@@ -49,6 +49,8 @@
#define CLK_TX_DELAY_MASK GENMASK(19, 16)
#define CLK_RX_DELAY_MASK GENMASK(23, 20)
#define CLK_DELAY_STEP_PS 200
+#define CLK_PHASE_STEP 30
+#define CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
#define CLK_ALWAYS_ON BIT(24)
#define SD_EMMC_DELAY 0x4
@@ -119,12 +121,6 @@
#define MUX_CLK_NUM_PARENTS 2
-struct meson_tuning_params {
- unsigned int core_phase;
- unsigned int tx_phase;
- unsigned int rx_phase;
-};
-
struct sd_emmc_desc {
u32 cmd_cfg;
u32 cmd_arg;
@@ -155,7 +151,6 @@ struct meson_host {
struct sd_emmc_desc *descs;
dma_addr_t descs_dma_addr;
- struct meson_tuning_params tp;
bool vqmmc_enabled;
};
@@ -458,13 +453,6 @@ static int meson_mmc_clk_set(struct meson_host *host, struct mmc_ios *ios)
return 0;
}
-static void meson_mmc_set_phase_params(struct meson_host *host)
-{
- clk_set_phase(host->mmc_clk, host->tp.core_phase);
- clk_set_phase(host->tx_clk, host->tp.tx_phase);
- clk_set_phase(host->rx_clk, host->tp.rx_phase);
-}
-
/*
* The SD/eMMC IP block has an internal mux and divider used for
* generating the MMC clock. Use the clock framework to create and
@@ -617,18 +605,122 @@ static int meson_mmc_clk_init(struct meson_host *host)
if (WARN_ON(PTR_ERR_OR_ZERO(host->rx_clk)))
return PTR_ERR(host->rx_clk);
- /* Set the initial phase parameters */
- meson_mmc_set_phase_params(host);
-
/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
host->mmc->f_min = clk_round_rate(host->mmc_clk, 400000);
ret = clk_set_rate(host->mmc_clk, host->mmc->f_min);
if (ret)
return ret;
+ /*
+ * Set phases : These values are mostly the datasheet recommended ones
+ * except for the Tx phase. Datasheet recommends 180 but some cards
+ * fail at initialisation with it. 270 works just fine, it fixes these
+ * initialisation issues and enable eMMC DDR52 mode.
+ */
+ clk_set_phase(host->mmc_clk, 180);
+ clk_set_phase(host->tx_clk, 270);
+ clk_set_phase(host->rx_clk, 0);
+
return clk_prepare_enable(host->mmc_clk);
}
+static void meson_mmc_shift_map(unsigned long *map, unsigned long shift)
+{
+ DECLARE_BITMAP(left, CLK_PHASE_POINT_NUM);
+ DECLARE_BITMAP(right, CLK_PHASE_POINT_NUM);
+
+ /*
+ * shift the bitmap right and reintroduce the dropped bits on the left
+ * of the bitmap
+ */
+ bitmap_shift_right(right, map, shift, CLK_PHASE_POINT_NUM);
+ bitmap_shift_left(left, map, CLK_PHASE_POINT_NUM - shift,
+ CLK_PHASE_POINT_NUM);
+ bitmap_or(map, left, right, CLK_PHASE_POINT_NUM);
+}
+
+static void meson_mmc_find_next_region(unsigned long *map,
+ unsigned long *start,
+ unsigned long *stop)
+{
+ *start = find_next_bit(map, CLK_PHASE_POINT_NUM, *start);
+ *stop = find_next_zero_bit(map, CLK_PHASE_POINT_NUM, *start);
+}
+
+static int meson_mmc_find_tuning_point(unsigned long *test)
+{
+ unsigned long shift, stop, offset = 0, start = 0, size = 0;
+
+ /* Get the all good/all bad situation out the way */
+ if (bitmap_full(test, CLK_PHASE_POINT_NUM))
+ return 0; /* All points are good so point 0 will do */
+ else if (bitmap_empty(test, CLK_PHASE_POINT_NUM))
+ return -EIO; /* No successful tuning point */
+
+ /*
+ * Now we know there is a least one region find. Make sure it does
