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authorGeert Uytterhoeven <geert@linux-m68k.org>2021-01-19 09:09:38 +0100
committerStafford Horne <shorne@gmail.com>2021-01-21 21:40:05 +0900
commit3706f9f76a4f79f8e7b2eb8b99877e89fe9ad732 (patch)
tree0f49092346593f9122b28e47222347ee8118f6cc /drivers/soc/litex
parent803c72c8547c56917331057bff55703baeb59e8e (diff)
drivers/soc/litex: Add restart handler
Let the LiteX SoC Controller register a restart handler, which resets the LiteX SoC by writing 1 to CSR_CTRL_RESET_ADDR. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Joel Stanley <joel@jms.id.au> Signed-off-by: Stafford Horne <shorne@gmail.com>
Diffstat (limited to 'drivers/soc/litex')
-rw-r--r--drivers/soc/litex/litex_soc_ctrl.c42
1 files changed, 41 insertions, 1 deletions
diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c
index da17ba56b795..a7dd5be9fd5b 100644
--- a/drivers/soc/litex/litex_soc_ctrl.c
+++ b/drivers/soc/litex/litex_soc_ctrl.c
@@ -15,6 +15,11 @@
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/io.h>
+#include <linux/reboot.h>
+
+/* reset register located at the base address */
+#define RESET_REG_OFF 0x00
+#define RESET_REG_VALUE 0x00000001
#define SCRATCH_REG_OFF 0x04
#define SCRATCH_REG_VALUE 0x12345678
@@ -66,8 +71,19 @@ static int litex_check_csr_access(void __iomem *reg_addr)
struct litex_soc_ctrl_device {
void __iomem *base;
+ struct notifier_block reset_nb;
};
+static int litex_reset_handler(struct notifier_block *this, unsigned long mode,
+ void *cmd)
+{
+ struct litex_soc_ctrl_device *soc_ctrl_dev =
+ container_of(this, struct litex_soc_ctrl_device, reset_nb);
+
+ litex_write32(soc_ctrl_dev->base + RESET_REG_OFF, RESET_REG_VALUE);
+ return NOTIFY_DONE;
+}
+
static const struct of_device_id litex_soc_ctrl_of_match[] = {
{.compatible = "litex,soc-controller"},
{},
@@ -78,6 +94,7 @@ MODULE_DEVICE_TABLE(of, litex_soc_ctrl_of_match);
static int litex_soc_ctrl_probe(struct platform_device *pdev)
{
struct litex_soc_ctrl_device *soc_ctrl_dev;
+ int error;
soc_ctrl_dev = devm_kzalloc(&pdev->dev, sizeof(*soc_ctrl_dev), GFP_KERNEL);
if (!soc_ctrl_dev)
@@ -87,7 +104,29 @@ static int litex_soc_ctrl_probe(struct platform_device *pdev)
if (IS_ERR(soc_ctrl_dev->base))
return PTR_ERR(soc_ctrl_dev->base);
- return litex_check_csr_access(soc_ctrl_dev->base);
+ error = litex_check_csr_access(soc_ctrl_dev->base);
+ if (error)
+ return error;
+
+ platform_set_drvdata(pdev, soc_ctrl_dev);
+
+ soc_ctrl_dev->reset_nb.notifier_call = litex_reset_handler;
+ soc_ctrl_dev->reset_nb.priority = 128;
+ error = register_restart_handler(&soc_ctrl_dev->reset_nb);
+ if (error) {
+ dev_warn(&pdev->dev, "cannot register restart handler: %d\n",
+ error);
+ }
+
+ return 0;
+}
+
+static int litex_soc_ctrl_remove(struct platform_device *pdev)
+{
+ struct litex_soc_ctrl_device *soc_ctrl_dev = platform_get_drvdata(pdev);
+
+ unregister_restart_handler(&soc_ctrl_dev->reset_nb);
+ return 0;
}
static struct platform_driver litex_soc_ctrl_driver = {
@@ -96,6 +135,7 @@ static struct platform_driver litex_soc_ctrl_driver = {
.of_match_table = of_match_ptr(litex_soc_ctrl_of_match)
},
.probe = litex_soc_ctrl_probe,
+ .remove = litex_soc_ctrl_remove,
};
module_platform_driver(litex_soc_ctrl_driver);