diff mbox series

Applied "spi: spi-geni-qcom: Add SPI driver support for GENI based QUP" to the spi tree

Message ID 20181011145207.6184F11223ED@debutante.sirena.org.uk (mailing list archive)
State Accepted
Commit 561de45f72bd5f9b3f166bdd6151d4d0fe9e6534
Headers show
Series Applied "spi: spi-geni-qcom: Add SPI driver support for GENI based QUP" to the spi tree | expand

Commit Message

Mark Brown Oct. 11, 2018, 2:52 p.m. UTC
The patch

   spi: spi-geni-qcom: Add SPI driver support for GENI based QUP

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 561de45f72bd5f9b3f166bdd6151d4d0fe9e6534 Mon Sep 17 00:00:00 2001
From: Girish Mahadevan <girishm@codeaurora.org>
Date: Wed, 3 Oct 2018 19:14:25 +0530
Subject: [PATCH] spi: spi-geni-qcom: Add SPI driver support for GENI based QUP

This driver supports GENI based SPI Controller in the Qualcomm SOCs. The
Qualcomm Generic Interface (GENI) is a programmable module supporting a
wide range of serial interfaces including SPI. This driver supports SPI
operations using FIFO mode of transfer.

Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
Signed-off-by: Dilip Kota <dkota@codeaurora.org>
Signed-off-by: Alok Chauhan <alokc@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/Kconfig         |  12 +
 drivers/spi/Makefile        |   1 +
 drivers/spi/spi-geni-qcom.c | 703 ++++++++++++++++++++++++++++++++++++
 3 files changed, 716 insertions(+)
 create mode 100644 drivers/spi/spi-geni-qcom.c
diff mbox series

Patch

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 881d499c69b2..7feab4eb9857 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -539,6 +539,18 @@  config SPI_QUP
 	  This driver can also be built as a module.  If so, the module
 	  will be called spi_qup.
 
