projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 5c41f11c CP |
1 | /* |
| 2 | * Driver for Atmel Flexcom | |
| 3 | * | |
| 4 | * Copyright (C) 2015 Atmel Corporation | |
| 5 | * | |
| 6 | * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com> | |
| 7 | * | |
| 8 | * This program is free software; you can redistribute it and/or modify | |
| 9 | * it under the terms of the GNU General Public License version 2 as | |
| 10 | * published by the Free Software Foundation. | |
| 11 | * | |
| 12 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
| 13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 15 | * more details. | |
| 16 | * | |
| 17 | * You should have received a copy of the GNU General Public License along with | |
| 18 | * this program. If not, see <http://www.gnu.org/licenses/>. | |
| 19 | */ | |
| 20 | ||
| 21 | #include <linux/module.h> | |
| 22 | #include <linux/types.h> | |
| 23 | #include <linux/kernel.h> | |
| 24 | #include <linux/platform_device.h> | |
| 25 | #include <linux/of.h> | |
| 26 | #include <linux/of_platform.h> | |
| 27 | #include <linux/err.h> | |
| 28 | #include <linux/io.h> | |
| 29 | #include <linux/clk.h> | |
| 30 | #include <dt-bindings/mfd/atmel-flexcom.h> | |
| 31 | ||
| 32 | /* I/O register offsets */ | |
| 33 | #define FLEX_MR 0x0 /* Mode Register */ | |
| 34 | #define FLEX_VERSION 0xfc /* Version Register */ | |
| 35 | ||
| 36 | /* Mode Register bit fields */ | |
| 37 | #define FLEX_MR_OPMODE_OFFSET (0) /* Operating Mode */ | |
| 38 | #define FLEX_MR_OPMODE_MASK (0x3 << FLEX_MR_OPMODE_OFFSET) | |
| 39 | #define FLEX_MR_OPMODE(opmode) (((opmode) << FLEX_MR_OPMODE_OFFSET) & \ | |
| 40 | FLEX_MR_OPMODE_MASK) | |
| 41 | ||
| 42 | ||
| 43 | static int atmel_flexcom_probe(struct platform_device *pdev) | |
| 44 | { | |
| 45 | struct device_node *np = pdev->dev.of_node; | |
| 46 | struct clk *clk; | |
| 47 | struct resource *res; | |
| 48 | void __iomem *base; | |
| 49 | u32 opmode; | |
| 50 | int err; | |
| 51 | ||
| 52 | err = of_property_read_u32(np, "atmel,flexcom-mode", &opmode); | |
| 53 | if (err) | |
| 54 | return err; | |
| 55 | ||
| 56 | if (opmode < ATMEL_FLEXCOM_MODE_USART || | |
| 57 | opmode > ATMEL_FLEXCOM_MODE_TWI) | |
| 58 | return -EINVAL; | |
| 59 | ||
| 60 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
| 61 | base = devm_ioremap_resource(&pdev->dev, res); | |
| 62 | if (IS_ERR(base)) | |
| 63 | return PTR_ERR(base); | |
| 64 | ||
| 65 | clk = devm_clk_get(&pdev->dev, NULL); | |
| 66 | if (IS_ERR(clk)) | |
| 67 | return PTR_ERR(clk); | |
| 68 | ||
| 69 | err = clk_prepare_enable(clk); | |
| 70 | if (err) | |
| 71 | return err; | |
| 72 | ||
| 73 | /* | |
| 74 | * Set the Operating Mode in the Mode Register: only the selected device | |
| 75 | * is clocked. Hence, registers of the other serial devices remain | |
| 76 | * inaccessible and are read as zero. Also the external I/O lines of the | |
| 77 | * Flexcom are muxed to reach the selected device. | |
| 78 | */ | |
| 79 | writel(FLEX_MR_OPMODE(opmode), base + FLEX_MR); | |
| 80 | ||
| 81 | clk_disable_unprepare(clk); | |
| 82 | ||
| 83 | return of_platform_populate(np, NULL, NULL, &pdev->dev); | |
| 84 | } | |
| 85 | ||
| 86 | static const struct of_device_id atmel_flexcom_of_match[] = { | |
| 87 | { .compatible = "atmel,sama5d2-flexcom" }, | |
| 88 | { /* sentinel */ } | |
| 89 | }; | |
| 90 | MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match); | |
| 91 | ||
| 92 | static struct platform_driver atmel_flexcom_driver = { | |
| 93 | .probe = atmel_flexcom_probe, | |
| 94 | .driver = { | |
| 95 | .name = "atmel_flexcom", | |
| 96 | .of_match_table = atmel_flexcom_of_match, | |
| 97 | }, | |
| 98 | }; | |
| 99 | ||
| 100 | module_platform_driver(atmel_flexcom_driver); | |
| 101 | ||
| 102 | MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>"); | |
| 103 | MODULE_DESCRIPTION("Atmel Flexcom MFD driver"); | |
| 104 | MODULE_LICENSE("GPL v2"); |