rtc: powerpc: provide rtc_class_ops directly

The rtc-generic driver provides an architecture specific
wrapper on top of the generic rtc_class_ops abstraction,
and powerpc has another abstraction on top, which is a bit
silly.

This changes the powerpc rtc-generic device to provide its
rtc_class_ops directly, to reduce the number of layers
by one.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

arch/powerpc/kernel/time.c

@@ -56,6 +56,7 @@
 #include <linux/irq_work.h>
 #include <linux/clk-provider.h>
 #include <linux/suspend.h>
+#include <linux/rtc.h>
 #include <asm/trace.h>
 
 #include <asm/io.h>
@@ -1081,16 +1082,42 @@ void calibrate_delay(void)
 	loops_per_jiffy = tb_ticks_per_jiffy;
 }
 
+#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
+static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
+{
+	ppc_md.get_rtc_time(tm);
+	return rtc_valid_tm(tm);
+}
+
+static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
+{
+	if (!ppc_md.set_rtc_time)
+		return -EOPNOTSUPP;
+
+	if (ppc_md.set_rtc_time(tm) < 0)
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static const struct rtc_class_ops rtc_generic_ops = {
+	.read_time = rtc_generic_get_time,
+	.set_time = rtc_generic_set_time,
+};
+
 static int __init rtc_init(void)
 {
 	struct platform_device *pdev;
 
 	if (!ppc_md.get_rtc_time)
 		return -ENODEV;
 
-	pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
+	pdev = platform_device_register_data(NULL, "rtc-generic", -1,
+					     &rtc_generic_ops,
+					     sizeof(rtc_generic_ops));
 
 	return PTR_ERR_OR_ZERO(pdev);
 }
 
 device_initcall(rtc_init);
+#endif

drivers/rtc/rtc-generic.c

@@ -9,7 +9,7 @@
 #include <linux/platform_device.h>
 #include <linux/rtc.h>
 
-#if defined(CONFIG_PPC)
+#if 0
 #include <asm/rtc.h>
 
 static int generic_get_time(struct device *dev, struct rtc_time *tm)