diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-at91-core.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-at91-core.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c new file mode 100644 index 000000000..e14edd236 --- /dev/null +++ b/drivers/i2c/busses/i2c-at91-core.c @@ -0,0 +1,377 @@ +// 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; +} + +#ifdef CONFIG_PM + +static int 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 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 at91_twi_suspend_noirq(struct device *dev) +{ + if (!pm_runtime_status_suspended(dev)) + at91_twi_runtime_suspend(dev); + + return 0; +} + +static int 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 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, +}; + +#define at91_twi_pm_ops (&at91_twi_pm) +#else +#define at91_twi_pm_ops NULL +#endif + +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 = at91_twi_pm_ops, + }, +}; + +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"); |