_ALIAS("platform:mx25-tsadc");