net: mdio: Clarify code flow Covarity 244085 & 244090
[platform/kernel/u-boot.git] / cmd / mdio.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2011 Freescale Semiconductor, Inc
4  * Andy Fleming
5  */
6
7 /*
8  * MDIO Commands
9  */
10
11 #include <common.h>
12 #include <command.h>
13 #include <miiphy.h>
14 #include <phy.h>
15
16 static char last_op[2];
17 static uint last_data;
18 static uint last_addr_lo;
19 static uint last_addr_hi;
20 static uint last_devad_lo;
21 static uint last_devad_hi;
22 static uint last_reg_lo;
23 static uint last_reg_hi;
24
25 static int extract_range(char *input, int *plo, int *phi)
26 {
27         char *end;
28         *plo = simple_strtol(input, &end, 16);
29         if (end == input)
30                 return -1;
31
32         if ((*end == '-') && *(++end))
33                 *phi = simple_strtol(end, NULL, 16);
34         else if (*end == '\0')
35                 *phi = *plo;
36         else
37                 return -1;
38
39         return 0;
40 }
41
42 static int mdio_write_ranges(struct mii_dev *bus,
43                              int addrlo,
44                              int addrhi, int devadlo, int devadhi,
45                              int reglo, int reghi, unsigned short data,
46                              int extended)
47 {
48         struct phy_device *phydev;
49         int addr, devad, reg;
50         int err = 0;
51
52         for (addr = addrlo; addr <= addrhi; addr++) {
53                 phydev = bus->phymap[addr];
54
55                 for (devad = devadlo; devad <= devadhi; devad++) {
56                         for (reg = reglo; reg <= reghi; reg++) {
57                                 if (!phydev)
58                                         err = bus->write(bus, addr, devad,
59                                                          reg, data);
60                                 else if (!extended)
61                                         err = phy_write_mmd(phydev, devad,
62                                                             reg, data);
63                                 else
64                                         err = phydev->drv->writeext(phydev,
65                                                         addr, devad, reg, data);
66
67                                 if (err)
68                                         goto err_out;
69                         }
70                 }
71         }
72
73 err_out:
74         return err;
75 }
76
77 static int mdio_read_ranges(struct mii_dev *bus,
78                             int addrlo,
79                             int addrhi, int devadlo, int devadhi,
80                             int reglo, int reghi, int extended)
81 {
82         int addr, devad, reg;
83         struct phy_device *phydev;
84
85         printf("Reading from bus %s\n", bus->name);
86         for (addr = addrlo; addr <= addrhi; addr++) {
87                 phydev = bus->phymap[addr];
88                 printf("PHY at address %x:\n", addr);
89
90                 for (devad = devadlo; devad <= devadhi; devad++) {
91                         for (reg = reglo; reg <= reghi; reg++) {
92                                 int val;
93
94                                 if (!phydev)
95                                         val = bus->read(bus, addr, devad, reg);
96                                 else if (!extended)
97                                         val = phy_read_mmd(phydev, devad, reg);
98                                 else
99                                         val = phydev->drv->readext(phydev, addr,
100                                                 devad, reg);
101
102                                 if (val < 0) {
103                                         printf("Error\n");
104
105                                         return val;
106                                 }
107
108                                 if (devad >= 0)
109                                         printf("%d.", devad);
110
111                                 printf("%d - 0x%x\n", reg, val & 0xffff);
112                         }
113                 }
114         }
115
116         return 0;
117 }
118
119 /* The register will be in the form [a[-b].]x[-y] */
120 static int extract_reg_range(char *input, int *devadlo, int *devadhi,
121                              int *reglo, int *reghi)
122 {
123         char *regstr;
124
125         /* use strrchr to find the last string after a '.' */
126         regstr = strrchr(input, '.');
127
128         /* If it exists, extract the devad(s) */
129         if (regstr) {
130                 char devadstr[32];
131
132                 strncpy(devadstr, input, regstr - input);
133                 devadstr[regstr - input] = '\0';
134
135                 if (extract_range(devadstr, devadlo, devadhi))
136                         return -1;
137
138                 regstr++;
139         } else {
140                 /* Otherwise, we have no devad, and we just got regs */
141                 *devadlo = *devadhi = MDIO_DEVAD_NONE;
142
143                 regstr = input;
144         }
145
146         return extract_range(regstr, reglo, reghi);
147 }
148
149 static int extract_phy_range(char *const argv[], int argc, struct mii_dev **bus,
150                              struct phy_device **phydev,
151                              int *addrlo, int *addrhi)
152 {
153         struct phy_device *dev = *phydev;
154
155         if ((argc < 1) || (argc > 2))
156                 return -1;
157
158         /* If there are two arguments, it's busname addr */
159         if (argc == 2) {
160                 *bus = miiphy_get_dev_by_name(argv[0]);
161
162                 if (!*bus)
163                         return -1;
164
165                 return extract_range(argv[1], addrlo, addrhi);
166         }
167
168         /* It must be one argument, here */
169
170         /*
171          * This argument can be one of two things:
172          * 1) Ethernet device name
173          * 2) Just an address (use the previously-used bus)
174          *
175          * We check all buses for a PHY which is connected to an ethernet
176          * device by the given name.  If none are found, we call
177          * extract_range() on the string, and see if it's an address range.
