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209 lines
5.3 KiB
209 lines
5.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2014-2015 Pengutronix, Markus Pargmann <[email protected]> |
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*/ |
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#include <linux/clk.h> |
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#include <linux/interrupt.h> |
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#include <linux/irqchip/chained_irq.h> |
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#include <linux/irqdesc.h> |
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#include <linux/irqdomain.h> |
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#include <linux/irq.h> |
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#include <linux/mfd/imx25-tsadc.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/of_platform.h> |
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#include <linux/platform_device.h> |
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#include <linux/regmap.h> |
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static struct regmap_config mx25_tsadc_regmap_config = { |
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.fast_io = true, |
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.max_register = 8, |
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.reg_bits = 32, |
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.val_bits = 32, |
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.reg_stride = 4, |
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}; |
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static void mx25_tsadc_irq_handler(struct irq_desc *desc) |
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{ |
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struct mx25_tsadc *tsadc = irq_desc_get_handler_data(desc); |
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struct irq_chip *chip = irq_desc_get_chip(desc); |
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u32 status; |
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chained_irq_enter(chip, desc); |
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regmap_read(tsadc->regs, MX25_TSC_TGSR, &status); |
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if (status & MX25_TGSR_GCQ_INT) |
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generic_handle_domain_irq(tsadc->domain, 1); |
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if (status & MX25_TGSR_TCQ_INT) |
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generic_handle_domain_irq(tsadc->domain, 0); |
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chained_irq_exit(chip, desc); |
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} |
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static int mx25_tsadc_domain_map(struct irq_domain *d, unsigned int irq, |
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irq_hw_number_t hwirq) |
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{ |
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struct mx25_tsadc *tsadc = d->host_data; |
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irq_set_chip_data(irq, tsadc); |
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irq_set_chip_and_handler(irq, &dummy_irq_chip, |
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handle_level_irq); |
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irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE); |
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return 0; |
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} |
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static const struct irq_domain_ops mx25_tsadc_domain_ops = { |
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.map = mx25_tsadc_domain_map, |
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.xlate = irq_domain_xlate_onecell, |
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}; |
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static int mx25_tsadc_setup_irq(struct platform_device *pdev, |
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struct mx25_tsadc *tsadc) |
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{ |
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struct device *dev = &pdev->dev; |
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struct device_node *np = dev->of_node; |
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int irq; |
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irq = platform_get_irq(pdev, 0); |
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if (irq <= 0) |
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return irq; |
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tsadc->domain = irq_domain_add_simple(np, 2, 0, &mx25_tsadc_domain_ops, |
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tsadc); |
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if (!tsadc->domain) { |
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dev_err(dev, "Failed to add irq domain\n"); |
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return -ENOMEM; |
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} |
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irq_set_chained_handler_and_data(irq, mx25_tsadc_irq_handler, tsadc); |
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return 0; |
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} |
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static void mx25_tsadc_setup_clk(struct platform_device *pdev, |
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struct mx25_tsadc *tsadc) |
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{ |
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unsigned clk_div; |
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/* |
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* According to the datasheet the ADC clock should never |
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* exceed 1,75 MHz. Base clock is the IPG and the ADC unit uses |
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* a funny clock divider. To keep the ADC conversion time constant |
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* adapt the ADC internal clock divider to the IPG clock rate. |
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*/ |
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dev_dbg(&pdev->dev, "Found master clock at %lu Hz\n", |
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clk_get_rate(tsadc->clk)); |
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clk_div = DIV_ROUND_UP(clk_get_rate(tsadc->clk), 1750000); |
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dev_dbg(&pdev->dev, "Setting up ADC clock divider to %u\n", clk_div); |
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/* adc clock = IPG clock / (2 * div + 2) */ |
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clk_div -= 2; |
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clk_div /= 2; |
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/* |
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* the ADC clock divider changes its behaviour when values below 4 |
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* are used: it is fixed to "/ 10" in this case |
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*/ |
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clk_div = max_t(unsigned, 4, clk_div); |
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dev_dbg(&pdev->dev, "Resulting ADC conversion clock at %lu Hz\n", |
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clk_get_rate(tsadc->clk) / (2 * clk_div + 2)); |
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regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, |
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MX25_TGCR_ADCCLKCFG(0x1f), |
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MX25_TGCR_ADCCLKCFG(clk_div)); |
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} |
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static int mx25_tsadc_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct mx25_tsadc *tsadc; |
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struct resource *res; |
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int ret; |
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void __iomem *iomem; |
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tsadc = devm_kzalloc(dev, sizeof(*tsadc), GFP_KERNEL); |
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if (!tsadc) |
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return -ENOMEM; |
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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iomem = devm_ioremap_resource(dev, res); |
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if (IS_ERR(iomem)) |
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return PTR_ERR(iomem); |
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tsadc->regs = devm_regmap_init_mmio(dev, iomem, |
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&mx25_tsadc_regmap_config); |
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if (IS_ERR(tsadc->regs)) { |
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dev_err(dev, "Failed to initialize regmap\n"); |
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return PTR_ERR(tsadc->regs); |
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} |
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tsadc->clk = devm_clk_get(dev, "ipg"); |
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if (IS_ERR(tsadc->clk)) { |
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dev_err(dev, "Failed to get ipg clock\n"); |
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return PTR_ERR(tsadc->clk); |
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} |
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/* setup clock according to the datasheet */ |
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mx25_tsadc_setup_clk(pdev, tsadc); |
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/* Enable clock and reset the component */ |
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regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_CLK_EN, |
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MX25_TGCR_CLK_EN); |
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regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_TSC_RST, |
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MX25_TGCR_TSC_RST); |
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/* Setup powersaving mode, but enable internal reference voltage */ |
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regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_POWERMODE_MASK, |
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MX25_TGCR_POWERMODE_SAVE); |
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regmap_update_bits(tsadc->regs, MX25_TSC_TGCR, MX25_TGCR_INTREFEN, |
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MX25_TGCR_INTREFEN); |
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ret = mx25_tsadc_setup_irq(pdev, tsadc); |
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if (ret) |
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return ret; |
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platform_set_drvdata(pdev, tsadc); |
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return devm_of_platform_populate(dev); |
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} |
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static int mx25_tsadc_remove(struct platform_device *pdev) |
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{ |
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struct mx25_tsadc *tsadc = platform_get_drvdata(pdev); |
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int irq = platform_get_irq(pdev, 0); |
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if (irq) { |
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irq_set_chained_handler_and_data(irq, NULL, NULL); |
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irq_domain_remove(tsadc->domain); |
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} |
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return 0; |
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} |
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static const struct of_device_id mx25_tsadc_ids[] = { |
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{ .compatible = "fsl,imx25-tsadc" }, |
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{ /* Sentinel */ } |
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}; |
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MODULE_DEVICE_TABLE(of, mx25_tsadc_ids); |
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static struct platform_driver mx25_tsadc_driver = { |
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.driver = { |
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.name = "mx25-tsadc", |
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.of_match_table = mx25_tsadc_ids, |
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}, |
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.probe = mx25_tsadc_probe, |
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.remove = mx25_tsadc_remove, |
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}; |
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module_platform_driver(mx25_tsadc_driver); |
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MODULE_DESCRIPTION("MFD for ADC/TSC for Freescale mx25"); |
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MODULE_AUTHOR("Markus Pargmann <[email protected]>"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:mx25-tsadc");
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