sc7180: Add SPI QUP driver

This implements the SPI driver for the QUP core.

Change-Id: I86f4fcff6f9537373f70a43711130d7f28bd5e09
Signed-off-by: Roja Rani Yarubandi <rojay@codeaurora.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36517
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 231 insertions, 0 deletions

diff --git a/src/soc/qualcomm/sc7180/qupv3_spi.c b/src/soc/qualcomm/sc7180/qupv3_spi.c
new file mode 100644
index 0000000000..b6999056fb
--- /dev/null
+++ b/src/soc/qualcomm/sc7180/qupv3_spi.c
@@ -0,0 +1,231 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018-2020, The Linux Foundation.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <assert.h>
+#include <delay.h>
+#include <lib.h>
+#include <soc/clock.h>
+#include <soc/gpio.h>
+#include <soc/qcom_qup_se.h>
+#include <soc/qupv3_config.h>
+#include <soc/qupv3_spi.h>
+
+/* SE_SPI_LOOPBACK register fields */
+#define LOOPBACK_ENABLE	0x1
+
+/* SE_SPI_WORD_LEN register fields */
+#define WORD_LEN_MSK	GENMASK(9, 0)
+#define MIN_WORD_LEN	4
+
+/* SPI_TX/SPI_RX_TRANS_LEN fields */
+#define TRANS_LEN_MSK	GENMASK(23, 0)
+
+/* M_CMD OP codes for SPI */
+#define SPI_TX_ONLY	1
+#define SPI_RX_ONLY	2
+#define SPI_FULL_DUPLEX	3
+#define SPI_TX_RX	7
+#define SPI_CS_ASSERT	8
+#define SPI_CS_DEASSERT	9
+#define SPI_SCK_ONLY	10
+
+/* M_CMD params for SPI */
+/* If fragmentation bit is set then CS will not toggle after each transfer */
+#define M_CMD_FRAGMENTATION	BIT(2)
+
+#define BITS_PER_BYTE	8
+#define BITS_PER_WORD	8
+#define TX_WATERMARK	1
+
+#define IRQ_TRIGGER (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN | \
+	M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN | \
+	M_CMD_CANCEL_EN | M_CMD_ABORT_EN)
+
+static void setup_fifo_params(const struct spi_slave *slave)
+{
+	unsigned int se_bus = slave->bus;
+	struct qup_regs *regs = qup[se_bus].regs;
+	u32 word_len = 0;
+
+	/* Disable loopback mode */
+	write32(&regs->proto_loopback_cfg, 0);
+
+	write32(&regs->spi_demux_sel, slave->cs);
+	word_len = ((BITS_PER_WORD - MIN_WORD_LEN) & WORD_LEN_MSK);
+	write32(&regs->spi_word_len, word_len);
+
+	/* FIFO PACKING CONFIGURATION */
+	write32(&regs->geni_tx_packing_cfg0, PACK_VECTOR0
+						| (PACK_VECTOR1 << 10));
+	write32(&regs->geni_tx_packing_cfg1, PACK_VECTOR2
+						| (PACK_VECTOR3 << 10));
+	write32(&regs->geni_rx_packing_cfg0, PACK_VECTOR0
+						| (PACK_VECTOR1 << 10));
+	write32(&regs->geni_rx_packing_cfg1, PACK_VECTOR2
+						| (PACK_VECTOR3 << 10));
+	write32(&regs->geni_byte_granularity, (log2(BITS_PER_WORD) - 3));
+}
+
+static void qup_setup_m_cmd(unsigned int se_bus, u32 cmd, u32 params)
+{
+	struct qup_regs *regs = qup[se_bus].regs;
+	u32 m_cmd = (cmd << M_OPCODE_SHFT);
+
+	m_cmd |= (params & M_PARAMS_MSK);
+	write32(&regs->geni_m_cmd0, m_cmd);
+}
+
+int qup_spi_xfer(const struct spi_slave *slave, const void *dout,
+	size_t bytes_out, void *din, size_t bytes_in)
+{
+	u32 m_cmd = 0;
+	u32 m_param = M_CMD_FRAGMENTATION;
+	int size;
+	unsigned int se_bus = slave->bus;
+	struct qup_regs *regs = qup[se_bus].regs;
+
+	if ((bytes_in == 0) && (bytes_out == 0))
+		return 0;
+
+	setup_fifo_params(slave);
+
+	if (!bytes_out) {
+		size = bytes_in;
+		m_cmd = SPI_RX_ONLY;
+		dout = NULL;
+	} else if (!bytes_in) {
+		size = bytes_out;
+		m_cmd = SPI_TX_ONLY;
+		din = NULL;
+	} else {
+		size = MIN(bytes_in, bytes_out);
+		m_cmd = SPI_FULL_DUPLEX;
+	}
+
+	/* Check for maximum permissible transfer length */
+	assert(!(size & ~TRANS_LEN_MSK));
+
+	if (bytes_out) {
+		write32(&regs->spi_tx_trans_len, size);