+config SPI_QCOM_GENI
+	tristate "Qualcomm GENI based SPI controller"
+	depends on QCOM_GENI_SE
+	help
+	  This driver supports GENI serial engine based SPI controller in
+	  master mode on the Qualcomm Technologies Inc.'s SoCs. If you say
+	  yes to this option, support will be included for the built-in SPI
+	  interface on the Qualcomm Technologies Inc.'s SoCs.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called spi-geni-qcom.
+
 config SPI_S3C24XX
 	tristate "Samsung S3C24XX series SPI"
 	depends on ARCH_S3C24XX
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 0eb8b185d8e5..7e7df53fc73a 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -74,6 +74,7 @@  obj-$(CONFIG_SPI_PPC4xx)		+= spi-ppc4xx.o
 spi-pxa2xx-platform-objs		:= spi-pxa2xx.o spi-pxa2xx-dma.o
 obj-$(CONFIG_SPI_PXA2XX)		+= spi-pxa2xx-platform.o
 obj-$(CONFIG_SPI_PXA2XX_PCI)		+= spi-pxa2xx-pci.o
+obj-$(CONFIG_SPI_QCOM_GENI)		+= spi-geni-qcom.o
 obj-$(CONFIG_SPI_QCOM_QSPI)		+= spi-qcom-qspi.o
 obj-$(CONFIG_SPI_QUP)			+= spi-qup.o
 obj-$(CONFIG_SPI_ROCKCHIP)		+= spi-rockchip.o
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
new file mode 100644
index 000000000000..6432ecc4e2ca
--- /dev/null
+++ b/drivers/spi/spi-geni-qcom.c
@@ -0,0 +1,703 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux foundation. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/qcom-geni-se.h>
+#include <linux/spi/spi.h>
+#include <linux/spinlock.h>
+
+/* SPI SE specific registers and respective register fields */
+#define SE_SPI_CPHA		0x224
+#define CPHA			BIT(0)
+
+#define SE_SPI_LOOPBACK		0x22c
+#define LOOPBACK_ENABLE		0x1
+#define NORMAL_MODE		0x0
+#define LOOPBACK_MSK		GENMASK(1, 0)
+
+#define SE_SPI_CPOL		0x230
+#define CPOL			BIT(2)
+
+#define SE_SPI_DEMUX_OUTPUT_INV	0x24c
+#define CS_DEMUX_OUTPUT_INV_MSK	GENMASK(3, 0)
+
+#define SE_SPI_DEMUX_SEL	0x250
+#define CS_DEMUX_OUTPUT_SEL	GENMASK(3, 0)
+
+#define SE_SPI_TRANS_CFG	0x25c
+#define CS_TOGGLE		BIT(0)
+
+#define SE_SPI_WORD_LEN		0x268
+#define WORD_LEN_MSK		GENMASK(9, 0)
+#define MIN_WORD_LEN		4
+
+#define SE_SPI_TX_TRANS_LEN	0x26c
+#define SE_SPI_RX_TRANS_LEN	0x270
+#define TRANS_LEN_MSK		GENMASK(23, 0)
+
+#define SE_SPI_PRE_POST_CMD_DLY	0x274
+
+#define SE_SPI_DELAY_COUNTERS	0x278
+#define SPI_INTER_WORDS_DELAY_MSK	GENMASK(9, 0)
+#define SPI_CS_CLK_DELAY_MSK		GENMASK(19, 10)
+#define SPI_CS_CLK_DELAY_SHFT		10
+
+/* 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 */
+#define SPI_PRE_CMD_DELAY	BIT(0)
+#define TIMESTAMP_BEFORE	BIT(1)
+#define FRAGMENTATION		BIT(2)
+#define TIMESTAMP_AFTER		BIT(3)
+#define POST_CMD_DELAY		BIT(4)
+
+/* SPI M_COMMAND OPCODE */
+enum spi_mcmd_code {
+	CMD_NONE,
+	CMD_XFER,
+	CMD_CS,
+	CMD_CANCEL,
+};
+
+
+struct spi_geni_master {
+	struct geni_se se;
+	struct device *dev;
+	u32 tx_fifo_depth;
+	u32 fifo_width_bits;
+	u32 tx_wm;
+	unsigned long cur_speed_hz;
+	unsigned int cur_bits_per_word;
+	unsigned int tx_rem_bytes;
+	unsigned int rx_rem_bytes;
+	const struct spi_transfer *cur_xfer;
+	struct completion xfer_done;
+	unsigned int oversampling;
+	spinlock_t lock;
+	unsigned int cur_mcmd;
+	int irq;
