Add a function to set the tap delay for the clk phase of the sd host
controller.
Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
Reviewed-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
---
arch/arm/mach-zynqmp/firmware-zynqmp.c | 42 ++++++++++++++++++++++++++++++++++
include/mach/zynqmp/firmware-zynqmp.h | 23 +++++++++++++++++++
2 files changed, 65 insertions(+)
diff --git a/arch/arm/mach-zynqmp/firmware-zynqmp.c b/arch/arm/mach-zynqmp/firmware-zynqmp.c
index b383ed6f00..039a46e767 100644
--- a/arch/arm/mach-zynqmp/firmware-zynqmp.c
+++ b/arch/arm/mach-zynqmp/firmware-zynqmp.c
@@ -48,6 +48,7 @@ enum pm_ret_status {
enum pm_api_id {
PM_GET_API_VERSION = 1,
+ PM_MMIO_WRITE = 19,
PM_FPGA_LOAD = 22,
PM_FPGA_GET_STATUS,
PM_IOCTL = 34,
@@ -511,6 +512,47 @@ static int zynqmp_pm_ioctl(u32 node_id, u32 ioctl_id, u32 arg1, u32 arg2,
arg1, arg2, out);
}
+/**
+ * zynqmp_pm_set_sd_tapdelay() - Set tap delay for the SD device
+ *
+ * @node_id: Node ID of the device
+ * @type: Type of tap delay to set (input/output)
+ * @value: Value to set fot the tap delay
+ *
+ * This function sets input/output tap delay for the SD device.
+ *
+ * Return: Returns status, either success or error+reason
+ */
+int zynqmp_pm_set_sd_tapdelay(u32 node_id, u32 type, u32 value)
+{
+ u32 reg = (type == PM_TAPDELAY_INPUT) ? SD_ITAPDLY : SD_OTAPDLYSEL;
+ u32 mask = (node_id == NODE_SD_0) ? GENMASK(15, 0) : GENMASK(31, 16);
+
+ if (value) {
+ return zynqmp_pm_invoke_fn(PM_IOCTL, node_id,
+ IOCTL_SET_SD_TAPDELAY,
+ type, value, NULL);
+ }
+
+ /*
+ * Work around completely misdesigned firmware API on Xilinx ZynqMP.
+ * The IOCTL_SET_SD_TAPDELAY firmware call allows the caller to only
+ * ever set IOU_SLCR SD_ITAPDLY Register SD0_ITAPDLYENA/SD1_ITAPDLYENA
+ * bits, but there is no matching call to clear those bits. If those
+ * bits are not cleared, SDMMC tuning may fail.
+ *
+ * Luckily, there are PM_MMIO_READ/PM_MMIO_WRITE calls which seem to
+ * allow complete unrestricted access to all address space, including
+ * IOU_SLCR SD_ITAPDLY Register and all the other registers, access
+ * to which was supposed to be protected by the current firmware API.
+ *
+ * Use PM_MMIO_READ/PM_MMIO_WRITE to re-implement the missing counter
+ * part of IOCTL_SET_SD_TAPDELAY which clears SDx_ITAPDLYENA bits.
+ */
+ return zynqmp_pm_invoke_fn(PM_MMIO_WRITE, reg, mask, 0, 0, NULL);
+}
+EXPORT_SYMBOL_GPL(zynqmp_pm_set_sd_tapdelay);
+
/**
* zynqmp_pm_sd_dll_reset() - Reset DLL logic
*
diff --git a/include/mach/zynqmp/firmware-zynqmp.h b/include/mach/zynqmp/firmware-zynqmp.h
index 630677285f..00c63058f4 100644
--- a/include/mach/zynqmp/firmware-zynqmp.h
+++ b/include/mach/zynqmp/firmware-zynqmp.h
@@ -27,6 +27,10 @@
#define ZYNQMP_PCAP_STATUS_FPGA_DONE BIT(3)
+/* ZynqMP SD tap delay tuning */
+#define SD_ITAPDLY 0xFF180314
+#define SD_OTAPDLYSEL 0xFF180318
+
enum pm_ioctl_id {
IOCTL_GET_RPU_OPER_MODE = 0,
IOCTL_SET_RPU_OPER_MODE = 1,
@@ -80,6 +84,22 @@ struct zynqmp_pm_query_data {
u32 arg3;
};
+enum pm_node_id {
+ NODE_SD_0 = 39,
+ NODE_SD_1 = 40,
+};
+
+enum tap_delay_type {
+ PM_TAPDELAY_INPUT = 0,
+ PM_TAPDELAY_OUTPUT = 1,
+};
+
+enum dll_reset_type {
+ PM_DLL_RESET_ASSERT = 0,
+ PM_DLL_RESET_RELEASE = 1,
+ PM_DLL_RESET_PULSE = 2,
+};
+
struct zynqmp_eemi_ops {
int (*get_api_version)(u32 *version);
int (*query_data)(struct zynqmp_pm_query_data qdata, u32 *out);
@@ -99,6 +119,9 @@ struct zynqmp_eemi_ops {
const struct zynqmp_eemi_ops *zynqmp_pm_get_eemi_ops(void);
+int zynqmp_pm_set_sd_tapdelay(u32 node_id, u32 type, u32 value);
+int zynqmp_pm_sd_dll_reset(u32 node_id, u32 type);
+
int zynqmp_pm_write_ggs(u32 index, u32 value);
int zynqmp_pm_read_ggs(u32 index, u32 *value);
int zynqmp_pm_write_pggs(u32 index, u32 value);
--
2.40.1
