pci/bt8xx/bttv-i2c.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003
0004     bttv-i2c.c  --  all the i2c code is here
0005
0006     bttv - Bt848 frame grabber driver
0007
0008     Copyright (C) 1996,97,98 Ralph  Metzler (rjkm@thp.uni-koeln.de)
0009                & Marcus Metzler (mocm@thp.uni-koeln.de)
0010     (c) 1999-2003 Gerd Knorr <kraxel@bytesex.org>
0011
0012     (c) 2005 Mauro Carvalho Chehab <mchehab@kernel.org>
0013     - Multituner support and i2c address binding
0014
0015
0016 */
0017
0018 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0019
0020 #include <linux/module.h>
0021 #include <linux/init.h>
0022 #include <linux/delay.h>
0023
0024 #include "bttvp.h"
0025 #include <media/v4l2-common.h>
0026 #include <linux/jiffies.h>
0027 #include <asm/io.h>
0028
0029 static int i2c_debug;
0030 static int i2c_hw;
0031 static int i2c_scan;
0032 module_param(i2c_debug, int, 0644);
0033 MODULE_PARM_DESC(i2c_debug, "configure i2c debug level");
0034 module_param(i2c_hw,    int, 0444);
0035 MODULE_PARM_DESC(i2c_hw, "force use of hardware i2c support, instead of software bitbang");
0036 module_param(i2c_scan,  int, 0444);
0037 MODULE_PARM_DESC(i2c_scan,"scan i2c bus at insmod time");
0038
0039 static unsigned int i2c_udelay = 5;
0040 module_param(i2c_udelay, int, 0444);
0041 MODULE_PARM_DESC(i2c_udelay, "soft i2c delay at insmod time, in usecs (should be 5 or higher). Lower value means higher bus speed.");
0042
0043 /* ----------------------------------------------------------------------- */
0044 /* I2C functions - bitbanging adapter (software i2c)                       */
0045
0046 static void bttv_bit_setscl(void *data, int state)
0047 {
0048     struct bttv *btv = (struct bttv*)data;
0049
0050     if (state)
0051         btv->i2c_state |= 0x02;
0052     else
0053         btv->i2c_state &= ~0x02;
0054     btwrite(btv->i2c_state, BT848_I2C);
0055     btread(BT848_I2C);
0056 }
0057
0058 static void bttv_bit_setsda(void *data, int state)
0059 {
0060     struct bttv *btv = (struct bttv*)data;
0061
0062     if (state)
0063         btv->i2c_state |= 0x01;
0064     else
0065         btv->i2c_state &= ~0x01;
0066     btwrite(btv->i2c_state, BT848_I2C);
0067     btread(BT848_I2C);
0068 }
0069
0070 static int bttv_bit_getscl(void *data)
0071 {
0072     struct bttv *btv = (struct bttv*)data;
0073     int state;
0074
0075     state = btread(BT848_I2C) & 0x02 ? 1 : 0;
0076     return state;
0077 }
0078
0079 static int bttv_bit_getsda(void *data)
0080 {
0081     struct bttv *btv = (struct bttv*)data;
0082     int state;
0083
0084     state = btread(BT848_I2C) & 0x01;
0085     return state;
0086 }
0087
0088 static const struct i2c_algo_bit_data bttv_i2c_algo_bit_template = {
0089     .setsda  = bttv_bit_setsda,
0090     .setscl  = bttv_bit_setscl,
0091     .getsda  = bttv_bit_getsda,
0092     .getscl  = bttv_bit_getscl,
0093     .udelay  = 16,
0094     .timeout = 200,
0095 };
0096
0097 /* ----------------------------------------------------------------------- */
0098 /* I2C functions - hardware i2c                                            */
0099
0100 static u32 functionality(struct i2c_adapter *adap)
0101 {
0102     return I2C_FUNC_SMBUS_EMUL;
0103 }
0104
0105 static int
0106 bttv_i2c_wait_done(struct bttv *btv)
0107 {
0108     int rc = 0;
0109
0110     /* timeout */
0111     if (wait_event_interruptible_timeout(btv->i2c_queue,
0112         btv->i2c_done, msecs_to_jiffies(85)) == -ERESTARTSYS)
0113         rc = -EIO;
0114
0115     if (btv->i2c_done & BT848_INT_RACK)
0116         rc = 1;
0117     btv->i2c_done = 0;
0118     return rc;
0119 }
0120
0121 #define I2C_HW (BT878_I2C_MODE  | BT848_I2C_SYNC |\
0122         BT848_I2C_SCL | BT848_I2C_SDA)
0123
0124 static int
0125 bttv_i2c_sendbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
0126 {
0127     u32 xmit;
0128     int retval,cnt;
0129
0130     /* sanity checks */
0131     if (0 == msg->len)
0132         return -EINVAL;
0133
0134     /* start, address + first byte */
0135     xmit = (msg->addr << 25) | (msg->buf[0] << 16) | I2C_HW;