+};
+
+static void handle_fifo_timeout(struct spi_master *spi,
+				struct spi_message *msg);
+
+static int get_spi_clk_cfg(unsigned int speed_hz,
+			struct spi_geni_master *mas,
+			unsigned int *clk_idx,
+			unsigned int *clk_div)
+{
+	unsigned long sclk_freq;
+	unsigned int actual_hz;
+	struct geni_se *se = &mas->se;
+	int ret;
+
+	ret = geni_se_clk_freq_match(&mas->se,
+				speed_hz * mas->oversampling,
+				clk_idx, &sclk_freq, false);
+	if (ret) {
+		dev_err(mas->dev, "Failed(%d) to find src clk for %dHz\n",
+							ret, speed_hz);
+		return ret;
+	}
+
+	*clk_div = DIV_ROUND_UP(sclk_freq, mas->oversampling * speed_hz);
+	actual_hz = sclk_freq / (mas->oversampling * *clk_div);
+
+	dev_dbg(mas->dev, "req %u=>%u sclk %lu, idx %d, div %d\n", speed_hz,
+				actual_hz, sclk_freq, *clk_idx, *clk_div);
+	ret = clk_set_rate(se->clk, sclk_freq);
+	if (ret)
+		dev_err(mas->dev, "clk_set_rate failed %d\n", ret);
+	return ret;
+}
+
+static void spi_geni_set_cs(struct spi_device *slv, bool set_flag)
+{
+	struct spi_geni_master *mas = spi_master_get_devdata(slv->master);
+	struct spi_master *spi = dev_get_drvdata(mas->dev);
+	struct geni_se *se = &mas->se;
+	unsigned long timeout;
+
+	reinit_completion(&mas->xfer_done);
+	pm_runtime_get_sync(mas->dev);
+	if (!(slv->mode & SPI_CS_HIGH))
+		set_flag = !set_flag;
+
+	mas->cur_mcmd = CMD_CS;
+	if (set_flag)
+		geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
+	else
+		geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
+
+	timeout = wait_for_completion_timeout(&mas->xfer_done, HZ);
+	if (!timeout)
+		handle_fifo_timeout(spi, NULL);
+
+	pm_runtime_put(mas->dev);
+}
+
+static void spi_setup_word_len(struct spi_geni_master *mas, u16 mode,
+					unsigned int bits_per_word)
+{
+	unsigned int pack_words;
+	bool msb_first = (mode & SPI_LSB_FIRST) ? false : true;
+	struct geni_se *se = &mas->se;
+	u32 word_len;
+
+	word_len = readl(se->base + SE_SPI_WORD_LEN);
+
+	/*
+	 * If bits_per_word isn't a byte aligned value, set the packing to be
+	 * 1 SPI word per FIFO word.
+	 */
+	if (!(mas->fifo_width_bits % bits_per_word))
+		pack_words = mas->fifo_width_bits / bits_per_word;
+	else
+		pack_words = 1;
+	word_len &= ~WORD_LEN_MSK;
+	word_len |= ((bits_per_word - MIN_WORD_LEN) & WORD_LEN_MSK);
+	geni_se_config_packing(&mas->se, bits_per_word, pack_words, msb_first,
+								true, true);
+	writel(word_len, se->base + SE_SPI_WORD_LEN);
+}
+
+static int setup_fifo_params(struct spi_device *spi_slv,
+					struct spi_master *spi)
+{
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	struct geni_se *se = &mas->se;
+	u32 loopback_cfg, cpol, cpha, demux_output_inv;
+	u32 demux_sel, clk_sel, m_clk_cfg, idx, div;
+	int ret;
+
+	loopback_cfg = readl(se->base + SE_SPI_LOOPBACK);
+	cpol = readl(se->base + SE_SPI_CPOL);
+	cpha = readl(se->base + SE_SPI_CPHA);
+	demux_output_inv = 0;
+	loopback_cfg &= ~LOOPBACK_MSK;
+	cpol &= ~CPOL;
+	cpha &= ~CPHA;
+
+	if (spi_slv->mode & SPI_LOOP)
+		loopback_cfg |= LOOPBACK_ENABLE;
+
+	if (spi_slv->mode & SPI_CPOL)
+		cpol |= CPOL;
+
+	if (spi_slv->mode & SPI_CPHA)
+		cpha |= CPHA;
+
