drm/nouveau/dp: rewrite auxch transaction routines

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

2 files changed, 132 insertions, 105 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_dp.c b/drivers/gpu/drm/nouveau/nouveau_dp.c
index 44de23d9a437..f8ebd09ee3a6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dp.c
@@ -29,6 +29,136 @@
 #include "nouveau_connector.h"
 #include "nouveau_encoder.h"
 
+/******************************************************************************
+ * aux channel util functions
+ *****************************************************************************/
+#define AUX_DBG(fmt, args...) do {                                             \
+        if (nouveau_reg_debug & NOUVEAU_REG_DEBUG_AUXCH) {                     \
+                NV_PRINTK(KERN_DEBUG, dev, "AUXCH(%d): " fmt, ch, ##args);     \
+        }                                                                      \
+} while (0)
+#define AUX_ERR(fmt, args...) NV_ERROR(dev, "AUXCH(%d): " fmt, ch, ##args)
+
+static void
+auxch_fini(struct drm_device *dev, int ch)
+{
+        nv_mask(dev, 0x00e4e4 + (ch * 0x50), 0x00310000, 0x00000000);
+}
+
+static int
+auxch_init(struct drm_device *dev, int ch)
+{
+        const u32 unksel = 1; /* nfi which to use, or if it matters.. */
+        const u32 ureq = unksel ? 0x00100000 : 0x00200000;
+        const u32 urep = unksel ? 0x01000000 : 0x02000000;
+        u32 ctrl, timeout;
+
+        /* wait up to 1ms for any previous transaction to be done... */
+        timeout = 1000;
+        do {
+                ctrl = nv_rd32(dev, 0x00e4e4 + (ch * 0x50));
+                udelay(1);
+                if (!timeout--) {
+                        AUX_ERR("begin idle timeout 0x%08x", ctrl);
+                        return -EBUSY;
+                }
+        } while (ctrl & 0x03010000);
+
+        /* set some magic, and wait up to 1ms for it to appear */
+        nv_mask(dev, 0x00e4e4 + (ch * 0x50), 0x00300000, ureq);
+        timeout = 1000;
+        do {
+                ctrl = nv_rd32(dev, 0x00e4e4 + (ch * 0x50));
+                udelay(1);
+                if (!timeout--) {
+                        AUX_ERR("magic wait 0x%08x\n", ctrl);
+                        auxch_fini(dev, ch);
+                        return -EBUSY;
+                }
+        } while ((ctrl & 0x03000000) != urep);
+
+        return 0;
+}
+
+static int
+auxch_tx(struct drm_device *dev, int ch, u8 type, u32 addr, u8 *data, u8 size)
+{
+        u32 ctrl, stat, timeout, retries;
+        u32 xbuf[4] = {};
+        int ret, i;
+
+        AUX_DBG("%d: 0x%08x %d\n", type, addr, size);
+
+        ret = auxch_init(dev, ch);
+        if (ret)
+                goto out;
+
+        stat = nv_rd32(dev, 0x00e4e8 + (ch * 0x50));
+        if (!(stat & 0x10000000)) {
+                AUX_DBG("sink not detected\n");
+                ret = -ENXIO;
+                goto out;
+        }
+
+        if (!(type & 1)) {
+                memcpy(xbuf, data, size);
+                for (i = 0; i < 16; i += 4) {
+                        AUX_DBG("wr 0x%08x\n", xbuf[i / 4]);
+                        nv_wr32(dev, 0x00e4c0 + (ch * 0x50) + i, xbuf[i / 4]);
+                }
+        }
+
+        ctrl  = nv_rd32(dev, 0x00e4e4 + (ch * 0x50));
+        ctrl &= ~0x0001f0ff;
+        ctrl |= type << 12;
+        ctrl |= size - 1;
+        nv_wr32(dev, 0x00e4e0 + (ch * 0x50), addr);
+
+        /* retry transaction a number of times on failure... */
+        ret = -EREMOTEIO;
+        for (retries = 0; retries < 32; retries++) {
+                /* reset, and delay a while if this is a retry */
+                nv_wr32(dev, 0x00e4e4 + (ch * 0x50), 0x80000000 | ctrl);
+                nv_wr32(dev, 0x00e4e4 + (ch * 0x50), 0x00000000 | ctrl);
+                if (retries)
+                        udelay(400);
+
+                /* transaction request, wait up to 1ms for it to complete */
+                nv_wr32(dev, 0x00e4e4 + (ch * 0x50), 0x00010000 | ctrl);
+
+                timeout = 1000;
+                do {
+                        ctrl = nv_rd32(dev, 0x00e4e4 + (ch * 0x50));
+                        udelay(1);
+                        if (!timeout--) {
+                                AUX_ERR("tx req timeout 0x%08x\n", ctrl);
+                                goto out;
+                        }
+                } while (ctrl & 0x00010000);
+
+                /* read status, and check if transaction completed ok */
+                stat = nv_mask(dev, 0x00e4e8 + (ch * 0x50), 0, 0);
+                if (!(stat & 0x000f0f00)) {
+                        ret = 0;
+                        break;
+                }
+
+                AUX_DBG("%02d 0x%08x 0x%08x\n", retries, ctrl, stat);
+        }
+
+        if (type & 1) {
+                for (i = 0; i < 16; i += 4) {
+                        xbuf[i / 4] = nv_rd32(dev, 0x00e4d0 + (ch * 0x50) + i);
+                        AUX_DBG("rd 0x%08x\n", xbuf[i / 4]);
+                }
+                memcpy(data, xbuf, size);
+        }
+
+out:
+        auxch_fini(dev, ch);
+        return ret;
+}
+
 static int
