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Diffstat (limited to 'drivers/media/usb/em28xx/em28xx-i2c.c')
-rw-r--r--drivers/media/usb/em28xx/em28xx-i2c.c568
1 files changed, 568 insertions, 0 deletions
diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c
new file mode 100644
index 000000000000..1683bd9d51ee
--- /dev/null
+++ b/drivers/media/usb/em28xx/em28xx-i2c.c
@@ -0,0 +1,568 @@
+/*
+ em28xx-i2c.c - driver for Empia EM2800/EM2820/2840 USB video capture devices
+
+ Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
+ Markus Rechberger <mrechberger@gmail.com>
+ Mauro Carvalho Chehab <mchehab@infradead.org>
+ Sascha Sommer <saschasommer@freenet.de>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/usb.h>
+#include <linux/i2c.h>
+
+#include "em28xx.h"
+#include "tuner-xc2028.h"
+#include <media/v4l2-common.h>
+#include <media/tuner.h>
+
+/* ----------------------------------------------------------- */
+
+static unsigned int i2c_scan;
+module_param(i2c_scan, int, 0444);
+MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
+
+static unsigned int i2c_debug;
+module_param(i2c_debug, int, 0644);
+MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]");
+
+#define dprintk2(lvl, fmt, args...) \
+do { \
+ if (i2c_debug >= lvl) { \
+ printk(KERN_DEBUG "%s at %s: " fmt, \
+ dev->name, __func__ , ##args); \
+ } \
+} while (0)
+
+/*
+ * em2800_i2c_send_max4()
+ * send up to 4 bytes to the i2c device
+ */
+static int em2800_i2c_send_max4(struct em28xx *dev, unsigned char addr,
+ char *buf, int len)
+{
+ int ret;
+ int write_timeout;
+ unsigned char b2[6];
+ BUG_ON(len < 1 || len > 4);
+ b2[5] = 0x80 + len - 1;
+ b2[4] = addr;
+ b2[3] = buf[0];
+ if (len > 1)
+ b2[2] = buf[1];
+ if (len > 2)
+ b2[1] = buf[2];
+ if (len > 3)
+ b2[0] = buf[3];
+
+ ret = dev->em28xx_write_regs(dev, 4 - len, &b2[4 - len], 2 + len);
+ if (ret != 2 + len) {
+ em28xx_warn("writing to i2c device failed (error=%i)\n", ret);
+ return -EIO;
+ }
+ for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
+ write_timeout -= 5) {
+ ret = dev->em28xx_read_reg(dev, 0x05);
+ if (ret == 0x80 + len - 1)
+ return len;
+ msleep(5);
+ }
+ em28xx_warn("i2c write timed out\n");
+ return -EIO;
+}
+
+/*
+ * em2800_i2c_send_bytes()
+ */
+static int em2800_i2c_send_bytes(void *data, unsigned char addr, char *buf,
+ short len)
+{
+ char *bufPtr = buf;
+ int ret;
+ int wrcount = 0;
+ int count;
+ int maxLen = 4;
+ struct em28xx *dev = (struct em28xx *)data;
+ while (len > 0) {
+ count = (len > maxLen) ? maxLen : len;
+ ret = em2800_i2c_send_max4(dev, addr, bufPtr, count);
+ if (ret > 0) {
+ len -= count;
+ bufPtr += count;
+ wrcount += count;
+ } else
+ return (ret < 0) ? ret : -EFAULT;
+ }
+ return wrcount;
+}
+
+/*
+ * em2800_i2c_check_for_device()
+ * check if there is a i2c_device at the supplied address
+ */
+static int em2800_i2c_check_for_device(struct em28xx *dev, unsigned char addr)
+{
+ char msg;
+ int ret;
+ int write_timeout;
+ msg = addr;
+ ret = dev->em28xx_write_regs(dev, 0x04, &msg, 1);
+ if (ret < 0) {
+ em28xx_warn("setting i2c device address failed (error=%i)\n",
+ ret);
+ return ret;
+ }
+ msg = 0x84;
+ ret = dev->em28xx_write_regs(dev, 0x05, &msg, 1);
+ if (ret < 0) {
+ em28xx_warn("preparing i2c read failed (error=%i)\n", ret);
+ return ret;
+ }
+ for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
+ write_timeout -= 5) {
+ unsigned reg = dev->em28xx_read_reg(dev, 0x5);
+
+ if (reg == 0x94)
+ return -ENODEV;
+ else if (reg == 0x84)
+ return 0;
+ msleep(5);
+ }
+ return -ENODEV;
+}
+
+/*
+ * em2800_i2c_recv_bytes()
+ * read from the i2c device
+ */
