Sylvain Munaut | 70c10f0 | 2022-01-12 11:58:34 +0100 | [diff] [blame^] | 1 | /* |
| 2 | * usb_gps.c |
| 3 | * |
| 4 | * Copyright (C) 2019-2022 Sylvain Munaut <tnt@246tNt.com> |
| 5 | * SPDX-License-Identifier: GPL-3.0-or-later |
| 6 | */ |
| 7 | |
| 8 | #include <stdint.h> |
| 9 | #include <stdbool.h> |
| 10 | #include <string.h> |
| 11 | |
| 12 | #include <no2usb/usb.h> |
| 13 | #include <no2usb/usb_hw.h> |
| 14 | #include <no2usb/usb_priv.h> |
| 15 | |
| 16 | #include <no2usb/usb_proto.h> |
| 17 | #include <no2usb/usb_cdc_proto.h> |
| 18 | |
| 19 | #include "console.h" |
| 20 | #include "usb_desc_ids.h" |
| 21 | |
| 22 | |
| 23 | #define BUF_SIZE_LOG 9 |
| 24 | #define BUF_SIZE (1 << BUF_SIZE_LOG) |
| 25 | #define BUF_MASK (BUF_SIZE - 1) |
| 26 | |
| 27 | static struct { |
| 28 | /* State */ |
| 29 | bool active; |
| 30 | |
| 31 | /* Buffer */ |
| 32 | struct { |
| 33 | unsigned int wr; |
| 34 | unsigned int rd; |
| 35 | char data[BUF_SIZE] __attribute__((aligned(4))); |
| 36 | } buf; |
| 37 | } g_usb_gps; |
| 38 | |
| 39 | |
| 40 | static void |
| 41 | _usb_gps_set_active(bool active) |
| 42 | { |
| 43 | /* Save new state */ |
| 44 | g_usb_gps.active = active; |
| 45 | |
| 46 | /* Reset FIFO if disabled */ |
| 47 | if (!active) |
| 48 | g_usb_gps.buf.wr = g_usb_gps.buf.rd = 0; |
| 49 | } |
| 50 | |
| 51 | static int |
| 52 | _usb_gps_fill_packet(unsigned int dst_ofs) |
| 53 | { |
| 54 | unsigned int len; |
| 55 | |
| 56 | /* Len available, limited to 64 */ |
| 57 | len = (g_usb_gps.buf.wr - g_usb_gps.buf.rd) & BUF_MASK; |
| 58 | |
| 59 | if (len > 64) |
| 60 | len = 64; |
| 61 | |
| 62 | /* Copy block */ |
| 63 | usb_data_write(dst_ofs, &g_usb_gps.buf.data[g_usb_gps.buf.rd], (len + 3) & ~3); |
| 64 | |
| 65 | /* Increment read pointer */ |
| 66 | g_usb_gps.buf.rd = (g_usb_gps.buf.rd + len) & BUF_MASK; |
| 67 | |
| 68 | /* If length was not multiple of 4, we emptied the FIFO, |
| 69 | * so we reset it to 0 so we're aligned again */ |
| 70 | if (len & 3) |
| 71 | g_usb_gps.buf.wr = g_usb_gps.buf.rd = 0; |
| 72 | |
| 73 | return len; |
| 74 | } |
| 75 | |
| 76 | |
| 77 | void |
| 78 | usb_gps_puts(const char *str) |
| 79 | { |
| 80 | unsigned int nxt; |
| 81 | char c; |
| 82 | |
| 83 | if (!g_usb_gps.active) |
| 84 | return; |
| 85 | |
| 86 | while ((c = *str++) != '\0') |
| 87 | { |
| 88 | /* Next write pointer pos and full check */ |
| 89 | nxt = (g_usb_gps.buf.wr + 1) & BUF_MASK; |
| 90 | if (nxt == g_usb_gps.buf.rd) |
| 91 | /* If overflow, we keep the latest content ... */ |
| 92 | g_usb_gps.buf.rd = (g_usb_gps.buf.rd + 1) & BUF_MASK; |
| 93 | |
| 94 | /* Write data */ |
| 95 | g_usb_gps.buf.data[g_usb_gps.buf.wr] = c; |
| 96 | |
| 97 | /* Update write pointer */ |
| 98 | g_usb_gps.buf.wr = nxt; |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | void |
| 103 | usb_gps_poll(void) |
| 104 | { |
| 105 | volatile struct usb_ep *ep_regs; |
| 106 | |
| 107 | /* OUT EP: We accept data and throw it away */ |
| 108 | ep_regs = &usb_ep_regs[USB_EP_GPS_CDC_OUT & 0x1f].out; |
| 109 | ep_regs->bd[0].csr = USB_BD_STATE_RDY_DATA | USB_BD_LEN(64); |
| 110 | |
| 111 | /* IN EP: Send whatever is queued */ |
| 112 | ep_regs = &usb_ep_regs[USB_EP_GPS_CDC_OUT & 0x1f].in; |
