// SPDX-License-Identifier: GPL-2.0 /* * i2c Support for Atmel's AT91 Two-Wire Interface (TWI) * * Copyright (C) 2011 Weinmann Medical GmbH * Author: Nikolaus Voss <n.voss@weinmann.de> * * Evolved from original work by: * Copyright (C) 2004 Rick Bronson * Converted to 2.6 by Andrew Victor <andrew@sanpeople.com> * * Borrowed heavily from original work by: * Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com> */ #include <linux/clk.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/io.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> #include <linux/pinctrl/consumer.h> #include "i2c-at91.h" unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) { return readl_relaxed(dev->base + reg); } void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) { writel_relaxed(val, dev->base + reg); } void at91_disable_twi_interrupts(struct at91_twi_dev *dev) { at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK); } void at91_twi_irq_save(struct at91_twi_dev *dev) { dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK; at91_disable_twi_interrupts(dev); } void at91_twi_irq_restore(struct at91_twi_dev *dev) { at91_twi_write(dev, AT91_TWI_IER, dev->imr); } void at91_init_twi_bus(struct at91_twi_dev *dev) { at91_disable_twi_interrupts(dev); at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST); if (dev->slave_detected) at91_init_twi_bus_slave(dev); else at91_init_twi_bus_master(dev); } static struct at91_twi_pdata at91rm9200_config = { .clk_max_div = 5, .clk_offset = 3, .has_unre_flag = true, }; static struct at91_twi_pdata at91sam9261_config = { .clk_max_div = 5, .clk_offset = 4, }; static struct at91_twi_pdata at91sam9260_config = { .clk_max_div = 7, .clk_offset = 4, }; static struct at91_twi_pdata at91sam9g20_config = { .clk_max_div = 7, .clk_offset = 4, }; static struct at91_twi_pdata at91sam9g10_config = { .clk_max_div = 7, .clk_offset = 4, }; static const struct platform_device_id at91_twi_devtypes[] = { { .name = "i2c-at91rm9200", .driver_data = (unsigned long) &at91rm9200_config, }, { .name = "i2c-at91sam9261", .driver_data = (unsigned long) &at91sam9261_config, }, { .name = "i2c-at91sam9260", .driver_data = (unsigned long) &at91sam9260_config, }, { .name = "i2c-at91sam9g20", .driver_data = (unsigned long) &at91sam9g20_config, }, { .name = "i2c-at91sam9g10", .driver_data = (unsigned long) &at91sam9g10_config, }, { /* sentinel */ } }; #if defined(CONFIG_OF) static struct at91_twi_pdata at91sam9x5_config = { .clk_max_div = 7, .clk_offset = 4, }; static struct at91_twi_pdata sama5d4_config = { .clk_max_div = 7, .clk_offset = 4, .has_hold_field = true, .has_dig_filtr = true, }; static struct at91_twi_pdata sama5d2_config = { .clk_max_div = 7, .clk_offset = 3, .has_unre_flag = true, .has_alt_cmd = true, .has_hold_field = true, .has_dig_filtr = true, .has_adv_dig_filtr = true, .has_ana_filtr = true, .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */ }; static struct at91_twi_pdata sam9x60_config = { .clk_max_div = 7, .clk_offset = 3, .has_unre_flag = true, .has_alt_cmd = true, .has_hold_field = true, .has_dig_filtr = true, .has_adv_dig_filtr = true, .has_ana_filtr = true, .has_clear_cmd = true, }; static const struct of_device_id atmel_twi_dt_ids[] = { { .compatible = "atmel,at91rm9200-i2c", .data = &at91rm9200_config, }, { .compatible = "atmel,at91sam9260-i2c", .data = &at91sam9260_config, }, { .compatible = "atmel,at91sam9261-i2c", .data = &at91sam9261_config, }, { .compatible = "atmel,at91sam9g20-i2c", .data = &at91sam9g20_config, }, { .compatible = "atmel,at91sam9g10-i2c", .data = &at91sam9g10_config, }, { .compatible = "atmel,at91sam9x5-i2c", .data = &at91sam9x5_config, }, { .compatible = "atmel,sama5d4-i2c", .data = &sama5d4_config, }, { .compatible = "atmel,sama5d2-i2c", .data = &sama5d2_config, }, { .compatible = "microchip,sam9x60-i2c", .data = &sam9x60_config, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids); #endif static struct at91_twi_pdata *at91_twi_get_driver_data( struct platform_device *pdev) { if (pdev->dev.of_node) { const