+	if (spi_slv->mode & SPI_CS_HIGH)
+		demux_output_inv = BIT(spi_slv->chip_select);
+
+	demux_sel = spi_slv->chip_select;
+	mas->cur_speed_hz = spi_slv->max_speed_hz;
+	mas->cur_bits_per_word = spi_slv->bits_per_word;
+
+	ret = get_spi_clk_cfg(mas->cur_speed_hz, mas, &idx, &div);
+	if (ret) {
+		dev_err(mas->dev, "Err setting clks ret(%d) for %ld\n",
+							ret, mas->cur_speed_hz);
+		return ret;
+	}
+
+	clk_sel = idx & CLK_SEL_MSK;
+	m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
+	spi_setup_word_len(mas, spi_slv->mode, spi_slv->bits_per_word);
+	writel(loopback_cfg, se->base + SE_SPI_LOOPBACK);
+	writel(demux_sel, se->base + SE_SPI_DEMUX_SEL);
+	writel(cpha, se->base + SE_SPI_CPHA);
+	writel(cpol, se->base + SE_SPI_CPOL);
+	writel(demux_output_inv, se->base + SE_SPI_DEMUX_OUTPUT_INV);
+	writel(clk_sel, se->base + SE_GENI_CLK_SEL);
+	writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
+	return 0;
+}
+
+static int spi_geni_prepare_message(struct spi_master *spi,
+					struct spi_message *spi_msg)
+{
+	int ret;
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	struct geni_se *se = &mas->se;
+
+	geni_se_select_mode(se, GENI_SE_FIFO);
+	reinit_completion(&mas->xfer_done);
+	ret = setup_fifo_params(spi_msg->spi, spi);
+	if (ret)
+		dev_err(mas->dev, "Couldn't select mode %d\n", ret);
+	return ret;
+}
+
+static int spi_geni_init(struct spi_geni_master *mas)
+{
+	struct geni_se *se = &mas->se;
+	unsigned int proto, major, minor, ver;
+
+	pm_runtime_get_sync(mas->dev);
+
+	proto = geni_se_read_proto(se);
+	if (proto != GENI_SE_SPI) {
+		dev_err(mas->dev, "Invalid proto %d\n", proto);
+		pm_runtime_put(mas->dev);
+		return -ENXIO;
+	}
+	mas->tx_fifo_depth = geni_se_get_tx_fifo_depth(se);
+
+	/* Width of Tx and Rx FIFO is same */
+	mas->fifo_width_bits = geni_se_get_tx_fifo_width(se);
+
+	/*
+	 * Hardware programming guide suggests to configure
+	 * RX FIFO RFR level to fifo_depth-2.
+	 */
+	geni_se_init(se, 0x0, mas->tx_fifo_depth - 2);
+	/* Transmit an entire FIFO worth of data per IRQ */
+	mas->tx_wm = 1;
+	ver = geni_se_get_qup_hw_version(se);
+	major = GENI_SE_VERSION_MAJOR(ver);
+	minor = GENI_SE_VERSION_MINOR(ver);
+
+	if (major == 1 && minor == 0)
+		mas->oversampling = 2;
+	else
+		mas->oversampling = 1;
+
+	pm_runtime_put(mas->dev);
+	return 0;
+}
+
+static void setup_fifo_xfer(struct spi_transfer *xfer,
+				struct spi_geni_master *mas,
+				u16 mode, struct spi_master *spi)
+{
+	u32 m_cmd = 0;
+	u32 spi_tx_cfg, len;
+	struct geni_se *se = &mas->se;
+
+	spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
+	if (xfer->bits_per_word != mas->cur_bits_per_word) {
+		spi_setup_word_len(mas, mode, xfer->bits_per_word);
+		mas->cur_bits_per_word = xfer->bits_per_word;
+	}
+
+	/* Speed and bits per word can be overridden per transfer */
+	if (xfer->speed_hz != mas->cur_speed_hz) {
+		int ret;
+		u32 clk_sel, m_clk_cfg;
+		unsigned int idx, div;
+
+		ret = get_spi_clk_cfg(xfer->speed_hz, mas, &idx, &div);
+		if (ret) {
+			dev_err(mas->dev, "Err setting clks:%d\n", ret);
+			return;
+		}
+		/*
+		 * SPI core clock gets configured with the requested frequency