0136     if (msg->len > 1 || !last)
0137         xmit |= BT878_I2C_NOSTOP;
0138     btwrite(xmit, BT848_I2C);
0139     retval = bttv_i2c_wait_done(btv);
0140     if (retval < 0)
0141         goto err;
0142     if (retval == 0)
0143         goto eio;
0144     if (i2c_debug) {
0145         pr_cont(" <W %02x %02x", msg->addr << 1, msg->buf[0]);
0146     }
0147
0148     for (cnt = 1; cnt < msg->len; cnt++ ) {
0149         /* following bytes */
0150         xmit = (msg->buf[cnt] << 24) | I2C_HW | BT878_I2C_NOSTART;
0151         if (cnt < msg->len-1 || !last)
0152             xmit |= BT878_I2C_NOSTOP;
0153         btwrite(xmit, BT848_I2C);
0154         retval = bttv_i2c_wait_done(btv);
0155         if (retval < 0)
0156             goto err;
0157         if (retval == 0)
0158             goto eio;
0159         if (i2c_debug)
0160             pr_cont(" %02x", msg->buf[cnt]);
0161     }
0162     if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
0163         pr_cont(">\n");
0164     return msg->len;
0165
0166  eio:
0167     retval = -EIO;
0168  err:
0169     if (i2c_debug)
0170         pr_cont(" ERR: %d\n",retval);
0171     return retval;
0172 }
0173
0174 static int
0175 bttv_i2c_readbytes(struct bttv *btv, const struct i2c_msg *msg, int last)
0176 {
0177     u32 xmit;
0178     u32 cnt;
0179     int retval;
0180
0181     for (cnt = 0; cnt < msg->len; cnt++) {
0182         xmit = (msg->addr << 25) | (1 << 24) | I2C_HW;
0183         if (cnt < msg->len-1)
0184             xmit |= BT848_I2C_W3B;
0185         if (cnt < msg->len-1 || !last)
0186             xmit |= BT878_I2C_NOSTOP;
0187         if (cnt)
0188             xmit |= BT878_I2C_NOSTART;
0189
0190         if (i2c_debug) {
0191             if (!(xmit & BT878_I2C_NOSTART))
0192                 pr_cont(" <R %02x", (msg->addr << 1) +1);
0193         }
0194
0195         btwrite(xmit, BT848_I2C);
0196         retval = bttv_i2c_wait_done(btv);
0197         if (retval < 0)
0198             goto err;
0199         if (retval == 0)
0200             goto eio;
0201         msg->buf[cnt] = ((u32)btread(BT848_I2C) >> 8) & 0xff;
0202         if (i2c_debug) {
0203             pr_cont(" =%02x", msg->buf[cnt]);
0204         }
0205         if (i2c_debug && !(xmit & BT878_I2C_NOSTOP))
0206             pr_cont(" >\n");
0207     }
0208
0209
0210     return msg->len;
0211
0212  eio:
0213     retval = -EIO;
0214  err:
0215     if (i2c_debug)
0216         pr_cont(" ERR: %d\n",retval);
0217     return retval;
0218 }
0219
0220 static int bttv_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
0221 {
0222     struct v4l2_device *v4l2_dev = i2c_get_adapdata(i2c_adap);
0223     struct bttv *btv = to_bttv(v4l2_dev);
0224     int retval = 0;
0225     int i;
0226
0227     if (i2c_debug)
0228         pr_debug("bt-i2c:");
0229
0230     btwrite(BT848_INT_I2CDONE|BT848_INT_RACK, BT848_INT_STAT);
0231     for (i = 0 ; i < num; i++) {
0232         if (msgs[i].flags & I2C_M_RD) {
0233             /* read */
0234             retval = bttv_i2c_readbytes(btv, &msgs[i], i+1 == num);
0235             if (retval < 0)
0236                 goto err;
0237         } else {
0238             /* write */
0239             retval = bttv_i2c_sendbytes(btv, &msgs[i], i+1 == num);
0240             if (retval < 0)
0241                 goto err;
0242         }
0243     }
0244     return num;
0245
0246  err:
0247     return retval;
0248 }
0249
0250 static const struct i2c_algorithm bttv_algo = {
0251     .master_xfer   = bttv_i2c_xfer,
0252     .functionality = functionality,
0253 };
0254
0255 /* ----------------------------------------------------------------------- */
0256 /* I2C functions - common stuff                                            */
0257
0258 /* read I2C */
0259 int bttv_I2CRead(struct bttv *btv, unsigned char addr, char *probe_for)
0260 {
0261     unsigned char buffer = 0;
0262
0263     if (0 != btv->i2c_rc)
0264         return -1;
0265     if (bttv_verbose && NULL != probe_for)
0266         pr_info("%d: i2c: checking for %s @ 0x%02x... ",
