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Diffstat (limited to 'drivers/i2c/busses/i2c-at91-core.c')
-rw-r--r--drivers/i2c/busses/i2c-at91-core.c376
1 files changed, 376 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
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index 000000000000..8d55cdd69ff4
--- /dev/null
+++ b/drivers/i2c/busses/i2c-at91-core.c
@@ -0,0 +1,376 @@
+// 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,
+ .has_alt_cmd = false,
+ .has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9261_config = {
+ .clk_max_div = 5,
+ .clk_offset = 4,
+ .has_unre_flag = false,
+ .has_alt_cmd = false,
+ .has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9260_config = {
+ .clk_max_div = 7,
+ .clk_offset = 4,
+ .has_unre_flag = false,
+ .has_alt_cmd = false,
+ .has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9g20_config = {
+ .clk_max_div = 7,
+ .clk_offset = 4,
+ .has_unre_flag = false,
+ .has_alt_cmd = false,
+ .has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9g10_config = {
+ .clk_max_div = 7,
+ .clk_offset = 4,
+ .has_unre_flag = false,
+ .has_alt_cmd = false,
+ .has_hold_field = false,
+};
+
+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,
+ .has_unre_flag = false,
+ .has_alt_cmd = false,
+ .has_hold_field = false,
+};
+
+static struct at91_twi_pdata sama5d4_config = {
+ .clk_max_div = 7,
+ .clk_offset = 4,
+ .has_unre_flag = false,
+ .has_alt_cmd = false,
+ .has_hold_field = true,
+};
+
+static struct at91_twi_pdata sama5d2_config = {
+ .clk_max_div = 7,
+ .clk_offset = 4,
+ .has_unre_flag = true,
+ .has_alt_cmd = true,
+ .has_hold_field = 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,
+ }, {
+ /* 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");
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.