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-rw-r--r--drivers/gpu/drm/nouveau/nouveau_i2c.c199
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_i2c.h1
2 files changed, 178 insertions, 22 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_i2c.c b/drivers/gpu/drm/nouveau/nouveau_i2c.c
index 116ef3193fc7..820ae7f52044 100644
--- a/drivers/gpu/drm/nouveau/nouveau_i2c.c
+++ b/drivers/gpu/drm/nouveau/nouveau_i2c.c
@@ -29,6 +29,10 @@
#include "nouveau_i2c.h"
#include "nouveau_hw.h"
+#define T_TIMEOUT 2200000
+#define T_RISEFALL 1000
+#define T_HOLD 5000
+
static void
i2c_drive_scl(void *data, int state)
{
@@ -109,6 +113,175 @@ i2c_sense_sda(void *data)
return 0;
}
+static void
+i2c_delay(struct nouveau_i2c_chan *port, u32 nsec)
+{
+ udelay((nsec + 500) / 1000);
+}
+
+static bool
+i2c_raise_scl(struct nouveau_i2c_chan *port)
+{
+ u32 timeout = T_TIMEOUT / T_RISEFALL;
+
+ i2c_drive_scl(port, 1);
+ do {
+ i2c_delay(port, T_RISEFALL);
+ } while (!i2c_sense_scl(port) && --timeout);
+
+ return timeout != 0;
+}
+
+static int
+i2c_start(struct nouveau_i2c_chan *port)
+{
+ int ret = 0;
+
+ port->state = i2c_sense_scl(port);
+ port->state |= i2c_sense_sda(port) << 1;
+ if (port->state != 3) {
+ i2c_drive_scl(port, 0);
+ i2c_drive_sda(port, 1);
+ if (!i2c_raise_scl(port))
+ ret = -EBUSY;
+ }
+
+ i2c_drive_sda(port, 0);
+ i2c_delay(port, T_HOLD);
+ i2c_drive_scl(port, 0);
+ i2c_delay(port, T_HOLD);
+ return ret;
+}
+
+static void
+i2c_stop(struct nouveau_i2c_chan *port)
+{
+ i2c_drive_scl(port, 0);
+ i2c_drive_sda(port, 0);
+ i2c_delay(port, T_RISEFALL);
+
+ i2c_drive_scl(port, 1);
+ i2c_delay(port, T_HOLD);
+ i2c_drive_sda(port, 1);
+ i2c_delay(port, T_HOLD);
+}
+
+static int
+i2c_bitw(struct nouveau_i2c_chan *port, int sda)
+{
+ i2c_drive_sda(port, sda);
+ i2c_delay(port, T_RISEFALL);
+
+ if (!i2c_raise_scl(port))
+ return -ETIMEDOUT;
+ i2c_delay(port, T_HOLD);
+
+ i2c_drive_scl(port, 0);
+ i2c_delay(port, T_HOLD);
+ return 0;
+}
+
+static int
+i2c_bitr(struct nouveau_i2c_chan *port)
+{
+ int sda;
+
+ i2c_drive_sda(port, 1);
+ i2c_delay(port, T_RISEFALL);
+
+ if (!i2c_raise_scl(port))
+ return -ETIMEDOUT;
+ i2c_delay(port, T_HOLD);
+
+ sda = i2c_sense_sda(port);
+
+ i2c_drive_scl(port, 0);
+ i2c_delay(port, T_HOLD);
+ return sda;
+}
+
+static int
+i2c_get_byte(struct nouveau_i2c_chan *port, u8 *byte, bool last)
+{
+ int i, bit;
+
+ *byte = 0;
+ for (i = 7; i >= 0; i--) {
+ bit = i2c_bitr(port);
+ if (bit < 0)
+ return bit;
+ *byte |= bit << i;
+ }
+
+ return i2c_bitw(port, last ? 1 : 0);
+}
+
+static int
+i2c_put_byte(struct nouveau_i2c_chan *port, u8 byte)
+{
+ int i, ret;
+ for (i = 7; i >= 0; i--) {
+ ret = i2c_bitw(port, !!(byte & (1 << i)));
+ if (ret < 0)
+ return ret;
+ }
+
+ ret = i2c_bitr(port);
+ if (ret == 1) /* nack */
+ ret = -EIO;
+ return ret;
+}
+
+static int
+i2c_addr(struct nouveau_i2c_chan *port, struct i2c_msg *msg)
+{
+ u32 addr = msg->addr << 1;
+ if (msg->flags & I2C_M_RD)
+ addr |= 1;
+ return i2c_put_byte(port, addr);
+}
+
