/* * Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <mpa@pengutronix.de> * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License version 2 as published by the * Free Software Foundation. */ #include <linux/clk.h> #include <linux/interrupt.h> #include <linux/irqchip/chained_irq.h> #include <linux/irqdesc.h> #include <linux/irqdomain.h> #include <linux/irq.h> #include <linux/mfd/imx25-tsadc.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/regmap.h> static struct regmap_config mx25_tsadc_regmap_config = { .fast_io = true, .max_register = 8, .reg_bits = 32, .val_bits = 32, .reg_stride = 4, }; static void mx25_tsadc_irq_handler(struct irq_desc *desc) { struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc); struct irq_chip *chip = irq_desc_get_chip(desc); u32 status; chained_irq_enter(chip, desc); regmap_read(tsadc->regs, MX25_TSC_TGSR, &status); if (status & MX25_TGSR_GCQ_INT) generic_handle_irq(irq_find_mapping(tsadc->domain, 1)); if (status & MX25_TGSR_TCQ_INT) generic_handle_irq(irq_find_mapping(tsadc->domain, 0)); chained_irq_exit(chip, desc); } static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) { struct mx25_tsadc *tsadc = d->host_data; irq_set_chip_data(irq, tsadc); irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_level_irq); irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE); return 0; } static struct irq_domain_ops mx25_tsadc_domain_ops = { .map = mx25_tsadc_domain_map, .xlate = irq_domain_xlate_onecell, }; static int mx25_tsadc_setup_irq(struct platform_device *pdev, struct mx25_tsadc *tsadc) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; int irq; irq = platform_get_irq(pdev, 0); if (irq <= 0) { dev_err(dev, "Failed to get irq\n"); return irq; } tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops, tsadc); if (!tsadc->domain) { dev_err(dev, "Failed to add irq domain\n"); return -ENOMEM; } irq_set_chained_handler(irq, mx25_tsadc_irq_handler); irq_set_handler_data(irq, tsadc); return 0; } static void mx25_tsadc_setup_clk(struct platform_device *pdev, struct mx25_tsadc *tsadc) { unsigned clk_div; /* * According to the datasheet the ADC clock should never * exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses * a funny clock divider. To keep the ADC conversion time constant * adapt the ADC internal clock divider to the IPG clock rate. */ dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n", clk_get_rate(tsadc->clk)); clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000); dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div); /* adc clock = IPG clock / (2 * div + 2) */ clk_div -= 2; clk_div /= 2; /* * the ADC clock divider changes its behaviour when values below 4 * are used: it is fixed to "/ 10" in this case */ clk_div = max_t(unsigned, 4, clk_div); dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n", clk_get_rate(tsadc->clk) / (2 * clk_div + 2)); regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_ADCCLKCFG(0x1f), MX25_TGCR_ADCCLKCFG(clk_div)); } static int mx25_tsadc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct mx25_tsadc *tsadc; struct resource *res; int ret; void __iomem *iomem; tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL); if (!tsadc) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); iomem = devm_ioremap_resource(dev, res); if (IS_ERR(iomem)) return PTR_ERR(iomem); tsadc->regs = devm_regmap_init_mmio(dev, iomem, &mx25_tsadc_regmap_config); if (IS_ERR(tsadc->regs)) { dev_err(dev, "Failed to initialize regmap\n"); return PTR_ERR(tsadc->regs); } tsadc->clk = devm_clk_get(dev, "ipg"); if (IS_ERR(tsadc->clk)) { dev_err(dev, "Failed to get ipg clock\n"); return PTR_ERR(tsadc->clk); } /* setup clock according to the datasheet */ mx25_tsadc_setup_clk(pdev, tsadc); /* Enable clock and reset the component */ regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN, MX25_TGCR_CLK_EN); regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST, MX25_TGCR_TSC_RST); /* Setup powersaving mode, but enable internal reference voltage */ regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK, MX25_TGCR_POWERMODE_SAVE); regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN, MX25_TGCR_INTREFEN); ret = mx25_tsadc_setup_irq(pdev, tsadc); if (ret) return ret; platform_set_drvdata(pdev, tsadc); of_platform_populate(np, NULL, NULL, dev); return 0; } static const struct of_device_id mx25_tsadc_ids[] = { { .compatible = "fsl,imx25-tsadc" }, { /* Sentinel */ } }; static struct platform_driver mx25_tsadc_driver = { .driver = { .name = "mx25-tsadc", .of_match_table = of_match_ptr(mx25_tsadc_ids), }, .probe = mx25_tsadc_probe, }; module_platform_driver(mx25_tsadc_driver); MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25"); MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:mx25-tsadc");