video: mb862xx: add support for controller's I2C bus adapter

Add adapter driver for I2C adapter in Coral-P(A)/Lime GDCs.
So we can easily access devices on controller's I2C bus using
i2c-dev interface.

Signed-off-by: Anatolij Gustschin <agust@denx.de>

6 files changed, 224 insertions, 1 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 7326962565ce..549b960667c8 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -2294,6 +2294,15 @@ config FB_MB862XX_LIME
 
 endchoice
 
+config FB_MB862XX_I2C
+        bool "Support I2C bus on MB862XX GDC"
+        depends on FB_MB862XX && I2C
+        default y
+        help
+          Selecting this option adds Coral-P(A)/Lime GDC I2C bus adapter
+          driver to support accessing I2C devices on controller's I2C bus.
+          These are usually some video decoder chips.
+
 config FB_EP93XX
         tristate "EP93XX frame buffer support"
         depends on FB && ARCH_EP93XX
diff --git a/drivers/video/mb862xx/Makefile b/drivers/video/mb862xx/Makefile
index d7777714166b..5707ed0e31a7 100644
--- a/drivers/video/mb862xx/Makefile
+++ b/drivers/video/mb862xx/Makefile
@@ -2,4 +2,7 @@
 # Makefile for the MB862xx framebuffer driver
 #
 
