drm/mediatek: config mipitx impedance with calibration data

Read calibration data from nvmem, and config mipitx impedance with
calibration data to make sure their impedance are 100ohm.
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_mipi_tx.c

@@ -88,6 +88,44 @@ static const struct phy_ops mtk_mipi_tx_ops = {
 	.owner = THIS_MODULE,
 };
 
+static void mtk_mipi_tx_get_calibration_datal(struct mtk_mipi_tx *mipi_tx)
+{
+	struct nvmem_cell *cell;
+	size_t len;
+	u32 *buf;
+
+	cell = nvmem_cell_get(mipi_tx->dev, "calibration-data");
+	if (IS_ERR(cell)) {
+		dev_info(mipi_tx->dev, "can't get nvmem_cell_get, ignore it\n");
+		return;
+	}
+	buf = (u32 *)nvmem_cell_read(cell, &len);
+	nvmem_cell_put(cell);
+
+	if (IS_ERR(buf)) {
+		dev_info(mipi_tx->dev, "can't get data, ignore it\n");
+		return;
+	}
+
+	if (len < 3 * sizeof(u32)) {
+		dev_info(mipi_tx->dev, "invalid calibration data\n");
+		kfree(buf);
+		return;
+	}
+
+	mipi_tx->rt_code[0] = ((buf[0] >> 6 & 0x1f) << 5) |
+			       (buf[0] >> 11 & 0x1f);
+	mipi_tx->rt_code[1] = ((buf[1] >> 27 & 0x1f) << 5) |
+			       (buf[0] >> 1 & 0x1f);
+	mipi_tx->rt_code[2] = ((buf[1] >> 17 & 0x1f) << 5) |
+			       (buf[1] >> 22 & 0x1f);
+	mipi_tx->rt_code[3] = ((buf[1] >> 7 & 0x1f) << 5) |
+			       (buf[1] >> 12 & 0x1f);
+	mipi_tx->rt_code[4] = ((buf[2] >> 27 & 0x1f) << 5) |
+			       (buf[1] >> 2 & 0x1f);
+	kfree(buf);
+}
+
 static int mtk_mipi_tx_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -174,6 +212,8 @@ static int mtk_mipi_tx_probe(struct platform_device *pdev)
 
 	mipi_tx->dev = dev;
 
+	mtk_mipi_tx_get_calibration_datal(mipi_tx);
+
 	return of_clk_add_provider(dev->of_node, of_clk_src_simple_get,
 				   mipi_tx->pll);
 }

drivers/gpu/drm/mediatek/mtk_mipi_tx.h

@@ -12,9 +12,11 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/nvmem-consumer.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
+#include <linux/slab.h>
 
 struct mtk_mipitx_data {
 	const u32 mppll_preserve;
@@ -28,6 +30,7 @@ struct mtk_mipi_tx {
 	void __iomem *regs;
 	u32 data_rate;
 	u32 mipitx_drive;
+	u32 rt_code[5];
 	const struct mtk_mipitx_data *driver_data;
 	struct clk_hw pll_hw;
 	struct clk *pll;

drivers/gpu/drm/mediatek/mtk_mt8183_mipi_tx.c

@@ -28,6 +28,7 @@
 #define MIPITX_PLL_CON4		0x003c
 #define RG_DSI_PLL_IBIAS		(3 << 10)
 
+#define MIPITX_D2P_RTCODE	0x0100
 #define MIPITX_D2_SW_CTL_EN	0x0144
 #define MIPITX_D0_SW_CTL_EN	0x0244
 #define MIPITX_CK_CKMODE_EN	0x0328
@@ -108,6 +109,24 @@ static const struct clk_ops mtk_mipi_tx_pll_ops = {
 	.recalc_rate = mtk_mipi_tx_pll_recalc_rate,
 };
 
+static void mtk_mipi_tx_config_calibration_data(struct mtk_mipi_tx *mipi_tx)
+{
+	int i, j;
+
+	for (i = 0; i < 5; i++) {
+		if ((mipi_tx->rt_code[i] & 0x1f) == 0)
+			mipi_tx->rt_code[i] |= 0x10;
+
+		if ((mipi_tx->rt_code[i] >> 5 & 0x1f) == 0)
+			mipi_tx->rt_code[i] |= 0x10 << 5;
+
+		for (j = 0; j < 10; j++)
+			mtk_mipi_tx_update_bits(mipi_tx,
+				MIPITX_D2P_RTCODE * (i + 1) + j * 4,
+				1, mipi_tx->rt_code[i] >> j & 1);
+	}
+}
+
 static void mtk_mipi_tx_power_on_signal(struct phy *phy)
 {
 	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
@@ -130,6 +149,8 @@ static void mtk_mipi_tx_power_on_signal(struct phy *phy)
 				RG_DSI_HSTX_LDO_REF_SEL,
 				(mipi_tx->mipitx_drive - 3000) / 200 << 6);
 
+	mtk_mipi_tx_config_calibration_data(mipi_tx);
+
 	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_CK_CKMODE_EN, DSI_CK_CKMODE_EN);
 }