Thomas Gleixner | 2874c5f | 2019-05-27 08:55:01 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Daniel Hellstrom | b4a034d | 2013-02-25 22:51:37 -0800 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2013 Aeroflex Gaisler |
| 4 | * |
| 5 | * This driver supports the APBPS2 PS/2 core available in the GRLIB |
| 6 | * VHDL IP core library. |
| 7 | * |
| 8 | * Full documentation of the APBPS2 core can be found here: |
| 9 | * http://www.gaisler.com/products/grlib/grip.pdf |
| 10 | * |
| 11 | * See "Documentation/devicetree/bindings/input/ps2keyb-mouse-apbps2.txt" for |
| 12 | * information on open firmware properties. |
| 13 | * |
Daniel Hellstrom | b4a034d | 2013-02-25 22:51:37 -0800 | [diff] [blame] | 14 | * Contributors: Daniel Hellstrom <daniel@gaisler.com> |
| 15 | */ |
| 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/of_device.h> |
| 18 | #include <linux/module.h> |
| 19 | #include <linux/serio.h> |
| 20 | #include <linux/errno.h> |
| 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/of_irq.h> |
| 23 | #include <linux/device.h> |
| 24 | #include <linux/delay.h> |
| 25 | #include <linux/err.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/string.h> |
| 28 | #include <linux/kernel.h> |
| 29 | #include <linux/io.h> |
| 30 | |
| 31 | struct apbps2_regs { |
| 32 | u32 __iomem data; /* 0x00 */ |
| 33 | u32 __iomem status; /* 0x04 */ |
| 34 | u32 __iomem ctrl; /* 0x08 */ |
| 35 | u32 __iomem reload; /* 0x0c */ |
| 36 | }; |
| 37 | |
| 38 | #define APBPS2_STATUS_DR (1<<0) |
| 39 | #define APBPS2_STATUS_PE (1<<1) |
| 40 | #define APBPS2_STATUS_FE (1<<2) |
| 41 | #define APBPS2_STATUS_KI (1<<3) |
| 42 | #define APBPS2_STATUS_RF (1<<4) |
| 43 | #define APBPS2_STATUS_TF (1<<5) |
| 44 | #define APBPS2_STATUS_TCNT (0x1f<<22) |
| 45 | #define APBPS2_STATUS_RCNT (0x1f<<27) |
| 46 | |
| 47 | #define APBPS2_CTRL_RE (1<<0) |
| 48 | #define APBPS2_CTRL_TE (1<<1) |
| 49 | #define APBPS2_CTRL_RI (1<<2) |
| 50 | #define APBPS2_CTRL_TI (1<<3) |
| 51 | |
| 52 | struct apbps2_priv { |
| 53 | struct serio *io; |
| 54 | struct apbps2_regs *regs; |
| 55 | }; |
| 56 | |
| 57 | static int apbps2_idx; |
| 58 | |
| 59 | static irqreturn_t apbps2_isr(int irq, void *dev_id) |
| 60 | { |
| 61 | struct apbps2_priv *priv = dev_id; |
| 62 | unsigned long status, data, rxflags; |
| 63 | irqreturn_t ret = IRQ_NONE; |
| 64 | |
| 65 | while ((status = ioread32be(&priv->regs->status)) & APBPS2_STATUS_DR) { |
| 66 | data = ioread32be(&priv->regs->data); |
| 67 | rxflags = (status & APBPS2_STATUS_PE) ? SERIO_PARITY : 0; |
| 68 | rxflags |= (status & APBPS2_STATUS_FE) ? SERIO_FRAME : 0; |
| 69 | |
| 70 | /* clear error bits? */ |
| 71 | if (rxflags) |
| 72 | iowrite32be(0, &priv->regs->status); |
| 73 | |
| 74 | serio_interrupt(priv->io, data, rxflags); |
| 75 | |
| 76 | ret = IRQ_HANDLED; |
| 77 | } |
| 78 | |
| 79 | return ret; |
| 80 | } |
| 81 | |
| 82 | static int apbps2_write(struct serio *io, unsigned char val) |
| 83 | { |
| 84 | struct apbps2_priv *priv = io->port_data; |
| 85 | unsigned int tleft = 10000; /* timeout in 100ms */ |
| 86 | |
| 87 | /* delay until PS/2 controller has room for more chars */ |
| 88 | while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) && tleft--) |
| 89 | udelay(10); |
| 90 | |
| 91 | if ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) == 0) { |
| 92 | iowrite32be(val, &priv->regs->data); |
| 93 | |
| 94 | iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI | APBPS2_CTRL_TE, |
| 95 | &priv->regs->ctrl); |
| 96 | return 0; |
| 97 | } |
| 98 | |
| 99 | return -ETIMEDOUT; |
| 100 | } |
| 101 | |
| 102 | static int apbps2_open(struct serio *io) |
| 103 | { |
| 104 | struct apbps2_priv *priv = io->port_data; |
| 105 | int limit; |
| 106 | unsigned long tmp; |
| 107 | |
| 108 | /* clear error flags */ |
| 109 | iowrite32be(0, &priv->regs->status); |
| 110 | |
| 111 | /* Clear old data if available (unlikely) */ |
| 112 | limit = 1024; |
| 113 | while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_DR) && --limit) |