+		 * or the frequency closer to the requested frequency.
+		 * For that reason requested frequency is stored in the
+		 * cur_speed_hz and referred in the consecutive transfer instead
+		 * of calling clk_get_rate() API.
+		 */
+		mas->cur_speed_hz = xfer->speed_hz;
+		clk_sel = idx & CLK_SEL_MSK;
+		m_clk_cfg = (div << CLK_DIV_SHFT) | SER_CLK_EN;
+		writel(clk_sel, se->base + SE_GENI_CLK_SEL);
+		writel(m_clk_cfg, se->base + GENI_SER_M_CLK_CFG);
+	}
+
+	mas->tx_rem_bytes = 0;
+	mas->rx_rem_bytes = 0;
+	if (xfer->tx_buf && xfer->rx_buf)
+		m_cmd = SPI_FULL_DUPLEX;
+	else if (xfer->tx_buf)
+		m_cmd = SPI_TX_ONLY;
+	else if (xfer->rx_buf)
+		m_cmd = SPI_RX_ONLY;
+
+	spi_tx_cfg &= ~CS_TOGGLE;
+
+	if (!(mas->cur_bits_per_word % MIN_WORD_LEN))
+		len = xfer->len * BITS_PER_BYTE / mas->cur_bits_per_word;
+	else
+		len = xfer->len / (mas->cur_bits_per_word / BITS_PER_BYTE + 1);
+	len &= TRANS_LEN_MSK;
+
+	mas->cur_xfer = xfer;
+	if (m_cmd & SPI_TX_ONLY) {
+		mas->tx_rem_bytes = xfer->len;
+		writel(len, se->base + SE_SPI_TX_TRANS_LEN);
+	}
+
+	if (m_cmd & SPI_RX_ONLY) {
+		writel(len, se->base + SE_SPI_RX_TRANS_LEN);
+		mas->rx_rem_bytes = xfer->len;
+	}
+	writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
+	mas->cur_mcmd = CMD_XFER;
+	geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
+
+	/*
+	 * TX_WATERMARK_REG should be set after SPI configuration and
+	 * setting up GENI SE engine, as driver starts data transfer
+	 * for the watermark interrupt.
+	 */
+	if (m_cmd & SPI_TX_ONLY)
+		writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
+}
+
+static void handle_fifo_timeout(struct spi_master *spi,
+				struct spi_message *msg)
+{
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	unsigned long time_left, flags;
+	struct geni_se *se = &mas->se;
+
+	spin_lock_irqsave(&mas->lock, flags);
+	reinit_completion(&mas->xfer_done);
+	mas->cur_mcmd = CMD_CANCEL;
+	geni_se_cancel_m_cmd(se);
+	writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+	spin_unlock_irqrestore(&mas->lock, flags);
+	time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+	if (time_left)
+		return;
+
+	spin_lock_irqsave(&mas->lock, flags);
+	reinit_completion(&mas->xfer_done);
+	geni_se_abort_m_cmd(se);
+	spin_unlock_irqrestore(&mas->lock, flags);
+	time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+	if (!time_left)
+		dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
+}
+
+static int spi_geni_transfer_one(struct spi_master *spi,
+				struct spi_device *slv,
+				struct spi_transfer *xfer)
+{
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+
+	/* Terminate and return success for 0 byte length transfer */
+	if (!xfer->len)
+		return 0;
+
+	setup_fifo_xfer(xfer, mas, slv->mode, spi);
+	return 1;
+}
+
+static unsigned int geni_byte_per_fifo_word(struct spi_geni_master *mas)
+{
+	/*
+	 * Calculate how many bytes we'll put in each FIFO word.  If the
+	 * transfer words don't pack cleanly into a FIFO word we'll just put
+	 * one transfer word in each FIFO word.  If they do pack we'll pack 'em.
+	 */
+	if (mas->fifo_width_bits % mas->cur_bits_per_word)