| 113 | |
| 114 | if ((ep_regs->bd[0].csr & USB_BD_STATE_MSK) != USB_BD_STATE_RDY_DATA) |
| 115 | { |
| 116 | int len = _usb_gps_fill_packet(ep_regs->bd[0].ptr); |
| 117 | |
| 118 | if (len) |
| 119 | ep_regs->bd[0].csr = USB_BD_STATE_RDY_DATA | USB_BD_LEN(len); |
| 120 | else |
| 121 | ep_regs->bd[0].csr = 0; |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | |
| 126 | static enum usb_fnd_resp |
| 127 | _cdc_set_conf(const struct usb_conf_desc *conf) |
| 128 | { |
| 129 | const struct usb_intf_desc *intf; |
| 130 | |
| 131 | if (!conf) |
| 132 | return USB_FND_SUCCESS; |
| 133 | |
| 134 | /* Configure control interface */ |
| 135 | intf = usb_desc_find_intf(conf, USB_INTF_GPS_CDC_CTL, 0, NULL); |
| 136 | if (!intf) |
| 137 | return USB_FND_ERROR; |
| 138 | |
| 139 | usb_ep_boot(intf, USB_EP_GPS_CDC_CTL, false); |
| 140 | |
| 141 | /* Configure data interface */ |
| 142 | intf = usb_desc_find_intf(conf, USB_INTF_GPS_CDC_DATA, 0, NULL); |
| 143 | if (!intf) |
| 144 | return USB_FND_ERROR; |
| 145 | |
| 146 | usb_ep_boot(intf, USB_EP_GPS_CDC_OUT, false); |
| 147 | usb_ep_boot(intf, USB_EP_GPS_CDC_IN, false); |
| 148 | |
| 149 | return USB_FND_SUCCESS; |
| 150 | } |
| 151 | |
| 152 | static enum usb_fnd_resp |
| 153 | _cdc_ctrl_req(struct usb_ctrl_req *req, struct usb_xfer *xfer) |
| 154 | { |
| 155 | static const struct usb_cdc_line_coding linecoding = { |
| 156 | .dwDTERate = 115200, |
| 157 | .bCharFormat = 2, |
| 158 | .bParityType = 0, |
| 159 | .bDataBits = 8, |
| 160 | }; |
| 161 | |
| 162 | /* Check this is handled here */ |
| 163 | if (USB_REQ_TYPE_RCPT(req) != (USB_REQ_TYPE_CLASS | USB_REQ_RCPT_INTF)) |
| 164 | return USB_FND_CONTINUE; |
| 165 | |
| 166 | if (req->wIndex != USB_INTF_GPS_CDC_CTL) |
| 167 | return USB_FND_CONTINUE; |
| 168 | |
| 169 | /* Process request */ |
| 170 | switch (req->bRequest) { |
| 171 | case USB_REQ_CDC_SEND_ENCAPSULATED_COMMAND: |
| 172 | /* We don't support any, so just accept and don't care */ |
| 173 | return USB_FND_SUCCESS; |
| 174 | |
| 175 | case USB_REQ_CDC_GET_ENCAPSULATED_RESPONSE: |
| 176 | /* Never anything to return */ |
| 177 | xfer->len = 0; |
| 178 | return USB_FND_SUCCESS; |
| 179 | |
| 180 | case USB_REQ_CDC_SET_LINE_CODING: |
| 181 | /* We only support 1 config, doesn't matter what the hosts sends */ |
| 182 | return USB_FND_SUCCESS; |
| 183 | |
| 184 | case USB_REQ_CDC_GET_LINE_CODING: |
| 185 | /* We only support 1 config, send that back */ |
| 186 | xfer->data = (void*)&linecoding; |
| 187 | xfer->len = sizeof(linecoding); |
| 188 | return USB_FND_ERROR; |
| 189 | |
| 190 | case USB_REQ_CDC_SET_CONTROL_LINE_STATE: |
| 191 | /* Enable if DTR is set */ |
| 192 | _usb_gps_set_active((req->wValue & 1) != 0); |
| 193 | return USB_FND_SUCCESS; |
| 194 | } |
| 195 | |
| 196 | /* Anything else is not handled */ |
| 197 | return USB_FND_ERROR; |
| 198 | } |
| 199 | |
| 200 | |
| 201 | static struct usb_fn_drv _cdc_drv = { |
| 202 | .set_conf = _cdc_set_conf, |
| 203 | .ctrl_req = _cdc_ctrl_req, |
| 204 | }; |
| 205 | |
| 206 | void |
| 207 | usb_gps_init(void) |
| 208 | { |
| 209 | memset(&g_usb_gps, 0x00, sizeof(g_usb_gps)); |
| 210 | usb_register_function_driver(&_cdc_drv); |
| 211 | } |