+static int em2800_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
+ char *buf, int len)
+{
+ int ret;
+ /* check for the device and set i2c read address */
+ ret = em2800_i2c_check_for_device(dev, addr);
+ if (ret) {
+ em28xx_warn
+ ("preparing read at i2c address 0x%x failed (error=%i)\n",
+ addr, ret);
+ return ret;
+ }
+ ret = dev->em28xx_read_reg_req_len(dev, 0x0, 0x3, buf, len);
+ if (ret < 0) {
+ em28xx_warn("reading from i2c device at 0x%x failed (error=%i)",
+ addr, ret);
+ return ret;
+ }
+ return ret;
+}
+
+/*
+ * em28xx_i2c_send_bytes()
+ */
+static int em28xx_i2c_send_bytes(void *data, unsigned char addr, char *buf,
+ short len, int stop)
+{
+ int wrcount = 0;
+ struct em28xx *dev = (struct em28xx *)data;
+ int write_timeout, ret;
+
+ wrcount = dev->em28xx_write_regs_req(dev, stop ? 2 : 3, addr, buf, len);
+
+ /* Seems to be required after a write */
+ for (write_timeout = EM2800_I2C_WRITE_TIMEOUT; write_timeout > 0;
+ write_timeout -= 5) {
+ ret = dev->em28xx_read_reg(dev, 0x05);
+ if (!ret)
+ break;
+ msleep(5);
+ }
+
+ return wrcount;
+}
+
+/*
+ * em28xx_i2c_recv_bytes()
+ * read a byte from the i2c device
+ */
+static int em28xx_i2c_recv_bytes(struct em28xx *dev, unsigned char addr,
+ char *buf, int len)
+{
+ int ret;
+ ret = dev->em28xx_read_reg_req_len(dev, 2, addr, buf, len);
+ if (ret < 0) {
+ em28xx_warn("reading i2c device failed (error=%i)\n", ret);
+ return ret;
+ }
+ if (dev->em28xx_read_reg(dev, 0x5) != 0)
+ return -ENODEV;
+ return ret;
+}
+
+/*
+ * em28xx_i2c_check_for_device()
+ * check if there is a i2c_device at the supplied address
+ */
+static int em28xx_i2c_check_for_device(struct em28xx *dev, unsigned char addr)
+{
+ int ret;
+
+ ret = dev->em28xx_read_reg_req(dev, 2, addr);
+ if (ret < 0) {
+ em28xx_warn("reading from i2c device failed (error=%i)\n", ret);
+ return ret;
+ }
+ if (dev->em28xx_read_reg(dev, 0x5) != 0)
+ return -ENODEV;
+ return 0;
+}
+
+/*
+ * em28xx_i2c_xfer()
+ * the main i2c transfer function
+ */
+static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
+ struct i2c_msg msgs[], int num)
+{
+ struct em28xx *dev = i2c_adap->algo_data;
+ int addr, rc, i, byte;
+
+ if (num <= 0)
+ return 0;
+ for (i = 0; i < num; i++) {
+ addr = msgs[i].addr << 1;
+ dprintk2(2, "%s %s addr=%x len=%d:",
+ (msgs[i].flags & I2C_M_RD) ? "read" : "write",
+ i == num - 1 ? "stop" : "nonstop", addr, msgs[i].len);
+ if (!msgs[i].len) { /* no len: check only for device presence */
+ if (dev->board.is_em2800)
+ rc = em2800_i2c_check_for_device(dev, addr);
+ else
+ rc = em28xx_i2c_check_for_device(dev, addr);
+ if (rc < 0) {
+ dprintk2(2, " no device\n");
+ return rc;
+ }
+
+ } else if (msgs[i].flags & I2C_M_RD) {
+ /* read bytes */
+ if (dev->board.is_em2800)
+ rc = em2800_i2c_recv_bytes(dev, addr,
+ msgs[i].buf,
+ msgs[i].len);
+ else
+ rc = em28xx_i2c_recv_bytes(dev, addr,
+ msgs[i].buf,
+ msgs[i].len);
+ if (i2c_debug >= 2) {
+ for (byte = 0; byte < msgs[i].len; byte++)
+ printk(" %02x", msgs[i].buf[byte]);
+ }
+ } else {
+ /* write bytes */
+ if (i2c_debug >= 2) {
+ for (byte = 0; byte < msgs[i].len; byte++)
+ printk(" %02x", msgs[i].buf[byte]);
+ }
+ if (dev->board.is_em2800)
+ rc = em2800_i2c_send_bytes(dev, addr,
+ msgs[i].buf,
+ msgs[i].len);
+ else
+ rc = em28xx_i2c_send_bytes(dev, addr,
+ msgs[i].buf,
+ msgs[i].len,
+ i == num - 1);
+ }
+ if (rc < 0)
+ goto err;
+ if (i2c_debug >= 2)
+ printk("\n");
+ }
+
+ return num;
+err:
+ dprintk2(2, " ERROR: %i\n", rc);
+ return rc;
+}
+
+/* based on linux/sunrpc/svcauth.h and linux/hash.h
+ * The original hash function returns a different value, if arch is x86_64
+ * or i386.