| 114 | tmp = ioread32be(&priv->regs->data); |
| 115 | |
| 116 | /* Enable reciever and it's interrupt */ |
| 117 | iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI, &priv->regs->ctrl); |
| 118 | |
| 119 | return 0; |
| 120 | } |
| 121 | |
| 122 | static void apbps2_close(struct serio *io) |
| 123 | { |
| 124 | struct apbps2_priv *priv = io->port_data; |
| 125 | |
| 126 | /* stop interrupts at PS/2 HW level */ |
| 127 | iowrite32be(0, &priv->regs->ctrl); |
| 128 | } |
| 129 | |
| 130 | /* Initialize one APBPS2 PS/2 core */ |
| 131 | static int apbps2_of_probe(struct platform_device *ofdev) |
| 132 | { |
| 133 | struct apbps2_priv *priv; |
| 134 | int irq, err; |
| 135 | u32 freq_hz; |
| 136 | struct resource *res; |
| 137 | |
| 138 | priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL); |
| 139 | if (!priv) { |
| 140 | dev_err(&ofdev->dev, "memory allocation failed\n"); |
| 141 | return -ENOMEM; |
| 142 | } |
| 143 | |
| 144 | /* Find Device Address */ |
| 145 | res = platform_get_resource(ofdev, IORESOURCE_MEM, 0); |
Sachin Kamat | e07a894 | 2013-04-15 13:38:07 -0700 | [diff] [blame] | 146 | priv->regs = devm_ioremap_resource(&ofdev->dev, res); |
| 147 | if (IS_ERR(priv->regs)) |
| 148 | return PTR_ERR(priv->regs); |
Daniel Hellstrom | b4a034d | 2013-02-25 22:51:37 -0800 | [diff] [blame] | 149 | |
| 150 | /* Reset hardware, disable interrupt */ |
| 151 | iowrite32be(0, &priv->regs->ctrl); |
| 152 | |
| 153 | /* IRQ */ |
| 154 | irq = irq_of_parse_and_map(ofdev->dev.of_node, 0); |
| 155 | err = devm_request_irq(&ofdev->dev, irq, apbps2_isr, |
| 156 | IRQF_SHARED, "apbps2", priv); |
| 157 | if (err) { |
| 158 | dev_err(&ofdev->dev, "request IRQ%d failed\n", irq); |
| 159 | return err; |
| 160 | } |
| 161 | |
| 162 | /* Get core frequency */ |
| 163 | if (of_property_read_u32(ofdev->dev.of_node, "freq", &freq_hz)) { |
| 164 | dev_err(&ofdev->dev, "unable to get core frequency\n"); |
| 165 | return -EINVAL; |
| 166 | } |
| 167 | |
| 168 | /* Set reload register to core freq in kHz/10 */ |
| 169 | iowrite32be(freq_hz / 10000, &priv->regs->reload); |
| 170 | |
| 171 | priv->io = kzalloc(sizeof(struct serio), GFP_KERNEL); |
| 172 | if (!priv->io) |
| 173 | return -ENOMEM; |
| 174 | |
| 175 | priv->io->id.type = SERIO_8042; |
| 176 | priv->io->open = apbps2_open; |
| 177 | priv->io->close = apbps2_close; |
| 178 | priv->io->write = apbps2_write; |
| 179 | priv->io->port_data = priv; |
| 180 | strlcpy(priv->io->name, "APBPS2 PS/2", sizeof(priv->io->name)); |
| 181 | snprintf(priv->io->phys, sizeof(priv->io->phys), |
| 182 | "apbps2_%d", apbps2_idx++); |
| 183 | |
| 184 | dev_info(&ofdev->dev, "irq = %d, base = 0x%p\n", irq, priv->regs); |
| 185 | |
| 186 | serio_register_port(priv->io); |
| 187 | |
| 188 | platform_set_drvdata(ofdev, priv); |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | static int apbps2_of_remove(struct platform_device *of_dev) |
| 194 | { |
| 195 | struct apbps2_priv *priv = platform_get_drvdata(of_dev); |
| 196 | |
| 197 | serio_unregister_port(priv->io); |
| 198 | |
| 199 | return 0; |
| 200 | } |
| 201 | |
Jingoo Han | 051f7de | 2014-05-07 13:04:50 -0700 | [diff] [blame] | 202 | static const struct of_device_id apbps2_of_match[] = { |
Daniel Hellstrom | b4a034d | 2013-02-25 22:51:37 -0800 | [diff] [blame] | 203 | { .name = "GAISLER_APBPS2", }, |
| 204 | { .name = "01_060", }, |
| 205 | {} |
| 206 | }; |
| 207 | |
| 208 | MODULE_DEVICE_TABLE(of, apbps2_of_match); |
| 209 | |
| 210 | static struct platform_driver apbps2_of_driver = { |
| 211 | .driver = { |
| 212 | .name = "grlib-apbps2", |
Daniel Hellstrom | b4a034d | 2013-02-25 22:51:37 -0800 | [diff] [blame] | 213 | .of_match_table = apbps2_of_match, |
| 214 | }, |
| 215 | .probe = apbps2_of_probe, |
| 216 | .remove = apbps2_of_remove, |
| 217 | }; |
| 218 | |
| 219 | module_platform_driver(apbps2_of_driver); |
| 220 | |
| 221 | MODULE_AUTHOR("Aeroflex Gaisler AB."); |
| 222 | MODULE_DESCRIPTION("GRLIB APBPS2 PS/2 serial I/O"); |
| 223 | MODULE_LICENSE("GPL"); |