-obj-$(CONFIG_FB_MB862XX)        := mb862xxfb.o mb862xxfb_accel.o
+obj-$(CONFIG_FB_MB862XX) += mb862xxfb.o
+
+mb862xxfb-y := mb862xxfbdrv.o mb862xxfb_accel.o
+mb862xxfb-$(CONFIG_FB_MB862XX_I2C) += mb862xx-i2c.o
diff --git a/drivers/video/mb862xx/mb862xx-i2c.c b/drivers/video/mb862xx/mb862xx-i2c.c
new file mode 100644
index 000000000000..cb77d3b4657d
--- /dev/null
+++ b/drivers/video/mb862xx/mb862xx-i2c.c
@@ -0,0 +1,177 @@
+/*
+ * Coral-P(A)/Lime I2C adapter driver
+ *
+ * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+
+#include "mb862xxfb.h"
+#include "mb862xx_reg.h"
+
+static int mb862xx_i2c_wait_event(struct i2c_adapter *adap)
+{
+        struct mb862xxfb_par *par = adap->algo_data;
+        u32 reg;
+
+        do {
+                udelay(1);
+                reg = inreg(i2c, GC_I2C_BCR);
+                if (reg & (I2C_INT | I2C_BER))
+                        break;
+        } while (1);
+
+        return (reg & I2C_BER) ? 0 : 1;
+}
+
+static int mb862xx_i2c_do_address(struct i2c_adapter *adap, int addr)
+{
+        struct mb862xxfb_par *par = adap->algo_data;
+
+        outreg(i2c, GC_I2C_DAR, addr);
+        outreg(i2c, GC_I2C_CCR, I2C_CLOCK_AND_ENABLE);
+        outreg(i2c, GC_I2C_BCR, par->i2c_rs ? I2C_REPEATED_START : I2C_START);
+        if (!mb862xx_i2c_wait_event(adap))
+                return -EIO;
+        par->i2c_rs = !(inreg(i2c, GC_I2C_BSR) & I2C_LRB);
+        return par->i2c_rs;
+}
+
+static int mb862xx_i2c_write_byte(struct i2c_adapter *adap, u8 byte)
+{
+        struct mb862xxfb_par *par = adap->algo_data;
+
+        outreg(i2c, GC_I2C_DAR, byte);
+        outreg(i2c, GC_I2C_BCR, I2C_START);
+        if (!mb862xx_i2c_wait_event(adap))
+                return -EIO;
+        return !(inreg(i2c, GC_I2C_BSR) & I2C_LRB);
+}
+
+static int mb862xx_i2c_read_byte(struct i2c_adapter *adap, u8 *byte, int last)
+{
+        struct mb862xxfb_par *par = adap->algo_data;
+
+        outreg(i2c, GC_I2C_BCR, I2C_START | (last ? 0 : I2C_ACK));
+        if (!mb862xx_i2c_wait_event(adap))
+                return 0;
+        *byte = inreg(i2c, GC_I2C_DAR);
+        return 1;
+}
+
+void mb862xx_i2c_stop(struct i2c_adapter *adap)
+{
+        struct mb862xxfb_par *par = adap->algo_data;
+
+        outreg(i2c, GC_I2C_BCR, I2C_STOP);
+        outreg(i2c, GC_I2C_CCR, I2C_DISABLE);
+        par->i2c_rs = 0;
+}
+
+static int mb862xx_i2c_read(struct i2c_adapter *adap, struct i2c_msg *m)
+{
+        int i, ret = 0;
+        int last = m->len - 1;
+
+        for (i = 0; i < m->len; i++) {
+                if (!mb862xx_i2c_read_byte(adap, &m->buf[i], i == last)) {
+                        ret = -EIO;
+                        break;
+                }
+        }
+        return ret;
+}
+
+static int mb862xx_i2c_write(struct i2c_adapter *adap, struct i2c_msg *m)
+{
+        int i, ret = 0;
+
+        for (i = 0; i < m->len; i++) {
+                if (!mb862xx_i2c_write_byte(adap, m->buf[i])) {
+                        ret = -EIO;
+                        break;
+                }
+        }
+        return ret;
+}
+
+static int mb862xx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+                        int num)
+{
+        struct mb862xxfb_par *par = adap->algo_data;
+        struct i2c_msg *m;
+        int addr;
+        int i = 0, err = 0;
+
+        dev_dbg(par->dev, "%s: %d msgs\n", __func__, num);
+
+        for (i = 0; i < num; i++) {
+                m = &msgs[i];
+                if (!m->len) {
+                        dev_dbg(par->dev, "%s: null msgs\n", __func__);
+                        continue;
+                }
+                addr = m->addr;
+                if (m->flags & I2C_M_RD)
+                        addr |= 1;
+
+                err = mb862xx_i2c_do_address(adap, addr);
+                if (err < 0)
+                        break;
+                if (m->flags & I2C_M_RD)
+                        err = mb862xx_i2c_read(adap, m);
+                else
+                        err = mb862xx_i2c_write(adap, m);
+        }
+
+        if (i)
+                mb862xx_i2c_stop(adap);
+
+        return (err < 0) ? err : i;
+}
+
+static u32 mb862xx_func(struct i2c_adapter *adap)
+{
+        return I2C_FUNC_SMBUS_BYTE_DATA;
+}
+
+static const struct i2c_algorithm mb862xx_algo = {
+        .master_xfer    = mb862xx_xfer,
+        .functionality  = mb862xx_func,
+};
+
+static struct i2c_adapter mb862xx_i2c_adapter = {
+        .name           = "MB862xx I2C adapter",
+        .algo           = &mb862xx_algo,
+        .owner          = THIS_MODULE,
+};
+
+int mb862xx_i2c_init(struct mb862xxfb_par *par)
+{
+        int ret;
+
+        mb862xx_i2c_adapter.algo_data = par;
+        par->adap = &mb862xx_i2c_adapter;
+
+        ret = i2c_add_adapter(par->adap);
+        if (ret < 0) {
+                dev_err(par->dev, "failed to add %s\n",
+                        mb862xx_i2c_adapter.name);
+        }
+        return ret;
+}
+
+void mb862xx_i2c_exit(struct mb862xxfb_par *par)
+{
+        if (par->adap) {
+                i2c_del_adapter(par->adap);
+                par->adap = NULL;
+        }
+}
diff --git a/drivers/video/mb862xx/mb862xx_reg.h b/drivers/video/mb862xx/mb862xx_reg.h
index 737fc011caff..5784b018f15d 100644
--- a/drivers/video/mb862xx/mb862xx_reg.h
+++ b/drivers/video/mb862xx/mb862xx_reg.h
@@ -80,6 +80,27 @@
 