struct of_device_id *match; match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node); if (!match) return NULL; return (struct at91_twi_pdata *)match->data; } return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data; } static int at91_twi_probe(struct platform_device *pdev) { struct at91_twi_dev *dev; struct resource *mem; int rc; u32 phy_addr; dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); if (!dev) return -ENOMEM; dev->dev = &pdev->dev; mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!mem) return -ENODEV; phy_addr = mem->start; dev->pdata = at91_twi_get_driver_data(pdev); if (!dev->pdata) return -ENODEV; dev->base = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(dev->base)) return PTR_ERR(dev->base); dev->irq = platform_get_irq(pdev, 0); if (dev->irq < 0) return dev->irq; platform_set_drvdata(pdev, dev); dev->clk = devm_clk_get(dev->dev, NULL); if (IS_ERR(dev->clk)) { dev_err(dev->dev, "no clock defined\n"); return -ENODEV; } clk_prepare_enable(dev->clk); snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); i2c_set_adapdata(&dev->adapter, dev); dev->adapter.owner = THIS_MODULE; dev->adapter.class = I2C_CLASS_DEPRECATED; dev->adapter.dev.parent = dev->dev; dev->adapter.nr = pdev->id; dev->adapter.timeout = AT91_I2C_TIMEOUT; dev->adapter.dev.of_node = pdev->dev.of_node; dev->slave_detected = i2c_detect_slave_mode(&pdev->dev); if (dev->slave_detected) rc = at91_twi_probe_slave(pdev, phy_addr, dev); else rc = at91_twi_probe_master(pdev, phy_addr, dev); if (rc) return rc; at91_init_twi_bus(dev); pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT); pm_runtime_use_autosuspend(dev->dev); pm_runtime_set_active(dev->dev); pm_runtime_enable(dev->dev); rc = i2c_add_numbered_adapter(&dev->adapter); if (rc) { clk_disable_unprepare(dev->clk); pm_runtime_disable(dev->dev); pm_runtime_set_suspended(dev->dev); return rc; } dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n", at91_twi_read(dev, AT91_TWI_VER)); return 0; } static void at91_twi_remove(struct platform_device *pdev) { struct at91_twi_dev *dev = platform_get_drvdata(pdev); i2c_del_adapter(&dev->adapter); clk_disable_unprepare(dev->clk); pm_runtime_disable(dev->dev); pm_runtime_set_suspended(dev->dev); } static int __maybe_unused at91_twi_runtime_suspend(struct device *dev) { struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); clk_disable_unprepare(twi_dev->clk); pinctrl_pm_select_sleep_state(dev); return 0; } static int __maybe_unused at91_twi_runtime_resume(struct device *dev) { struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); pinctrl_pm_select_default_state(dev); return clk_prepare_enable(twi_dev->clk); } static int __maybe_unused at91_twi_suspend_noirq(struct device *dev) { if (!pm_runtime_status_suspended(dev)) at91_twi_runtime_suspend(dev); return 0; } static int __maybe_unused at91_twi_resume_noirq(struct device *dev) { struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); int ret; if (!pm_runtime_status_suspended(dev)) { ret = at91_twi_runtime_resume(dev); if (ret) return ret; } pm_runtime_mark_last_busy(dev); pm_request_autosuspend(dev); at91_init_twi_bus(twi_dev); return 0; } static const struct dev_pm_ops __maybe_unused at91_twi_pm = { .suspend_noirq = at91_twi_suspend_noirq, .resume_noirq = at91_twi_resume_noirq, .runtime_suspend = at91_twi_runtime_suspend, .runtime_resume = at91_twi_runtime_resume, }; static struct platform_driver at91_twi_driver = { .probe = at91_twi_probe, .remove_new = at91_twi_remove, .id_table = at91_twi_devtypes, .driver = { .name = "at91_i2c", .of_match_table = of_match_ptr(atmel_twi_dt_ids), .pm = pm_ptr(&at91_twi_pm), }, }; static int __init at91_twi_init(void) { return platform_driver_register(&at91_twi_driver); } static void __exit at91_twi_exit(void) { platform_driver_unregister(&at91_twi_driver); } subsys_initcall(at91_twi_init); module_exit(at91_twi_exit); MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>"); MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:at91_i2c");