Andreas Larsson | ddb27f3 | 2013-04-17 14:36:50 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * Driver for Aeroflex Gaisler GRGPIO General Purpose I/O cores. |
| 3 | * |
| 4 | * 2013 (c) Aeroflex Gaisler AB |
| 5 | * |
| 6 | * This driver supports the GRGPIO GPIO core available in the GRLIB VHDL |
| 7 | * IP core library. |
| 8 | * |
| 9 | * Full documentation of the GRGPIO core can be found here: |
| 10 | * http://www.gaisler.com/products/grlib/grip.pdf |
| 11 | * |
| 12 | * See "Documentation/devicetree/bindings/gpio/gpio-grgpio.txt" for |
| 13 | * information on open firmware properties. |
| 14 | * |
| 15 | * This program is free software; you can redistribute it and/or modify it |
| 16 | * under the terms of the GNU General Public License as published by the |
| 17 | * Free Software Foundation; either version 2 of the License, or (at your |
| 18 | * option) any later version. |
| 19 | * |
| 20 | * Contributors: Andreas Larsson <andreas@gaisler.com> |
| 21 | */ |
| 22 | |
| 23 | #include <linux/kernel.h> |
| 24 | #include <linux/module.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/spinlock.h> |
| 27 | #include <linux/io.h> |
| 28 | #include <linux/of.h> |
| 29 | #include <linux/of_gpio.h> |
| 30 | #include <linux/of_platform.h> |
| 31 | #include <linux/gpio.h> |
| 32 | #include <linux/slab.h> |
| 33 | #include <linux/err.h> |
| 34 | #include <linux/basic_mmio_gpio.h> |
| 35 | |
| 36 | #define GRGPIO_MAX_NGPIO 32 |
| 37 | |
| 38 | #define GRGPIO_DATA 0x00 |
| 39 | #define GRGPIO_OUTPUT 0x04 |
| 40 | #define GRGPIO_DIR 0x08 |
| 41 | #define GRGPIO_IMASK 0x0c |
| 42 | #define GRGPIO_IPOL 0x10 |
| 43 | #define GRGPIO_IEDGE 0x14 |
| 44 | #define GRGPIO_BYPASS 0x18 |
| 45 | #define GRGPIO_IMAP_BASE 0x20 |
| 46 | |
| 47 | struct grgpio_priv { |
| 48 | struct bgpio_chip bgc; |
| 49 | void __iomem *regs; |
| 50 | struct device *dev; |
| 51 | }; |
| 52 | |
| 53 | static inline struct grgpio_priv *grgpio_gc_to_priv(struct gpio_chip *gc) |
| 54 | { |
| 55 | struct bgpio_chip *bgc = to_bgpio_chip(gc); |
| 56 | |
| 57 | return container_of(bgc, struct grgpio_priv, bgc); |
| 58 | } |
| 59 | |
| 60 | static int grgpio_probe(struct platform_device *ofdev) |
| 61 | { |
| 62 | struct device_node *np = ofdev->dev.of_node; |
| 63 | void __iomem *regs; |
| 64 | struct gpio_chip *gc; |
| 65 | struct bgpio_chip *bgc; |
| 66 | struct grgpio_priv *priv; |
| 67 | struct resource *res; |
| 68 | int err; |
| 69 | u32 prop; |
| 70 | |
| 71 | priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL); |
| 72 | if (!priv) |
| 73 | return -ENOMEM; |
| 74 | |
| 75 | res = platform_get_resource(ofdev, IORESOURCE_MEM, 0); |
| 76 | regs = devm_ioremap_resource(&ofdev->dev, res); |
| 77 | if (IS_ERR(regs)) |
| 78 | return PTR_ERR(regs); |
| 79 | |
| 80 | bgc = &priv->bgc; |
| 81 | err = bgpio_init(bgc, &ofdev->dev, 4, regs + GRGPIO_DATA, |
| 82 | regs + GRGPIO_OUTPUT, NULL, regs + GRGPIO_DIR, NULL, |
| 83 | BGPIOF_BIG_ENDIAN_BYTE_ORDER); |
| 84 | if (err) { |
| 85 | dev_err(&ofdev->dev, "bgpio_init() failed\n"); |
| 86 | return err; |
| 87 | } |
| 88 | |
| 89 | priv->regs = regs; |
| 90 | priv->dev = &ofdev->dev; |
| 91 | |
| 92 | gc = &bgc->gc; |
| 93 | gc->of_node = np; |
| 94 | gc->owner = THIS_MODULE; |
| 95 | gc->label = np->full_name; |
| 96 | gc->base = -1; |
| 97 | |
| 98 | err = of_property_read_u32(np, "nbits", &prop); |
| 99 | if (err || prop <= 0 || prop > GRGPIO_MAX_NGPIO) { |
| 100 | gc->ngpio = GRGPIO_MAX_NGPIO; |
| 101 | dev_dbg(&ofdev->dev, |
| 102 | "No or invalid nbits property: assume %d\n", gc->ngpio); |
| 103 | } else { |
| 104 | gc->ngpio = prop; |
| 105 | } |
| 106 | |
| 107 | platform_set_drvdata(ofdev, priv); |
| 108 | |
| 109 | err = gpiochip_add(gc); |
| 110 | if (err) { |
| 111 | dev_err(&ofdev->dev, "Could not add gpiochip\n"); |
| 112 | return err; |
| 113 | } |
| 114 | |
| 115 | dev_info(&ofdev->dev, "regs=0x%p, base=%d, ngpio=%d\n", |
| 116 | priv->regs, gc->base, gc->ngpio); |
| 117 | |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | static int grgpio_remove(struct platform_device *ofdev) |
| 122 | { |
| 123 | struct grgpio_priv *priv = platform_get_drvdata(ofdev); |
| 124 | |
| 125 | return gpiochip_remove(&priv->bgc.gc); |
| 126 | } |
| 127 | |
| 128 | static struct of_device_id grgpio_match[] = { |
| 129 | {.name = "GAISLER_GPIO"}, |
| 130 | {.name = "01_01a"}, |
| 131 | {}, |
| 132 | }; |
| 133 | |
| 134 | MODULE_DEVICE_TABLE(of, grgpio_match); |
| 135 | |
| 136 | static struct platform_driver grgpio_driver = { |
| 137 | .driver = { |
| 138 | .name = "grgpio", |
| 139 | .owner = THIS_MODULE, |
| 140 | .of_match_table = grgpio_match, |
| 141 | }, |
| 142 | .probe = grgpio_probe, |
| 143 | .remove = grgpio_remove, |
| 144 | }; |
| 145 | module_platform_driver(grgpio_driver); |
| 146 | |
| 147 | MODULE_AUTHOR("Aeroflex Gaisler AB."); |
| 148 | MODULE_DESCRIPTION("Driver for Aeroflex Gaisler GRGPIO"); |
| 149 | MODULE_LICENSE("GPL"); |