iio: adc: ad9361: GPO support via debugfs

This adds support for dynamic GPO[0..3] control via a new debugfs
attribute gpo_set. adi,gpo-manual-mode-enable must be enabled.
Be aware that GPO manual mode can conflict with external LNA and
automatic ENSM slave mode. GPOs can be addressed individual 0..3 or
altogether using 0xF as address select.

Example:
# cd /sys/kernel/debug/iio/iio\:device1
# echo 1 > adi,gpo-manual-mode-enable
# echo 0 1 > gpo_set
# echo 0 0 > gpo_set
# echo 0xF 0xF > gpo_set
# echo 0xF 0 > gpo_set

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>

drivers/iio/adc/ad9361.c

@@ -8142,7 +8142,8 @@ static ssize_t ad9361_debugfs_write(struct file *file,
 {
 	struct ad9361_debugfs_entry *entry = file->private_data;
 	struct ad9361_rf_phy *phy = entry->phy;
-	u32 val, val2, val3, val4;
+	struct gpo_control *ctrl = &phy->pdata->gpo_ctrl;
+	u32 val, val2, val3, val4, mask;
 	char buf[80];
 	int ret;
 
@@ -8247,6 +8248,60 @@ static ssize_t ad9361_debugfs_write(struct file *file,
 		entry->val = val;
 		return count;
 	case DBGFS_BIST_DT_ANALYSIS:
+		entry->val = val;
+		return count;
+	case DBGFS_GPO_SET:
+		if (ret != 2)
+			return -EINVAL;
+
+		if (!ctrl->gpo_manual_mode_en) {
+			dev_warn(&phy->spi->dev, "GPO manual mode not enabled!");
+			return -EINVAL;
+		}
+
+		switch (val) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+			mask = BIT(val);
+			if (val2)
+				val3 = mask;
+			else
+				val3 = 0;
+			break;
+		case 0xF:
+			mask = 0xF;
+			val3 = val2 & 0xF;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		mutex_lock(&phy->indio_dev->mlock);
+		ctrl->gpo_manual_mode_enable_mask &= ~mask;
+		ctrl->gpo_manual_mode_enable_mask |= val3;
+
+		ret = ad9361_spi_write(phy->spi, REG_GPO_FORCE_AND_INIT,
+			GPO_MANUAL_CTRL(ctrl->gpo_manual_mode_enable_mask) |
+			GPO_INIT_STATE(ctrl->gpo0_inactive_state_high_en |
+			(ctrl->gpo1_inactive_state_high_en << 1) |
+			(ctrl->gpo2_inactive_state_high_en << 2) |
+			(ctrl->gpo3_inactive_state_high_en << 3)));
+
+		/*
+		 * GPO manual mode conflicts with automatic ENSM slave
+		 * and eLNA mode
+		 */
+
+		val3 = ad9361_spi_read(phy->spi, REG_EXTERNAL_LNA_CTRL);
+		if (!(val3 & GPO_MANUAL_SELECT))
+			ad9361_spi_write(phy->spi, REG_EXTERNAL_LNA_CTRL,
+					 val3 | GPO_MANUAL_SELECT);
+		mutex_unlock(&phy->indio_dev->mlock);
+		if (ret < 0)
+			return ret;
+
 		entry->val = val;
 		return count;
 	default:
@@ -8310,6 +8365,7 @@ static int ad9361_register_debugfs(struct iio_dev *indio_dev)
 	ad9361_add_debugfs_entry(phy, "loopback", DBGFS_LOOPBACK);
 	ad9361_add_debugfs_entry(phy, "bist_prbs", DBGFS_BIST_PRBS);
 	ad9361_add_debugfs_entry(phy, "bist_tone", DBGFS_BIST_TONE);
+	ad9361_add_debugfs_entry(phy, "gpo_set", DBGFS_GPO_SET);
 	ad9361_add_debugfs_entry(phy, "bist_timing_analysis",
 		DBGFS_BIST_DT_ANALYSIS);
 	ad9361_add_debugfs_entry(phy, "gaininfo_rx1", DBGFS_RXGAIN_1);

drivers/iio/adc/ad9361.h

@@ -47,6 +47,7 @@ enum debugfs_cmd {
 	DBGFS_MCS,
 	DBGFS_CAL_SW_CTRL,
 	DBGFS_DIGITAL_TUNE,
+	DBGFS_GPO_SET,
 };
 
 enum dig_tune_flags {
@@ -138,7 +139,7 @@ struct ad9361_rf_phy {
 	struct refclk_scale	clk_priv[NUM_AD9361_CLKS];
 	struct clk_onecell_data	clk_data;
 	struct ad9361_phy_platform_data *pdata;
-	struct ad9361_debugfs_entry debugfs_entry[181];
+	struct ad9361_debugfs_entry debugfs_entry[182];
 	struct bin_attribute 	bin;
 	struct bin_attribute 	bin_gt;
 	struct iio_dev 		*indio_dev;