 #define GC_DISP_REFCLK_400      400
 
+/* I2C */
+#define GC_I2C_BSR              0x00000000      /* BSR */
+#define GC_I2C_BCR              0x00000004      /* BCR */
+#define GC_I2C_CCR              0x00000008      /* CCR */
+#define GC_I2C_ADR              0x0000000C      /* ADR */
+#define GC_I2C_DAR              0x00000010      /* DAR */
+
+#define I2C_DISABLE             0x00000000
+#define I2C_STOP                0x00000000
+#define I2C_START               0x00000010
+#define I2C_REPEATED_START      0x00000030
+#define I2C_CLOCK_AND_ENABLE    0x0000003f
+#define I2C_READY               0x01
+#define I2C_INT                 0x01
+#define I2C_INTE                0x02
+#define I2C_ACK                 0x08
+#define I2C_BER                 0x80
+#define I2C_BEIE                0x40
+#define I2C_TRX                 0x80
+#define I2C_LRB                 0x10
+
 /* Carmine specific */
 #define MB86297_DRAW_BASE               0x00020000
 #define MB86297_DISP0_BASE              0x00100000
diff --git a/drivers/video/mb862xx/mb862xxfb.h b/drivers/video/mb862xx/mb862xxfb.h
index d7e7cb76bbf2..d5dd7d9ec0cd 100644
--- a/drivers/video/mb862xx/mb862xxfb.h
+++ b/drivers/video/mb862xx/mb862xxfb.h
@@ -57,11 +57,20 @@ struct mb862xxfb_par {
         unsigned int            refclk;         /* disp. reference clock */
         struct mb862xx_gc_mode  *gc_mode;       /* GDC mode init data */
         int                     pre_init;       /* don't init display if 1 */
+        struct i2c_adapter      *adap;          /* GDC I2C bus adapter */
+        int                     i2c_rs;
 
         u32                     pseudo_palette[16];
 };
 
 extern void mb862xxfb_init_accel(struct fb_info *info, int xres);
+#ifdef CONFIG_FB_MB862XX_I2C
+extern int mb862xx_i2c_init(struct mb862xxfb_par *par);
+extern void mb862xx_i2c_exit(struct mb862xxfb_par *par);
+#else
+static inline int mb862xx_i2c_init(struct mb862xxfb_par *par) { return 0; }
+static inline void mb862xx_i2c_exit(struct mb862xxfb_par *par) { }
+#endif
 
 #if defined(CONFIG_FB_MB862XX_LIME) && defined(CONFIG_FB_MB862XX_PCI_GDC)
 #error  "Select Lime GDC or CoralP/Carmine support, but not both together"
diff --git a/drivers/video/mb862xx/mb862xxfb.c b/drivers/video/mb862xx/mb862xxfbdrv.c
index ffb6a2c36d3c..0cc20b4fbcb5 100644
--- a/drivers/video/mb862xx/mb862xxfb.c
+++ b/drivers/video/mb862xx/mb862xxfbdrv.c
@@ -772,6 +772,8 @@ static int coralp_init(struct mb862xxfb_par *par)
         } else {
                 return -ENODEV;
         }
+
+        mb862xx_i2c_init(par);
         return 0;
 }
 
@@ -1029,6 +1031,8 @@ static void __devexit mb862xx_pci_remove(struct pci_dev *pdev)
                 outreg(host, GC_IMASK, 0);
         }
 
+        mb862xx_i2c_exit(par);
+
         device_remove_file(&pdev->dev, &dev_attr_dispregs);
 
         pci_set_drvdata(pdev, NULL);