+		write32(&regs->geni_tx_watermark_reg, TX_WATERMARK);
+	}
+	if (bytes_in)
+		write32(&regs->spi_rx_trans_len, size);
+
+	qup_setup_m_cmd(se_bus, m_cmd, m_param);
+
+	if (qup_handle_transfer(se_bus, dout, din, size))
+		return -1;
+
+	qup_spi_xfer(slave, dout + size, MAX((int)bytes_out - size, 0),
+			din + size, MAX((int)bytes_in - size, 0));
+
+	return 0;
+}
+
+static int spi_qup_set_cs(const struct spi_slave *slave, bool enable)
+{
+	u32 m_cmd = 0;
+	u32 m_irq = 0;
+	unsigned int se_bus = slave->bus;
+	struct stopwatch sw;
+
+	m_cmd = (enable) ? SPI_CS_ASSERT : SPI_CS_DEASSERT;
+	qup_setup_m_cmd(se_bus, m_cmd, 0);
+
+	stopwatch_init_usecs_expire(&sw, 100);
+	do {
+		m_irq = qup_wait_for_m_irq(se_bus);
+		if (m_irq & M_CMD_DONE_EN) {
+			write32(&qup[se_bus].regs->geni_m_irq_clear, m_irq);
+			break;
+		}
+		write32(&qup[se_bus].regs->geni_m_irq_clear, m_irq);
+	} while (!stopwatch_expired(&sw));
+
+	if (!(m_irq & M_CMD_DONE_EN)) {
+		printk(BIOS_INFO, "%s:Failed to %s chip\n", __func__,
+					(enable) ? "Assert" : "Deassert");
+		qup_m_cancel_and_abort(se_bus);
+		return -1;
+	}
+	return 0;
+}
+
+void qup_spi_init(unsigned int bus, unsigned int speed_hz)
+{
+	u32 m_clk_cfg = 0, div = DEFAULT_SE_CLK / speed_hz;
+	struct qup_regs *regs = qup[bus].regs;
+
+	/* Make sure div can hit target frequency within +/- 1KHz range */
+	assert(((DEFAULT_SE_CLK - speed_hz * div) <= div * KHz) && (div > 0));
+	qupv3_se_fw_load_and_init(bus, SE_PROTOCOL_SPI, MIXED);
+	clock_enable_qup(bus);
+	m_clk_cfg |= ((div << CLK_DIV_SHFT) | SER_CLK_EN);
+	write32(&regs->geni_ser_m_clk_cfg, m_clk_cfg);
+	/* Mode:0, cpha=0, cpol=0 */
+	write32(&regs->spi_cpha, 0);
+	write32(&regs->spi_cpol, 0);
+
+	/* Serial engine IO initialization */
+	write32(&regs->geni_cgc_ctrl, DEFAULT_CGC_EN);
+	write32(&regs->dma_general_cfg,
+		(AHB_SEC_SLV_CLK_CGC_ON | DMA_AHB_SLV_CFG_ON
+		| DMA_TX_CLK_CGC_ON | DMA_RX_CLK_CGC_ON));
+	write32(&regs->geni_output_ctrl,
+			DEFAULT_IO_OUTPUT_CTRL_MSK);
+	write32(&regs->geni_force_default_reg, FORCE_DEFAULT);
+
+	/* Serial engine IO set mode */
+	write32(&regs->se_irq_en, (GENI_M_IRQ_EN |
+			GENI_S_IRQ_EN | DMA_TX_IRQ_EN | DMA_RX_IRQ_EN));
+	write32(&regs->se_gsi_event_en, 0);
+
+	/* Set RX and RFR watermark */
+	write32(&regs->geni_rx_watermark_reg, 0);
+	write32(&regs->geni_rx_rfr_watermark_reg, FIFO_DEPTH - 2);
+
+	/* GPIO Configuration */
+	gpio_configure(qup[bus].pin[0], qup[bus].func[0], GPIO_NO_PULL,
+				GPIO_6MA, GPIO_INPUT);   /* MISO */
+	gpio_configure(qup[bus].pin[1], qup[bus].func[1], GPIO_NO_PULL,
+				GPIO_6MA, GPIO_OUTPUT);  /* MOSI */
+	gpio_configure(qup[bus].pin[2], qup[bus].func[2], GPIO_NO_PULL,
+				GPIO_6MA, GPIO_OUTPUT);  /* CLK */
+	gpio_configure(qup[bus].pin[3], qup[bus].func[3], GPIO_NO_PULL,
+				GPIO_6MA, GPIO_OUTPUT);  /* CS */
+
+	/* Select and setup FIFO mode */
+	write32(&regs->geni_m_irq_clear, 0xFFFFFFFF);
+	write32(&regs->geni_s_irq_clear, 0xFFFFFFFF);
+	write32(&regs->dma_tx_irq_clr, 0xFFFFFFFF);
+	write32(&regs->dma_rx_irq_clr, 0xFFFFFFFF);
+	write32(&regs->geni_m_irq_enable, (M_COMMON_GENI_M_IRQ_EN |
+			M_CMD_DONE_EN |	M_TX_FIFO_WATERMARK_EN |
+			M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN));
+	write32(&regs->geni_s_irq_enable, (S_COMMON_GENI_S_IRQ_EN
+						| S_CMD_DONE_EN));
+	clrbits32(&regs->geni_dma_mode_en, GENI_DMA_MODE_EN);
+}
+
+int qup_spi_claim_bus(const struct spi_slave *slave)
+{
+	return spi_qup_set_cs(slave, 1);
+}
+
+void qup_spi_release_bus(const struct spi_slave *slave)
+{
+	spi_qup_set_cs(slave, 0);
+}