178          */
179         dev = mdio_phydev_for_ethname(argv[0]);
180
181         if (dev) {
182                 *addrlo = *addrhi = dev->addr;
183                 *bus = dev->bus;
184
185                 return 0;
186         }
187
188         /* It's an address or nothing useful */
189         return extract_range(argv[0], addrlo, addrhi);
190 }
191
192 /* ---------------------------------------------------------------- */
193 static int do_mdio(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
194 {
195         char op[2];
196         int addrlo, addrhi, reglo, reghi, devadlo, devadhi;
197         unsigned short  data;
198         int pos = argc - 1;
199         struct mii_dev *bus;
200         struct phy_device *phydev = NULL;
201         int extended = 0;
202
203         if (argc < 2)
204                 return CMD_RET_USAGE;
205
206 #ifdef CONFIG_DM_MDIO
207         /* probe DM MII device before any operation so they are all accesible */
208         dm_mdio_probe_devices();
209 #endif
210
211         /*
212          * We use the last specified parameters, unless new ones are
213          * entered.
214          */
215         op[0] = argv[1][0];
216         addrlo = last_addr_lo;
217         addrhi = last_addr_hi;
218         devadlo = last_devad_lo;
219         devadhi = last_devad_hi;
220         reglo  = last_reg_lo;
221         reghi  = last_reg_hi;
222         data   = last_data;
223
224         bus = mdio_get_current_dev();
225
226         if (flag & CMD_FLAG_REPEAT)
227                 op[0] = last_op[0];
228
229         if (strlen(argv[1]) > 1) {
230                 op[1] = argv[1][1];
231                 if (op[1] == 'x') {
232                         phydev = mdio_phydev_for_ethname(argv[2]);
233
234                         if (phydev) {
235                                 addrlo = phydev->addr;
236                                 addrhi = addrlo;
237                                 bus = phydev->bus;
238                                 extended = 1;
239                         } else {
240                                 return CMD_RET_FAILURE;
241                         }
242
243                         if (!phydev->drv ||
244                             (!phydev->drv->writeext && (op[0] == 'w')) ||
245                             (!phydev->drv->readext && (op[0] == 'r'))) {
246                                 puts("PHY does not have extended functions\n");
247                                 return CMD_RET_FAILURE;
248                         }
249                 }
250         }
251
252         switch (op[0]) {
253         case 'w':
254                 if (pos > 1)
255                         data = simple_strtoul(argv[pos--], NULL, 16);
256                 /* Intentional fall-through - Get reg for read and write */
257         case 'r':
258                 if (pos > 1)
259                         if (extract_reg_range(argv[pos--], &devadlo, &devadhi,
260                                               &reglo, &reghi))
261                                 return CMD_RET_FAILURE;
262                 /* Intentional fall-through - Get phy for all commands */
263         default:
264                 if (pos > 1)
265                         if (extract_phy_range(&argv[2], pos - 1, &bus,
266                                               &phydev, &addrlo, &addrhi))
267                                 return CMD_RET_FAILURE;
268
269                 break;
270         }
271
272         if (!bus) {
273                 puts("No MDIO bus found\n");
274                 return CMD_RET_FAILURE;
275         }
276
277         if (op[0] == 'l') {
278                 mdio_list_devices();
279
280                 return 0;
281         }
282
283         /* Save the chosen bus */
284         miiphy_set_current_dev(bus->name);
285
286         switch (op[0]) {
287         case 'w':
288                 mdio_write_ranges(bus, addrlo, addrhi, devadlo, devadhi,
289                                   reglo, reghi, data, extended);
290                 break;
291
292         case 'r':
293                 mdio_read_ranges(bus, addrlo, addrhi, devadlo, devadhi,
294                                  reglo, reghi, extended);
295                 break;
296         }
297
298         /*
299          * Save the parameters for repeats.
300          */
301         last_op[0] = op[0];
302         last_addr_lo = addrlo;
303         last_addr_hi = addrhi;
304         last_devad_lo = devadlo;
305         last_devad_hi = devadhi;
306         last_reg_lo  = reglo;
307         last_reg_hi  = reghi;
308         last_data    = data;
309
310         return 0;
311 }
312
313 /***************************************************/
314
315 U_BOOT_CMD(
316         mdio,   6,      1,      do_mdio,
317         "MDIO utility commands",
318         "list                   - List MDIO buses\n"
319         "mdio read <phydev> [<devad>.]<reg> - "
320                 "read PHY's register at <devad>.<reg>\n"
321         "mdio write <phydev> [<devad>.]<reg> <data> - "
322                 "write PHY's register at <devad>.<reg>\n"
323         "mdio rx <phydev> [<devad>.]<reg> - "
324                 "read PHY's extended register at <devad>.<reg>\n"
325         "mdio wx <phydev> [<devad>.]<reg> <data> - "
326                 "write PHY's extended register at <devad>.<reg>\n"
327         "<phydev> may be:\n"
328         "   <busname>  <addr>\n"
329         "   <addr>\n"
330         "   <eth name>\n"
331         "<addr> <devad>, and <reg> may be ranges, e.g. 1-5.4-0x1f.\n"
332 );