drm/sun4i: hdmi: create a regmap for later use

The HDMI driver is written with readl/writel I/O to the registers.
However, to support the A31 variant, which has a different layout
for the DDC registers, it was recommended to use regfields to have
a cleaner implementation. To use regfields, we need to create an
underlying regmap.

This patch only adds the regmap. It does not convert the existing
driver accesses to use regmap.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171010032008.682-5-wens@csie.org

2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi.h b/drivers/gpu/drm/sun4i/sun4i_hdmi.h
index a1f8cba251a2..aef157d3b659 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi.h
@@ -163,6 +163,7 @@ struct sun4i_hdmi {
         struct device           *dev;
 
         void __iomem            *base;
+        struct regmap           *regmap;
 
         /* Parent clocks */
         struct clk              *bus_clk;
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
index 3cf1a6932fac..5ab811cda00e 100644
--- a/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c
@@ -22,6 +22,7 @@
 #include <linux/iopoll.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/regmap.h>
 
 #include "sun4i_backend.h"
 #include "sun4i_crtc.h"
@@ -267,6 +268,13 @@ static const struct cec_pin_ops sun4i_hdmi_cec_pin_ops = {
 };
 #endif
 
+static const struct regmap_config sun4i_hdmi_regmap_config = {
+        .reg_bits       = 32,
+        .val_bits       = 32,
+        .reg_stride     = 4,
+        .max_register   = 0x580,
+};
+
 static int sun4i_hdmi_bind(struct device *dev, struct device *master,
                            void *data)
 {
@@ -321,6 +329,13 @@ static int sun4i_hdmi_bind(struct device *dev, struct device *master,
                 goto err_disable_mod_clk;
         }
 
+        hdmi->regmap = devm_regmap_init_mmio(dev, hdmi->base,
+                                             &sun4i_hdmi_regmap_config);
+        if (IS_ERR(hdmi->regmap)) {
+                dev_err(dev, "Couldn't create HDMI encoder regmap\n");
+                return PTR_ERR(hdmi->regmap);
+        }
+
         ret = sun4i_tmds_create(hdmi);
         if (ret) {
                 dev_err(dev, "Couldn't create the TMDS clock\n");