arm: socfpga: Changed to store QSPI reference clock in kHz

Changed to store QSPI reference clock in kHz instead of Hz in
boot scratch cold0 register for Stratix10 and Agilex.

This patch is in preparation for Intel N5X SDRAM driver
support. Reserved 4 bits for Intel N5X SDRAM driver,
and there will be 28 bits to store QSPI reference clock.
Due to limited bits, QSPI reference clock frequency is
converted to kHz from Hz.

Signed-off-by: Siew Chin Lim <elly.siew.chin.lim@intel.com>
Signed-off-by: Tien Fong Chee <tien.fong.chee@intel.com>

1 files changed, 30 insertions, 2 deletions

diff --git a/arch/arm/mach-socfpga/clock_manager.c b/arch/arm/mach-socfpga/clock_manager.c
index be426a5cfb8..9e645a42531 100644
--- a/arch/arm/mach-socfpga/clock_manager.c
+++ b/arch/arm/mach-socfpga/clock_manager.c
@@ -65,10 +65,38 @@ int set_cpu_clk_info(void)
 }
 
 #if IS_ENABLED(CONFIG_TARGET_SOCFPGA_SOC64)
+int cm_set_qspi_controller_clk_hz(u32 clk_hz)
+{
+	u32 reg;
+	u32 clk_khz;
+
+	/*
+	 * Store QSPI ref clock and set into sysmgr boot register.
+	 * Only clock freq in kHz degree is accepted due to limited bits[27:0]
+	 * is reserved for storing the QSPI clock freq into boot scratch cold0
+	 * register.
+	 */
+	if (clk_hz < 1000)
+		return -EINVAL;
+
+	clk_khz = clk_hz / 1000;
+	printf("QSPI: Reference clock at %d kHz\n", clk_khz);
+
+	reg = (readl(socfpga_get_sysmgr_addr() +
+		     SYSMGR_SOC64_BOOT_SCRATCH_COLD0)) &
+		     ~(SYSMGR_SCRATCH_REG_0_QSPI_REFCLK_MASK);
+
+	writel((clk_khz & SYSMGR_SCRATCH_REG_0_QSPI_REFCLK_MASK) | reg,
+	       socfpga_get_sysmgr_addr() + SYSMGR_SOC64_BOOT_SCRATCH_COLD0);
+
+	return 0;
+}
+
 unsigned int cm_get_qspi_controller_clk_hz(void)
 {
-	return readl(socfpga_get_sysmgr_addr() +
-		     SYSMGR_SOC64_BOOT_SCRATCH_COLD0);
+	return (readl(socfpga_get_sysmgr_addr() +
+		     SYSMGR_SOC64_BOOT_SCRATCH_COLD0) &
+		     SYSMGR_SCRATCH_REG_0_QSPI_REFCLK_MASK) * 1000;
 }
 #endif