gdsys: mpc8308: Use shadow register for output GPIO values

Since the gpio output status on MPC8xxx cannot be read back, it has to
be buffered locally.
Signed-off-by: NDirk Eibach <dirk.eibach@gdsys.cc>
Signed-off-by: NMario Six <mario.six@gdsys.cc>

board/gdsys/mpc8308/hrcon.c

@@ -287,8 +287,8 @@ void mpc8308_setup_hw(void)
 	/*
 	 * set "startup-finished"-gpios
 	 */
-	setbits_be32(&immr->gpio[0].dir, (BIT(31 - 11) | BIT(31 - 12)));
-	setbits_be32(&immr->gpio[0].dat, BIT(31 - 12));
+	setbits_be32(&immr->gpio[0].dir, BIT(31 - 11) | BIT(31 - 12));
+	setbits_gpio0_out(BIT(31 - 12));
 }
 
 int mpc8308_get_fpga_done(uint fpga)

board/gdsys/mpc8308/mpc8308.c

@@ -24,6 +24,25 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+/* as gpio output status cannot be read back, we have to buffer it locally */
+u32 gpio0_out;
+
+void setbits_gpio0_out(u32 mask)
+{
+	immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
+
+	gpio0_out |= mask;
+	out_be32(&immr->gpio[0].dat, gpio0_out);
+}
+
+void clrbits_gpio0_out(u32 mask)
+{
+	immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
+
+	gpio0_out &= ~mask;
+	out_be32(&immr->gpio[0].dat, gpio0_out);
+}
+
 int get_fpga_state(uint dev)
 {
 	return gd->arch.fpga_state[dev];

board/gdsys/mpc8308/mpc8308.h

 #ifndef __MPC8308_H_
 #define __MPC8308_H_
 
+void setbits_gpio0_out(u32 mask);
+void clrbits_gpio0_out(u32 mask);
+
 /* functions to be provided by board implementation */
 void mpc8308_init(void);
 void mpc8308_set_fpga_reset(unsigned state);

board/gdsys/mpc8308/strider.c

@@ -343,7 +343,7 @@ void mpc8308_setup_hw(void)
 	 * set "startup-finished"-gpios
 	 */
 	setbits_be32(&immr->gpio[0].dir, BIT(31 - 11) | BIT(31 - 12));
-	setbits_be32(&immr->gpio[0].dat, BIT(31 - 12));
+	setbits_gpio0_out(BIT(31 - 12));
 }
 
 int mpc8308_get_fpga_done(uint fpga)