firmware-zynqmp: export functions for setting GGS/PGGS

The ZynqMP features eight 32-bit global storage registers that are available
for general use. Four of them have their values preserved after software
reboots and four are cleared on software reboots.

Import the Linux API used to read and write these registers.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20230913132456.2211919-3-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 66 insertions, 0 deletions

diff --git a/arch/arm/mach-zynqmp/firmware-zynqmp.c b/arch/arm/mach-zynqmp/firmware-zynqmp.c
index 128f042ddc..8d06c65b0e 100644
--- a/arch/arm/mach-zynqmp/firmware-zynqmp.c
+++ b/arch/arm/mach-zynqmp/firmware-zynqmp.c
@@ -503,6 +503,72 @@ static int zynqmp_pm_ioctl(u32 node_id, u32 ioctl_id, u32 arg1, u32 arg2,
 				   arg1, arg2, out);
 }
 
+/*
+ * zynqmp_pm_write_ggs() - PM API for writing global general storage (ggs)
+ * @index:	GGS register index
+ * @value:	Register value to be written
+ *
+ * This function writes value to GGS register.
+ *
+ * Return:      Returns status, either success or error+reason
+ */
+int zynqmp_pm_write_ggs(u32 index, u32 value)
+{
+	return zynqmp_pm_invoke_fn(PM_IOCTL, 0, IOCTL_WRITE_GGS,
+				   index, value, NULL);
+}
+EXPORT_SYMBOL_GPL(zynqmp_pm_write_ggs);
+
+/**
+ * zynqmp_pm_read_ggs() - PM API for reading global general storage (ggs)
+ * @index:	GGS register index
+ * @value:	Register value to be written
+ *
+ * This function returns GGS register value.
+ *
+ * Return:	Returns status, either success or error+reason
+ */
+int zynqmp_pm_read_ggs(u32 index, u32 *value)
+{
+	return zynqmp_pm_invoke_fn(PM_IOCTL, 0, IOCTL_READ_GGS,
+				   index, 0, value);
+}
+EXPORT_SYMBOL_GPL(zynqmp_pm_read_ggs);
+
+/**
+ * zynqmp_pm_write_pggs() - PM API for writing persistent global general
+ *			     storage (pggs)
+ * @index:	PGGS register index
+ * @value:	Register value to be written
+ *
+ * This function writes value to PGGS register.
+ *
+ * Return:	Returns status, either success or error+reason
+ */
+int zynqmp_pm_write_pggs(u32 index, u32 value)
+{
+	return zynqmp_pm_invoke_fn(PM_IOCTL, 0, IOCTL_WRITE_PGGS, index, value,
+				   NULL);
+}
+EXPORT_SYMBOL_GPL(zynqmp_pm_write_pggs);
+
+/**
+ * zynqmp_pm_read_pggs() - PM API for reading persistent global general
+ *			     storage (pggs)
+ * @index:	PGGS register index
+ * @value:	Register value to be written
+ *
+ * This function returns PGGS register value.
+ *
+ * Return:	Returns status, either success or error+reason
+ */
+int zynqmp_pm_read_pggs(u32 index, u32 *value)
+{
+	return zynqmp_pm_invoke_fn(PM_IOCTL, 0, IOCTL_READ_PGGS, index, 0,
+				   value);
+}
+EXPORT_SYMBOL_GPL(zynqmp_pm_read_pggs);
+
 /**
  * zynqmp_pm_fpga_load - Perform the fpga load
  * @address:	Address to write to