+ */
+static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
+{
+ unsigned long hash = 0;
+ unsigned long l = 0;
+ int len = 0;
+ unsigned char c;
+ do {
+ if (len == length) {
+ c = (char)len;
+ len = -1;
+ } else
+ c = *buf++;
+ l = (l << 8) | c;
+ len++;
+ if ((len & (32 / 8 - 1)) == 0)
+ hash = ((hash^l) * 0x9e370001UL);
+ } while (len);
+
+ return (hash >> (32 - bits)) & 0xffffffffUL;
+}
+
+static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
+{
+ unsigned char buf, *p = eedata;
+ struct em28xx_eeprom *em_eeprom = (void *)eedata;
+ int i, err, size = len, block;
+
+ if (dev->chip_id == CHIP_ID_EM2874 ||
+ dev->chip_id == CHIP_ID_EM28174 ||
+ dev->chip_id == CHIP_ID_EM2884) {
+ /* Empia switched to a 16-bit addressable eeprom in newer
+ devices. While we could certainly write a routine to read
+ the eeprom, there is nothing of use in there that cannot be
+ accessed through registers, and there is the risk that we
+ could corrupt the eeprom (since a 16-bit read call is
+ interpreted as a write call by 8-bit eeproms).
+ */
+ return 0;
+ }
+
+ dev->i2c_client.addr = 0xa0 >> 1;
+
+ /* Check if board has eeprom */
+ err = i2c_master_recv(&dev->i2c_client, &buf, 0);
+ if (err < 0) {
+ em28xx_errdev("board has no eeprom\n");
+ memset(eedata, 0, len);
+ return -ENODEV;
+ }
+
+ buf = 0;
+
+ err = i2c_master_send(&dev->i2c_client, &buf, 1);
+ if (err != 1) {
+ printk(KERN_INFO "%s: Huh, no eeprom present (err=%d)?\n",
+ dev->name, err);
+ return err;
+ }
+ while (size > 0) {
+ if (size > 16)
+ block = 16;
+ else
+ block = size;
+
+ if (block !=
+ (err = i2c_master_recv(&dev->i2c_client, p, block))) {
+ printk(KERN_WARNING
+ "%s: i2c eeprom read error (err=%d)\n",
+ dev->name, err);
+ return err;
+ }
+ size -= block;
+ p += block;
+ }
+ for (i = 0; i < len; i++) {
+ if (0 == (i % 16))
+ printk(KERN_INFO "%s: i2c eeprom %02x:", dev->name, i);
+ printk(" %02x", eedata[i]);
+ if (15 == (i % 16))
+ printk("\n");
+ }
+
+ if (em_eeprom->id == 0x9567eb1a)
+ dev->hash = em28xx_hash_mem(eedata, len, 32);
+
+ printk(KERN_INFO "%s: EEPROM ID= 0x%08x, EEPROM hash = 0x%08lx\n",
+ dev->name, em_eeprom->id, dev->hash);
+
+ printk(KERN_INFO "%s: EEPROM info:\n", dev->name);
+
+ switch (em_eeprom->chip_conf >> 4 & 0x3) {
+ case 0:
+ printk(KERN_INFO "%s:\tNo audio on board.\n", dev->name);
+ break;
+ case 1:
+ printk(KERN_INFO "%s:\tAC97 audio (5 sample rates)\n",
+ dev->name);
+ break;
+ case 2:
+ printk(KERN_INFO "%s:\tI2S audio, sample rate=32k\n",
+ dev->name);
+ break;
+ case 3:
+ printk(KERN_INFO "%s:\tI2S audio, 3 sample rates\n",
+ dev->name);
+ break;
+ }
+
+ if (em_eeprom->chip_conf & 1 << 3)
+ printk(KERN_INFO "%s:\tUSB Remote wakeup capable\n", dev->name);
+
+ if (em_eeprom->chip_conf & 1 << 2)
+ printk(KERN_INFO "%s:\tUSB Self power capable\n", dev->name);
+
+ switch (em_eeprom->chip_conf & 0x3) {
+ case 0:
+ printk(KERN_INFO "%s:\t500mA max power\n", dev->name);
+ break;
+ case 1:
+ printk(KERN_INFO "%s:\t400mA max power\n", dev->name);
+ break;
+ case 2:
+ printk(KERN_INFO "%s:\t300mA max power\n", dev->name);
+ break;
+ case 3:
+ printk(KERN_INFO "%s:\t200mA max power\n", dev->name);
+ break;
