mips: octeon: Add cvmx-helper-jtag.c

Import cvmx-helper-jtag.c from 2013 U-Boot. It will be used by the later
added drivers to support PCIe and networking on the MIPS Octeon II / III
platforms.

Signed-off-by: Aaron Williams <awilliams@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>

arch/mips/mach-octeon/cvmx-helper-jtag.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Marvell International Ltd.
+ *
+ * Helper utilities for qlm_jtag.
+ */
+
+#include <log.h>
+#include <asm/global_data.h>
+#include <linux/delay.h>
+
+#include <mach/cvmx-regs.h>
+#include <mach/octeon-model.h>
+#include <mach/cvmx-fuse.h>
+#include <mach/octeon-feature.h>
+#include <mach/cvmx-qlm.h>
+#include <mach/octeon_qlm.h>
+#include <mach/cvmx-pcie.h>
+#include <mach/cvmx-ciu-defs.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * Initialize the internal QLM JTAG logic to allow programming
+ * of the JTAG chain by the cvmx_helper_qlm_jtag_*() functions.
+ * These functions should only be used at the direction of Cavium
+ * Networks. Programming incorrect values into the JTAG chain
+ * can cause chip damage.
+ */
+void cvmx_helper_qlm_jtag_init(void)
+{
+	union cvmx_ciu_qlm_jtgc jtgc;
+	int clock_div = 0;
+	int divisor;
+
+	divisor = gd->bus_clk / (1000000 * (OCTEON_IS_MODEL(OCTEON_CN68XX) ? 10 : 25));
+
+	divisor = (divisor - 1) >> 2;
+	/* Convert the divisor into a power of 2 shift */
+	while (divisor) {
+		clock_div++;
+		divisor >>= 1;
+	}
+
+	/*
+	 * Clock divider for QLM JTAG operations.  sclk is divided by
+	 * 2^(CLK_DIV + 2)
+	 */
+	jtgc.u64 = 0;
+	jtgc.s.clk_div = clock_div;
+	jtgc.s.mux_sel = 0;
+	if (OCTEON_IS_MODEL(OCTEON_CN63XX) || OCTEON_IS_MODEL(OCTEON_CN66XX))
+		jtgc.s.bypass = 0x7;
+	else
+		jtgc.s.bypass = 0xf;
+	if (OCTEON_IS_MODEL(OCTEON_CN68XX))
+		jtgc.s.bypass_ext = 1;
+	csr_wr(CVMX_CIU_QLM_JTGC, jtgc.u64);
+	csr_rd(CVMX_CIU_QLM_JTGC);
+}
+
+/**
+ * Write up to 32bits into the QLM jtag chain. Bits are shifted
+ * into the MSB and out the LSB, so you should shift in the low
+ * order bits followed by the high order bits. The JTAG chain for
+ * CN52XX and CN56XX is 4 * 268 bits long, or 1072. The JTAG chain
+ * for CN63XX is 4 * 300 bits long, or 1200.
+ *
+ * @param qlm    QLM to shift value into
+ * @param bits   Number of bits to shift in (1-32).
+ * @param data   Data to shift in. Bit 0 enters the chain first, followed by
+ *               bit 1, etc.
+ *
+ * @return The low order bits of the JTAG chain that shifted out of the
+ *         circle.
+ */
+uint32_t cvmx_helper_qlm_jtag_shift(int qlm, int bits, uint32_t data)
+{
+	union cvmx_ciu_qlm_jtgc jtgc;
+	union cvmx_ciu_qlm_jtgd jtgd;
+
+	jtgc.u64 = csr_rd(CVMX_CIU_QLM_JTGC);
+	jtgc.s.mux_sel = qlm;
+	csr_wr(CVMX_CIU_QLM_JTGC, jtgc.u64);
+	csr_rd(CVMX_CIU_QLM_JTGC);
+
+	jtgd.u64 = 0;
+	jtgd.s.shift = 1;
+	jtgd.s.shft_cnt = bits - 1;
+	jtgd.s.shft_reg = data;
+	jtgd.s.select = 1 << qlm;
+	csr_wr(CVMX_CIU_QLM_JTGD, jtgd.u64);
+	do {
+		jtgd.u64 = csr_rd(CVMX_CIU_QLM_JTGD);
+	} while (jtgd.s.shift);
+	return jtgd.s.shft_reg >> (32 - bits);
+}
+
+/**
+ * Shift long sequences of zeros into the QLM JTAG chain. It is
+ * common to need to shift more than 32 bits of zeros into the
+ * chain. This function is a convience wrapper around
+ * cvmx_helper_qlm_jtag_shift() to shift more than 32 bits of
+ * zeros at a time.
+ *
+ * @param qlm    QLM to shift zeros into
+ * @param bits
+ */
+void cvmx_helper_qlm_jtag_shift_zeros(int qlm, int bits)
+{
+	while (bits > 0) {
+		int n = bits;
+
+		if (n > 32)
+			n = 32;
+		cvmx_helper_qlm_jtag_shift(qlm, n, 0);
+		bits -= n;
+	}
+}
+
+/**
+ * Program the QLM JTAG chain into all lanes of the QLM. You must
+ * have already shifted in the proper number of bits into the
+ * JTAG chain. Updating invalid values can possibly cause chip damage.
+ *
+ * @param qlm    QLM to program
+ */
+void cvmx_helper_qlm_jtag_update(int qlm)
+{
+	union cvmx_ciu_qlm_jtgc jtgc;
+	union cvmx_ciu_qlm_jtgd jtgd;
+
+	jtgc.u64 = csr_rd(CVMX_CIU_QLM_JTGC);
+	jtgc.s.mux_sel = qlm;
+
+	csr_wr(CVMX_CIU_QLM_JTGC, jtgc.u64);
+	csr_rd(CVMX_CIU_QLM_JTGC);
+
+	/* Update the new data */
+	jtgd.u64 = 0;
+	jtgd.s.update = 1;
+	jtgd.s.select = 1 << qlm;
+	csr_wr(CVMX_CIU_QLM_JTGD, jtgd.u64);
+	do {
+		jtgd.u64 = csr_rd(CVMX_CIU_QLM_JTGD);
+	} while (jtgd.s.update);
+}
+
+/**
+ * Load the QLM JTAG chain with data from all lanes of the QLM.
+ *
+ * @param qlm    QLM to program
+ */
+void cvmx_helper_qlm_jtag_capture(int qlm)
+{
+	union cvmx_ciu_qlm_jtgc jtgc;
+	union cvmx_ciu_qlm_jtgd jtgd;
+
+	jtgc.u64 = csr_rd(CVMX_CIU_QLM_JTGC);
+	jtgc.s.mux_sel = qlm;
+
+	csr_wr(CVMX_CIU_QLM_JTGC, jtgc.u64);
+	csr_rd(CVMX_CIU_QLM_JTGC);
+
+	jtgd.u64 = 0;
+	jtgd.s.capture = 1;
+	jtgd.s.select = 1 << qlm;
+	csr_wr(CVMX_CIU_QLM_JTGD, jtgd.u64);
+	do {
+		jtgd.u64 = csr_rd(CVMX_CIU_QLM_JTGD);
+	} while (jtgd.s.capture);
+}