(+ Andre)
Hi,
On 03/06/2020 23:31, Stefano Stabellini wrote:
Touching the watchdog is required to be able to reboot the board.
In general the preferred method is PSCI. Does it mean RPI 4 doesn't
support PSCI at all?
The implementation is based on
drivers/watchdog/bcm2835_wdt.c:__bcm2835_restart in Linux.
Can you give the baseline? This would allow us to track an issue and
port them.
Signed-off-by: Stefano Stabellini <stefano.stabell...@xilinx.com>
---
xen/arch/arm/platforms/brcm-raspberry-pi.c | 60 ++++++++++++++++++++++
1 file changed, 60 insertions(+)
diff --git a/xen/arch/arm/platforms/brcm-raspberry-pi.c
b/xen/arch/arm/platforms/brcm-raspberry-pi.c
index f5ae58a7d5..0214ae2b3c 100644
--- a/xen/arch/arm/platforms/brcm-raspberry-pi.c
+++ b/xen/arch/arm/platforms/brcm-raspberry-pi.c
@@ -18,6 +18,10 @@
*/
#include <asm/platform.h>
+#include <xen/delay.h>
+#include <xen/mm.h>
+#include <xen/vmap.h>
+#include <asm/io.h>
We are trying to keep the headers ordered alphabetically within each
directory and then 'xen/' first following by 'asm/'.
static const char *const rpi4_dt_compat[] __initconst =
{
@@ -37,12 +41,68 @@ static const struct dt_device_match rpi4_blacklist_dev[]
__initconst =
* The aux peripheral also shares a page with the aux UART.
*/
DT_MATCH_COMPATIBLE("brcm,bcm2835-aux"),
+ /* Special device used for rebooting */
+ DT_MATCH_COMPATIBLE("brcm,bcm2835-pm"),
{ /* sentinel */ },
};
+
+#define PM_PASSWORD 0x5a000000
+#define PM_RSTC 0x1c
+#define PM_WDOG 0x24
+#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
+#define PM_RSTC_WRCFG_CLR 0xffffffcf
NIT: It is a bit odd you introduce the 5 define together but the first 3
have a different indentation compare to the last 2.
+
+static void __iomem *rpi4_map_watchdog(void)
+{
+ void __iomem *base;
+ struct dt_device_node *node;
+ paddr_t start, len;
+ int ret;
+
+ node = dt_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm");
+ if ( !node )
+ return NULL;
+
+ ret = dt_device_get_address(node, 0, &start, &len);
+ if ( ret )
+ {
+ dprintk(XENLOG_ERR, "Cannot read watchdog register address\n");
I would suggest to use printk() rather than dprintk. It would be useful
for a normal user to know that we didn't manage to reset the platform
and why.
+ return NULL;
+ }
+
+ base = ioremap_nocache(start & PAGE_MASK, PAGE_SIZE);
+ if ( !base )
+ {
+ dprintk(XENLOG_ERR, "Unable to map watchdog register!\n");
+ return NULL;
+ }
+
+ return base;
+}
+
+static void rpi4_reset(void)
+{
+ u32 val;
We are trying to get rid of any use of u32 in Xen code (the coding style
used in this file). Please use uint32_t instead.
+ void __iomem *base = rpi4_map_watchdog();
Newline here please.
+ if ( !base )
+ return;
+
+ /* use a timeout of 10 ticks (~150us) */
+ writel(10 | PM_PASSWORD, base + PM_WDOG);
+ val = readl(base + PM_RSTC);
+ val &= PM_RSTC_WRCFG_CLR;
+ val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
+ writel(val, base + PM_RSTC);
+
+ /* No sleeping, possibly atomic. */
+ mdelay(1);
+}
+
PLATFORM_START(rpi4, "Raspberry Pi 4")
.compatible = rpi4_dt_compat,
.blacklist_dev = rpi4_blacklist_dev,
+ .reset = rpi4_reset,
.dma_bitsize = 30,
PLATFORM_END
Cheers,
--
Julien Grall