+static int
+i2c_bit_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct nouveau_i2c_chan *port = (struct nouveau_i2c_chan *)adap;
+ struct i2c_msg *msg = msgs;
+ int ret = 0, mcnt = num;
+
+ while (!ret && mcnt--) {
+ u8 remaining = msg->len;
+ u8 *ptr = msg->buf;
+
+ ret = i2c_start(port);
+ if (ret == 0)
+ ret = i2c_addr(port, msg);
+
+ if (msg->flags & I2C_M_RD) {
+ while (!ret && remaining--)
+ ret = i2c_get_byte(port, ptr++, !remaining);
+ } else {
+ while (!ret && remaining--)
+ ret = i2c_put_byte(port, *ptr++);
+ }
+
+ msg++;
+ }
+
+ i2c_stop(port);
+ return (ret < 0) ? ret : num;
+}
+
+static u32
+i2c_bit_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+const struct i2c_algorithm i2c_bit_algo = {
+ .master_xfer = i2c_bit_xfer,
+ .functionality = i2c_bit_func
+};
+
static const uint32_t nv50_i2c_port[] = {
0x00e138, 0x00e150, 0x00e168, 0x00e180,
0x00e254, 0x00e274, 0x00e764, 0x00e780,
@@ -211,10 +384,12 @@ nouveau_i2c_init(struct drm_device *dev)
case 0: /* NV04:NV50 */
port->drive = entry[0];
port->sense = entry[1];
+ port->adapter.algo = &i2c_bit_algo;
break;
case 4: /* NV4E */
port->drive = 0x600800 + entry[1];
port->sense = port->drive;
+ port->adapter.algo = &i2c_bit_algo;
break;
case 5: /* NV50- */
port->drive = entry[0] & 0x0f;
@@ -227,6 +402,7 @@ nouveau_i2c_init(struct drm_device *dev)
port->drive = 0x00d014 + (port->drive * 0x20);
port->sense = port->drive;
}
+ port->adapter.algo = &i2c_bit_algo;
break;
case 6: /* NV50- DP AUX */
port->drive = entry[0];
@@ -237,7 +413,7 @@ nouveau_i2c_init(struct drm_device *dev)
break;
}
- if (!port->adapter.algo && !port->drive) {
+ if (!port->adapter.algo) {
NV_ERROR(dev, "I2C%d: type %d index %x/%x unknown\n",
i, port->type, port->drive, port->sense);
kfree(port);
@@ -253,26 +429,7 @@ nouveau_i2c_init(struct drm_device *dev)
port->dcb = ROM32(entry[0]);
i2c_set_adapdata(&port->adapter, i2c);
- if (port->adapter.algo != &nouveau_dp_i2c_algo) {
- port->adapter.algo_data = &port->bit;
- port->bit.udelay = 40;
- port->bit.timeout = usecs_to_jiffies(5000);
- port->bit.data = port;
- port->bit.setsda = i2c_drive_sda;
- port->bit.setscl = i2c_drive_scl;
- port->bit.getsda = i2c_sense_sda;
- port->bit.getscl = i2c_sense_scl;
-
- i2c_drive_scl(port, 0);
- i2c_drive_sda(port, 1);
- i2c_drive_scl(port, 1);
-
- ret = i2c_bit_add_bus(&port->adapter);
- } else {
- port->adapter.algo = &nouveau_dp_i2c_algo;
- ret = i2c_add_adapter(&port->adapter);
- }
-
+ ret = i2c_add_adapter(&port->adapter);
if (ret) {
NV_ERROR(dev, "I2C%d: failed register: %d\n", i, ret);
kfree(port);
diff --git a/drivers/gpu/drm/nouveau/nouveau_i2c.h b/drivers/gpu/drm/nouveau/nouveau_i2c.h
index 1d083893a4d7..4d2e4e9031be 100644
--- a/drivers/gpu/drm/nouveau/nouveau_i2c.h
+++ b/drivers/gpu/drm/nouveau/nouveau_i2c.h
@@ -34,7 +34,6 @@
struct nouveau_i2c_chan {
struct i2c_adapter adapter;
struct drm_device *dev;
- struct i2c_algo_bit_data bit;
struct list_head head;
u8 index;
u8 type;
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