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Subject[PATCH v3 4/4] drm/mediatek: config mipitx impedance with calibration data
Date
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>
---
drivers/gpu/drm/mediatek/mtk_mt8183_mipi_tx.c | 57 +++++++++++++++++++
1 file changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_mt8183_mipi_tx.c b/drivers/gpu/drm/mediatek/mtk_mt8183_mipi_tx.c
index 124fdf95f1e5..878feeb7ac6c 100644
--- a/drivers/gpu/drm/mediatek/mtk_mt8183_mipi_tx.c
+++ b/drivers/gpu/drm/mediatek/mtk_mt8183_mipi_tx.c
@@ -5,6 +5,8 @@
*/

#include "mtk_mipi_tx.h"
+#include <linux/nvmem-consumer.h>
+#include <linux/slab.h>

#define MIPITX_LANE_CON 0x000c
#define RG_DSI_CPHY_T1DRV_EN BIT(0)
@@ -28,6 +30,7 @@
#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 +111,58 @@ 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)
+{
+ u32 *buf;
+ u32 rt_code[5];
+ int i, j;
+ struct nvmem_cell *cell;
+ struct device *dev = mipi_tx->dev;
+ size_t len;
+
+ cell = nvmem_cell_get(dev, "calibration-data");
+ if (IS_ERR(cell)) {
+ dev_info(dev, "nvmem_cell_get fail\n");
+ return;
+ }
+
+ buf = (u32 *)nvmem_cell_read(cell, &len);
+
+ nvmem_cell_put(cell);
+
+ if (IS_ERR(buf)) {
+ dev_info(dev, "can't get data\n");
+ return;
+ }
+
+ if (len < 3 * sizeof(u32)) {
+ dev_info(dev, "invalid calibration data\n");
+ kfree(buf);
+ return;
+ }
+
+ rt_code[0] = ((buf[0] >> 6 & 0x1f) << 5) | (buf[0] >> 11 & 0x1f);
+ rt_code[1] = ((buf[1] >> 27 & 0x1f) << 5) | (buf[0] >> 1 & 0x1f);
+ rt_code[2] = ((buf[1] >> 17 & 0x1f) << 5) | (buf[1] >> 22 & 0x1f);
+ rt_code[3] = ((buf[1] >> 7 & 0x1f) << 5) | (buf[1] >> 12 & 0x1f);
+ rt_code[4] = ((buf[2] >> 27 & 0x1f) << 5) | (buf[1] >> 2 & 0x1f);
+
+ for (i = 0; i < 5; i++) {
+ if ((rt_code[i] & 0x1f) == 0)
+ rt_code[i] |= 0x10;
+
+ if ((rt_code[i] >> 5 & 0x1f) == 0)
+ 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, rt_code[i] >> j & 1);
+ }
+
+ kfree(buf);
+}
+
static void mtk_mipi_tx_power_on_signal(struct phy *phy)
{
struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
@@ -130,6 +185,8 @@ static void mtk_mipi_tx_power_on_signal(struct phy *phy)
RG_DSI_HSTX_LDO_REF_SEL,
mipi_tx->mipitx_drive << 6);

+ mtk_mipi_tx_config_calibration_data(mipi_tx);
+
mtk_mipi_tx_set_bits(mipi_tx, MIPITX_CK_CKMODE_EN, DSI_CK_CKMODE_EN);
}

--
2.21.0
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