+ * not wrap by the shifting the bitmap if necessary
+ */
+ shift = find_first_zero_bit(test, CLK_PHASE_POINT_NUM);
+ if (shift != 0)
+ meson_mmc_shift_map(test, shift);
+
+ while (start < CLK_PHASE_POINT_NUM) {
+ meson_mmc_find_next_region(test, &start, &stop);
+
+ if ((stop - start) > size) {
+ offset = start;
+ size = stop - start;
+ }
+
+ start = stop;
+ }
+
+ /* Get the center point of the region */
+ offset += (size / 2);
+
+ /* Shift the result back */
+ offset = (offset + shift) % CLK_PHASE_POINT_NUM;
+
+ return offset;
+}
+
+static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
+ struct clk *clk)
+{
+ int point, ret;
+ DECLARE_BITMAP(test, CLK_PHASE_POINT_NUM);
+
+ dev_dbg(mmc_dev(mmc), "%s phase/delay tunning...\n",
+ __clk_get_name(clk));
+ bitmap_zero(test, CLK_PHASE_POINT_NUM);
+
+ /* Explore tuning points */
+ for (point = 0; point < CLK_PHASE_POINT_NUM; point++) {
+ clk_set_phase(clk, point * CLK_PHASE_STEP);
+ ret = mmc_send_tuning(mmc, opcode, NULL);
+ if (!ret)
+ set_bit(point, test);
+ }
+
+ /* Find the optimal tuning point and apply it */
+ point = meson_mmc_find_tuning_point(test);
+ if (point < 0)
+ return point; /* tuning failed */
+
+ clk_set_phase(clk, point * CLK_PHASE_STEP);
+ dev_dbg(mmc_dev(mmc), "success with phase: %d\n",
+ clk_get_phase(clk));
+ return 0;
+}
+
+static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ struct meson_host *host = mmc_priv(mmc);
+
+ return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
+}
+
static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
{
struct meson_host *host = mmc_priv(mmc);
@@ -667,6 +759,8 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
host->vqmmc_enabled = true;
}
+ /* Reset rx phase */
+ clk_set_phase(host->rx_clk, 0);
break;
}
@@ -990,29 +1084,6 @@ static irqreturn_t meson_mmc_irq_thread(int irq, void *dev_id)
return IRQ_HANDLED;
}
-static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
-{
- struct meson_host *host = mmc_priv(mmc);
- struct meson_tuning_params tp_old = host->tp;
- int ret = -EINVAL, i, cmd_error;
-
- dev_info(mmc_dev(mmc), "(re)tuning...\n");
-
- for (i = 0; i < 360; i += 90) {
- host->tp.rx_phase = i;
- /* exclude the active parameter set if retuning */
- if (!memcmp(&tp_old, &host->tp, sizeof(tp_old)) &&
- mmc->doing_retune)
- continue;
- meson_mmc_set_phase_params(host);
- ret = mmc_send_tuning(mmc, opcode, &cmd_error);
- if (!ret)
- break;
- }
-
- return ret;
-}
-
/*
* NOTE: we only need this until the GPIO/pinctrl driver can handle
* interrupts. For now, the MMC core will use this for polling.
@@ -1158,16 +1229,6 @@ static int meson_mmc_probe(struct platform_device *pdev)
if (ret)
goto free_host;
- /*
- * Set phases : These values are mostly the datasheet recommended ones
- * except for the Tx phase. Datasheet recommends 180 but some cards
- * fail at initialisation with it. 270 works just fine, it fixes these
- * initialisation issues and enable eMMC DDR52 mode.
- */
- host->tp.core_phase = 180;
- host->tp.tx_phase = 270;
- host->tp.rx_phase = 0;
-
ret = meson_mmc_clk_init(host);
if (ret)
goto err_core_clk;