[ARM] orion: add hwrng timeriomem hook to TS-78xx

Add hook so that the HW RNG source on the TS-78xx is available.
Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Nicolas Pitre <nico@marvell.com>

arch/arm/configs/orion5x_defconfig

@@ -903,7 +903,8 @@ CONFIG_UNIX98_PTYS=y
 CONFIG_LEGACY_PTYS=y
 CONFIG_LEGACY_PTY_COUNT=16
 # CONFIG_IPMI_HANDLER is not set
-# CONFIG_HW_RANDOM is not set
+CONFIG_HW_RANDOM=m
+CONFIG_HW_RANDOM_TIMERIOMEM=m
 # CONFIG_R3964 is not set
 # CONFIG_APPLICOM is not set
 # CONFIG_RAW_DRIVER is not set

arch/arm/mach-orion5x/ts78xx-fpga.h

@@ -25,6 +25,7 @@ struct fpga_devices {
 	/* Technologic Systems */
 	struct fpga_device 	ts_rtc;
 	struct fpga_device 	ts_nand;
+	struct fpga_device 	ts_rng;
 };
 
 struct ts78xx_fpga_data {

arch/arm/mach-orion5x/ts78xx-setup.c

@@ -17,6 +17,7 @@
 #include <linux/m48t86.h>
 #include <linux/mtd/nand.h>
 #include <linux/mtd/partitions.h>
+#include <linux/timeriomem-rng.h>
 #include <asm/mach-types.h>
 #include <asm/mach/arch.h>
 #include <asm/mach/map.h>
@@ -269,6 +270,50 @@ static void ts78xx_ts_nand_unload(void)
 	platform_device_del(&ts78xx_ts_nand_device);
 }
 
+/*****************************************************************************
+ * HW RNG
+ ****************************************************************************/
+#define TS_RNG_DATA	(TS78XX_FPGA_REGS_PHYS_BASE | 0x044)
+
+static struct resource ts78xx_ts_rng_resource = {
+	.flags		= IORESOURCE_MEM,
+	.start		= TS_RNG_DATA,
+	.end		= TS_RNG_DATA + 4 - 1,
+};
+
+static struct timeriomem_rng_data ts78xx_ts_rng_data = {
+	.period		= 1000000, /* one second */
+};
+
+static struct platform_device ts78xx_ts_rng_device = {
+	.name		= "timeriomem_rng",
+	.id		= -1,
+	.dev		= {
+		.platform_data	= &ts78xx_ts_rng_data,
+	},
+	.resource	= &ts78xx_ts_rng_resource,
+	.num_resources	= 1,
+};
+
+static int ts78xx_ts_rng_load(void)
+{
+	int rc;
+
+	if (ts78xx_fpga.supports.ts_rng.init == 0) {
+		rc = platform_device_register(&ts78xx_ts_rng_device);
+		if (!rc)
+			ts78xx_fpga.supports.ts_rng.init = 1;
+	} else
+		rc = platform_device_add(&ts78xx_ts_rng_device);
+
+	return rc;
+};
+
+static void ts78xx_ts_rng_unload(void)
+{
+	platform_device_del(&ts78xx_ts_rng_device);
+}
+
 /*****************************************************************************
  * FPGA 'hotplug' support code
  ****************************************************************************/
@@ -276,6 +321,7 @@ static void ts78xx_fpga_devices_zero_init(void)
 {
 	ts78xx_fpga.supports.ts_rtc.init = 0;
 	ts78xx_fpga.supports.ts_nand.init = 0;
+	ts78xx_fpga.supports.ts_rng.init = 0;
 }
 
 static void ts78xx_fpga_supports(void)
@@ -289,10 +335,12 @@ static void ts78xx_fpga_supports(void)
 	case TS7800_REV_5:
 		ts78xx_fpga.supports.ts_rtc.present = 1;
 		ts78xx_fpga.supports.ts_nand.present = 1;
+		ts78xx_fpga.supports.ts_rng.present = 1;
 		break;
 	default:
 		ts78xx_fpga.supports.ts_rtc.present = 0;
 		ts78xx_fpga.supports.ts_nand.present = 0;
+		ts78xx_fpga.supports.ts_rng.present = 0;
 	}
 }
 
@@ -316,6 +364,14 @@ static int ts78xx_fpga_load_devices(void)
 		}
 		ret |= tmp;
 	}
+	if (ts78xx_fpga.supports.ts_rng.present == 1) {
+		tmp = ts78xx_ts_rng_load();
+		if (tmp) {
+			printk(KERN_INFO "TS-78xx: RNG not registered\n");
+			ts78xx_fpga.supports.ts_rng.present = 0;
+		}
+		ret |= tmp;
+	}
 
 	return ret;
 }
@@ -328,6 +384,8 @@ static int ts78xx_fpga_unload_devices(void)
 		ts78xx_ts_rtc_unload();
 	if (ts78xx_fpga.supports.ts_nand.present == 1)
 		ts78xx_ts_nand_unload();
+	if (ts78xx_fpga.supports.ts_rng.present == 1)
+		ts78xx_ts_rng_unload();
 
 	return ret;
 }