 auxch_rd(struct drm_encoder *encoder, int address, uint8_t *buf, int size)
 {
@@ -480,98 +610,7 @@ int
 nouveau_dp_auxch(struct nouveau_i2c_chan *auxch, int cmd, int addr,
                  uint8_t *data, int data_nr)
 {
-        struct drm_device *dev = auxch->dev;
-        uint32_t tmp, ctrl, stat = 0, data32[4] = {};
-        int ret = 0, i, index = auxch->rd;
-
-        NV_DEBUG_KMS(dev, "ch %d cmd %d addr 0x%x len %d\n", index, cmd, addr, data_nr);
-
-        tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
-        nv_wr32(dev, NV50_AUXCH_CTRL(auxch->rd), tmp | 0x00100000);
-        tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
-        if (!(tmp & 0x01000000)) {
-                NV_ERROR(dev, "expected bit 24 == 1, got 0x%08x\n", tmp);
-                ret = -EIO;
-                goto out;
-        }
-
-        for (i = 0; i < 3; i++) {
-                tmp = nv_rd32(dev, NV50_AUXCH_STAT(auxch->rd));
-                if (tmp & NV50_AUXCH_STAT_STATE_READY)
-                        break;
-                udelay(100);
-        }
-
-        if (i == 3) {
-                ret = -EBUSY;
-                goto out;
-        }
-
-        if (!(cmd & 1)) {
-                memcpy(data32, data, data_nr);
-                for (i = 0; i < 4; i++) {
-                        NV_DEBUG_KMS(dev, "wr %d: 0x%08x\n", i, data32[i]);
-                        nv_wr32(dev, NV50_AUXCH_DATA_OUT(index, i), data32[i]);
-                }
-        }
-
-        nv_wr32(dev, NV50_AUXCH_ADDR(index), addr);
-        ctrl  = nv_rd32(dev, NV50_AUXCH_CTRL(index));
-        ctrl &= ~(NV50_AUXCH_CTRL_CMD | NV50_AUXCH_CTRL_LEN);
-        ctrl |= (cmd << NV50_AUXCH_CTRL_CMD_SHIFT);
-        ctrl |= ((data_nr - 1) << NV50_AUXCH_CTRL_LEN_SHIFT);
-
-        for (i = 0; i < 16; i++) {
-                nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl | 0x80000000);
-                nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl);
-                nv_wr32(dev, NV50_AUXCH_CTRL(index), ctrl | 0x00010000);
-                if (!nv_wait(dev, NV50_AUXCH_CTRL(index),
-                             0x00010000, 0x00000000)) {
-                        NV_ERROR(dev, "expected bit 16 == 0, got 0x%08x\n",
-                                 nv_rd32(dev, NV50_AUXCH_CTRL(index)));
-                        ret = -EBUSY;
-                        goto out;
-                }
-
-                udelay(400);
-
-                stat = nv_rd32(dev, NV50_AUXCH_STAT(index));
-                if ((stat & NV50_AUXCH_STAT_REPLY_AUX) !=
-                            NV50_AUXCH_STAT_REPLY_AUX_DEFER)
-                        break;
-        }
-
-        if (i == 16) {
-                NV_ERROR(dev, "auxch DEFER too many times, bailing\n");
-                ret = -EREMOTEIO;
-                goto out;
-        }
-
-        if (cmd & 1) {
-                if ((stat & NV50_AUXCH_STAT_COUNT) != data_nr) {
-                        ret = -EREMOTEIO;
-                        goto out;
-                }
-
-                for (i = 0; i < 4; i++) {
-                        data32[i] = nv_rd32(dev, NV50_AUXCH_DATA_IN(index, i));
-                        NV_DEBUG_KMS(dev, "rd %d: 0x%08x\n", i, data32[i]);
-                }
-                memcpy(data, data32, data_nr);
-        }
-
-out:
-        tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
-        nv_wr32(dev, NV50_AUXCH_CTRL(auxch->rd), tmp & ~0x00100000);
-        tmp = nv_rd32(dev, NV50_AUXCH_CTRL(auxch->rd));
-        if (tmp & 0x01000000) {
-                NV_ERROR(dev, "expected bit 24 == 0, got 0x%08x\n", tmp);
-                ret = -EIO;
-        }
-
-        udelay(400);
-
-        return ret ? ret : (stat & NV50_AUXCH_STAT_REPLY);
+        return auxch_tx(auxch->dev, auxch->rd, cmd, addr, data, data_nr);
 }
 
 static int
@@ -602,19 +641,6 @@ nouveau_dp_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
                         if (ret < 0)
                                 return ret;
 
-                        switch (ret & NV50_AUXCH_STAT_REPLY_I2C) {
-                        case NV50_AUXCH_STAT_REPLY_I2C_ACK:
-                                break;
-                        case NV50_AUXCH_STAT_REPLY_I2C_NACK:
-                                return -EREMOTEIO;
-                        case NV50_AUXCH_STAT_REPLY_I2C_DEFER:
-                                udelay(100);
-                                continue;
-                        default:
-                                NV_ERROR(dev, "bad auxch reply: 0x%08x\n", ret);
-                                return -EREMOTEIO;
-                        }
-
                         ptr += cnt;
                         remaining -= cnt;
                 }
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 92c414af2074..bc035c4f42a8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -1570,6 +1570,7 @@ enum {
         NOUVEAU_REG_DEBUG_RMVIO          = 0x80,
         NOUVEAU_REG_DEBUG_VGAATTR        = 0x100,
         NOUVEAU_REG_DEBUG_EVO            = 0x200,
+        NOUVEAU_REG_DEBUG_AUXCH          = 0x400
 };
 
 #define NV_REG_DEBUG(type, dev, fmt, arg...) do { \