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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 | // SPDX-License-Identifier: GPL-2.0-only /* * Amstrad E3 (Delta) keyboard port driver * * Copyright (c) 2006 Matt Callow * Copyright (c) 2010 Janusz Krzysztofik * * Thanks to Cliff Lawson for his help * * The Amstrad Delta keyboard (aka mailboard) uses normal PC-AT style serial * transmission. The keyboard port is formed of two GPIO lines, for clock * and data. Due to strict timing requirements of the interface, * the serial data stream is read and processed by a FIQ handler. * The resulting words are fetched by this driver from a circular buffer. * * Standard AT keyboard driver (atkbd) is used for handling the keyboard data. * However, when used with the E3 mailboard that producecs non-standard * scancodes, a custom key table must be prepared and loaded from userspace. */ #include <linux/irq.h> #include <linux/platform_data/ams-delta-fiq.h> #include <linux/platform_device.h> #include <linux/regulator/consumer.h> #include <linux/serio.h> #include <linux/slab.h> #include <linux/module.h> #define DRIVER_NAME "ams-delta-serio" MODULE_AUTHOR("Matt Callow"); MODULE_DESCRIPTION("AMS Delta (E3) keyboard port driver"); MODULE_LICENSE("GPL"); struct ams_delta_serio { struct serio *serio; struct regulator *vcc; unsigned int *fiq_buffer; }; static int check_data(struct serio *serio, int data) { int i, parity = 0; /* check valid stop bit */ if (!(data & 0x400)) { dev_warn(&serio->dev, "invalid stop bit, data=0x%X\n", data); return SERIO_FRAME; } /* calculate the parity */ for (i = 1; i < 10; i++) { if (data & (1 << i)) parity++; } /* it should be odd */ if (!(parity & 0x01)) { dev_warn(&serio->dev, "parity check failed, data=0x%X parity=0x%X\n", data, parity); return SERIO_PARITY; } return 0; } static irqreturn_t ams_delta_serio_interrupt(int irq, void *dev_id) { struct ams_delta_serio *priv = dev_id; int *circ_buff = &priv->fiq_buffer[FIQ_CIRC_BUFF]; int data, dfl; u8 scancode; priv->fiq_buffer[FIQ_IRQ_PEND] = 0; /* * Read data from the circular buffer, check it * and then pass it on the serio */ while (priv->fiq_buffer[FIQ_KEYS_CNT] > 0) { data = circ_buff[priv->fiq_buffer[FIQ_HEAD_OFFSET]++]; priv->fiq_buffer[FIQ_KEYS_CNT]--; if (priv->fiq_buffer[FIQ_HEAD_OFFSET] == priv->fiq_buffer[FIQ_BUF_LEN]) priv->fiq_buffer[FIQ_HEAD_OFFSET] = 0; dfl = check_data(priv->serio, data); scancode = (u8) (data >> 1) & 0xFF; serio_interrupt(priv->serio, scancode, dfl); } return IRQ_HANDLED; } static int ams_delta_serio_open(struct serio *serio) { struct ams_delta_serio *priv = serio->port_data; /* enable keyboard */ return regulator_enable(priv->vcc); } static void ams_delta_serio_close(struct serio *serio) { struct ams_delta_serio *priv = serio->port_data; /* disable keyboard */ regulator_disable(priv->vcc); } static int ams_delta_serio_init(struct platform_device *pdev) { struct ams_delta_serio *priv; struct serio *serio; int irq, err; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; priv->fiq_buffer = pdev->dev.platform_data; if (!priv->fiq_buffer) return -EINVAL; priv->vcc = devm_regulator_get(&pdev->dev, "vcc"); if (IS_ERR(priv->vcc)) { err = PTR_ERR(priv->vcc); dev_err(&pdev->dev, "regulator request failed (%d)\n", err); /* * When running on a non-dt platform and requested regulator * is not available, devm_regulator_get() never returns * -EPROBE_DEFER as it is not able to justify if the regulator * may still appear later. On the other hand, the board can * still set full constriants flag at late_initcall in order * to instruct devm_regulator_get() to returnn a dummy one * if sufficient. Hence, if we get -ENODEV here, let's convert * it to -EPROBE_DEFER and wait for the board to decide or * let Deferred Probe infrastructure handle this error. */ if (err == -ENODEV) err = -EPROBE_DEFER; return err; } irq = platform_get_irq(pdev, 0); if (irq < 0) return -ENXIO; err = devm_request_irq(&pdev->dev, irq, ams_delta_serio_interrupt, IRQ_TYPE_EDGE_RISING, DRIVER_NAME, priv); if (err < 0) { dev_err(&pdev->dev, "IRQ request failed (%d)\n", err); return err; } serio = kzalloc(sizeof(*serio), GFP_KERNEL); if (!serio) return -ENOMEM; priv->serio = serio; serio->id.type = SERIO_8042; serio->open = ams_delta_serio_open; serio->close = ams_delta_serio_close; strscpy(serio->name, "AMS DELTA keyboard adapter", sizeof(serio->name)); strscpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys)); serio->dev.parent = &pdev->dev; serio->port_data = priv; serio_register_port(serio); platform_set_drvdata(pdev, priv); dev_info(&serio->dev, "%s\n", serio->name); return 0; } static int ams_delta_serio_exit(struct platform_device *pdev) { struct ams_delta_serio *priv = platform_get_drvdata(pdev); serio_unregister_port(priv->serio); return 0; } static struct platform_driver ams_delta_serio_driver = { .probe = ams_delta_serio_init, .remove = ams_delta_serio_exit, .driver = { .name = DRIVER_NAME }, }; module_platform_driver(ams_delta_serio_driver); |