0267             btv->c.nr, probe_for, addr);
0268     btv->i2c_client.addr = addr >> 1;
0269     if (1 != i2c_master_recv(&btv->i2c_client, &buffer, 1)) {
0270         if (NULL != probe_for) {
0271             if (bttv_verbose)
0272                 pr_cont("not found\n");
0273         } else
0274             pr_warn("%d: i2c read 0x%x: error\n",
0275                 btv->c.nr, addr);
0276         return -1;
0277     }
0278     if (bttv_verbose && NULL != probe_for)
0279         pr_cont("found\n");
0280     return buffer;
0281 }
0282
0283 /* write I2C */
0284 int bttv_I2CWrite(struct bttv *btv, unsigned char addr, unsigned char b1,
0285             unsigned char b2, int both)
0286 {
0287     unsigned char buffer[2];
0288     int bytes = both ? 2 : 1;
0289
0290     if (0 != btv->i2c_rc)
0291         return -1;
0292     btv->i2c_client.addr = addr >> 1;
0293     buffer[0] = b1;
0294     buffer[1] = b2;
0295     if (bytes != i2c_master_send(&btv->i2c_client, buffer, bytes))
0296         return -1;
0297     return 0;
0298 }
0299
0300 /* read EEPROM content */
0301 void bttv_readee(struct bttv *btv, unsigned char *eedata, int addr)
0302 {
0303     memset(eedata, 0, 256);
0304     if (0 != btv->i2c_rc)
0305         return;
0306     btv->i2c_client.addr = addr >> 1;
0307     tveeprom_read(&btv->i2c_client, eedata, 256);
0308 }
0309
0310 static char *i2c_devs[128] = {
0311     [ 0x1c >> 1 ] = "lgdt330x",
0312     [ 0x30 >> 1 ] = "IR (hauppauge)",
0313     [ 0x80 >> 1 ] = "msp34xx",
0314     [ 0x86 >> 1 ] = "tda9887",
0315     [ 0xa0 >> 1 ] = "eeprom",
0316     [ 0xc0 >> 1 ] = "tuner (analog)",
0317     [ 0xc2 >> 1 ] = "tuner (analog)",
0318 };
0319
0320 static void do_i2c_scan(char *name, struct i2c_client *c)
0321 {
0322     unsigned char buf;
0323     int i,rc;
0324
0325     for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
0326         c->addr = i;
0327         rc = i2c_master_recv(c,&buf,0);
0328         if (rc < 0)
0329             continue;
0330         pr_info("%s: i2c scan: found device @ 0x%x  [%s]\n",
0331             name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
0332     }
0333 }
0334
0335 /* init + register i2c adapter */
0336 int init_bttv_i2c(struct bttv *btv)
0337 {
0338     strscpy(btv->i2c_client.name, "bttv internal", I2C_NAME_SIZE);
0339
0340     if (i2c_hw)
0341         btv->use_i2c_hw = 1;
0342     if (btv->use_i2c_hw) {
0343         /* bt878 */
0344         strscpy(btv->c.i2c_adap.name, "bt878",
0345             sizeof(btv->c.i2c_adap.name));
0346         btv->c.i2c_adap.algo = &bttv_algo;
0347     } else {
0348         /* bt848 */
0349     /* Prevents usage of invalid delay values */
0350         if (i2c_udelay<5)
0351             i2c_udelay=5;
0352
0353         strscpy(btv->c.i2c_adap.name, "bttv",
0354             sizeof(btv->c.i2c_adap.name));
0355         btv->i2c_algo = bttv_i2c_algo_bit_template;
0356         btv->i2c_algo.udelay = i2c_udelay;
0357         btv->i2c_algo.data = btv;
0358         btv->c.i2c_adap.algo_data = &btv->i2c_algo;
0359     }
0360     btv->c.i2c_adap.owner = THIS_MODULE;
0361
0362     btv->c.i2c_adap.dev.parent = &btv->c.pci->dev;
0363     snprintf(btv->c.i2c_adap.name, sizeof(btv->c.i2c_adap.name),
0364          "bt%d #%d [%s]", btv->id, btv->c.nr,
0365          btv->use_i2c_hw ? "hw" : "sw");
0366
0367     i2c_set_adapdata(&btv->c.i2c_adap, &btv->c.v4l2_dev);
0368     btv->i2c_client.adapter = &btv->c.i2c_adap;
0369
0370
0371     if (btv->use_i2c_hw) {
0372         btv->i2c_rc = i2c_add_adapter(&btv->c.i2c_adap);
0373     } else {
0374         bttv_bit_setscl(btv,1);
0375         bttv_bit_setsda(btv,1);
0376         btv->i2c_rc = i2c_bit_add_bus(&btv->c.i2c_adap);
0377     }
0378     if (0 == btv->i2c_rc && i2c_scan)
0379         do_i2c_scan(btv->c.v4l2_dev.name, &btv->i2c_client);
0380
0381     return btv->i2c_rc;
0382 }
0383
0384 int fini_bttv_i2c(struct bttv *btv)
0385 {
0386     if (btv->i2c_rc == 0)
0387         i2c_del_adapter(&btv->c.i2c_adap);
0388
0389     return 0;
0390 }