| // 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 int 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); |
| |
| return 0; |
| } |
| |
| 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 = 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"); |