+ }
+ printk(KERN_INFO "%s:\tTable at 0x%02x, strings=0x%04x, 0x%04x, 0x%04x\n",
+ dev->name,
+ em_eeprom->string_idx_table,
+ em_eeprom->string1,
+ em_eeprom->string2,
+ em_eeprom->string3);
+
+ return 0;
+}
+
+/* ----------------------------------------------------------- */
+
+/*
+ * functionality()
+ */
+static u32 functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm em28xx_algo = {
+ .master_xfer = em28xx_i2c_xfer,
+ .functionality = functionality,
+};
+
+static struct i2c_adapter em28xx_adap_template = {
+ .owner = THIS_MODULE,
+ .name = "em28xx",
+ .algo = &em28xx_algo,
+};
+
+static struct i2c_client em28xx_client_template = {
+ .name = "em28xx internal",
+};
+
+/* ----------------------------------------------------------- */
+
+/*
+ * i2c_devs
+ * incomplete list of known devices
+ */
+static char *i2c_devs[128] = {
+ [0x4a >> 1] = "saa7113h",
+ [0x52 >> 1] = "drxk",
+ [0x60 >> 1] = "remote IR sensor",
+ [0x8e >> 1] = "remote IR sensor",
+ [0x86 >> 1] = "tda9887",
+ [0x80 >> 1] = "msp34xx",
+ [0x88 >> 1] = "msp34xx",
+ [0xa0 >> 1] = "eeprom",
+ [0xb0 >> 1] = "tda9874",
+ [0xb8 >> 1] = "tvp5150a",
+ [0xba >> 1] = "webcam sensor or tvp5150a",
+ [0xc0 >> 1] = "tuner (analog)",
+ [0xc2 >> 1] = "tuner (analog)",
+ [0xc4 >> 1] = "tuner (analog)",
+ [0xc6 >> 1] = "tuner (analog)",
+};
+
+/*
+ * do_i2c_scan()
+ * check i2c address range for devices
+ */
+void em28xx_do_i2c_scan(struct em28xx *dev)
+{
+ u8 i2c_devicelist[128];
+ unsigned char buf;
+ int i, rc;
+
+ memset(i2c_devicelist, 0, ARRAY_SIZE(i2c_devicelist));
+
+ for (i = 0; i < ARRAY_SIZE(i2c_devs); i++) {
+ dev->i2c_client.addr = i;
+ rc = i2c_master_recv(&dev->i2c_client, &buf, 0);
+ if (rc < 0)
+ continue;
+ i2c_devicelist[i] = i;
+ printk(KERN_INFO "%s: found i2c device @ 0x%x [%s]\n",
+ dev->name, i << 1, i2c_devs[i] ? i2c_devs[i] : "???");
+ }
+
+ dev->i2c_hash = em28xx_hash_mem(i2c_devicelist,
+ ARRAY_SIZE(i2c_devicelist), 32);
+}
+
+/*
+ * em28xx_i2c_register()
+ * register i2c bus
+ */
+int em28xx_i2c_register(struct em28xx *dev)
+{
+ int retval;
+
+ BUG_ON(!dev->em28xx_write_regs || !dev->em28xx_read_reg);
+ BUG_ON(!dev->em28xx_write_regs_req || !dev->em28xx_read_reg_req);
+ dev->i2c_adap = em28xx_adap_template;
+ dev->i2c_adap.dev.parent = &dev->udev->dev;
+ strcpy(dev->i2c_adap.name, dev->name);
+ dev->i2c_adap.algo_data = dev;
+ i2c_set_adapdata(&dev->i2c_adap, &dev->v4l2_dev);
+
+ retval = i2c_add_adapter(&dev->i2c_adap);
+ if (retval < 0) {
+ em28xx_errdev("%s: i2c_add_adapter failed! retval [%d]\n",
+ __func__, retval);
+ return retval;
+ }
+
+ dev->i2c_client = em28xx_client_template;
+ dev->i2c_client.adapter = &dev->i2c_adap;
+
+ retval = em28xx_i2c_eeprom(dev, dev->eedata, sizeof(dev->eedata));
+ if ((retval < 0) && (retval != -ENODEV)) {
+ em28xx_errdev("%s: em28xx_i2_eeprom failed! retval [%d]\n",
+ __func__, retval);
+
+ return retval;
+ }
+
+ if (i2c_scan)
+ em28xx_do_i2c_scan(dev);
+
+ return 0;
+}
+
+/*
+ * em28xx_i2c_unregister()
+ * unregister i2c_bus
+ */
+int em28xx_i2c_unregister(struct em28xx *dev)
+{
+ i2c_del_adapter(&dev->i2c_adap);
+ return 0;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.