+		return roundup_pow_of_two(DIV_ROUND_UP(mas->cur_bits_per_word,
+						       BITS_PER_BYTE));
+
+	return mas->fifo_width_bits / BITS_PER_BYTE;
+}
+
+static void geni_spi_handle_tx(struct spi_geni_master *mas)
+{
+	struct geni_se *se = &mas->se;
+	unsigned int max_bytes;
+	const u8 *tx_buf;
+	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
+	unsigned int i = 0;
+
+	max_bytes = (mas->tx_fifo_depth - mas->tx_wm) * bytes_per_fifo_word;
+	if (mas->tx_rem_bytes < max_bytes)
+		max_bytes = mas->tx_rem_bytes;
+
+	tx_buf = mas->cur_xfer->tx_buf + mas->cur_xfer->len - mas->tx_rem_bytes;
+	while (i < max_bytes) {
+		unsigned int j;
+		unsigned int bytes_to_write;
+		u32 fifo_word = 0;
+		u8 *fifo_byte = (u8 *)&fifo_word;
+
+		bytes_to_write = min(bytes_per_fifo_word, max_bytes - i);
+		for (j = 0; j < bytes_to_write; j++)
+			fifo_byte[j] = tx_buf[i++];
+		iowrite32_rep(se->base + SE_GENI_TX_FIFOn, &fifo_word, 1);
+	}
+	mas->tx_rem_bytes -= max_bytes;
+	if (!mas->tx_rem_bytes)
+		writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+}
+
+static void geni_spi_handle_rx(struct spi_geni_master *mas)
+{
+	struct geni_se *se = &mas->se;
+	u32 rx_fifo_status;
+	unsigned int rx_bytes;
+	unsigned int rx_last_byte_valid;
+	u8 *rx_buf;
+	unsigned int bytes_per_fifo_word = geni_byte_per_fifo_word(mas);
+	unsigned int i = 0;
+
+	rx_fifo_status = readl(se->base + SE_GENI_RX_FIFO_STATUS);
+	rx_bytes = (rx_fifo_status & RX_FIFO_WC_MSK) * bytes_per_fifo_word;
+	if (rx_fifo_status & RX_LAST) {
+		rx_last_byte_valid = rx_fifo_status & RX_LAST_BYTE_VALID_MSK;
+		rx_last_byte_valid >>= RX_LAST_BYTE_VALID_SHFT;
+		if (rx_last_byte_valid && rx_last_byte_valid < 4)
+			rx_bytes -= bytes_per_fifo_word - rx_last_byte_valid;
+	}
+	if (mas->rx_rem_bytes < rx_bytes)
+		rx_bytes = mas->rx_rem_bytes;
+
+	rx_buf = mas->cur_xfer->rx_buf + mas->cur_xfer->len - mas->rx_rem_bytes;
+	while (i < rx_bytes) {
+		u32 fifo_word = 0;
+		u8 *fifo_byte = (u8 *)&fifo_word;
+		unsigned int bytes_to_read;
+		unsigned int j;
+
+		bytes_to_read = min(bytes_per_fifo_word, rx_bytes - i);
+		ioread32_rep(se->base + SE_GENI_RX_FIFOn, &fifo_word, 1);
+		for (j = 0; j < bytes_to_read; j++)
+			rx_buf[i++] = fifo_byte[j];
+	}
+	mas->rx_rem_bytes -= rx_bytes;
+}
+
+static irqreturn_t geni_spi_isr(int irq, void *data)
+{
+	struct spi_master *spi = data;
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+	struct geni_se *se = &mas->se;
+	u32 m_irq;
+	unsigned long flags;
+	irqreturn_t ret = IRQ_HANDLED;
+
+	if (mas->cur_mcmd == CMD_NONE)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&mas->lock, flags);
+	m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
+
+	if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
+		geni_spi_handle_rx(mas);
+
+	if (m_irq & M_TX_FIFO_WATERMARK_EN)
+		geni_spi_handle_tx(mas);
+
+	if (m_irq & M_CMD_DONE_EN) {
+		if (mas->cur_mcmd == CMD_XFER)
+			spi_finalize_current_transfer(spi);
+		else if (mas->cur_mcmd == CMD_CS)
+			complete(&mas->xfer_done);
+		mas->cur_mcmd = CMD_NONE;
+		/*
+		 * If this happens, then a CMD_DONE came before all the Tx
+		 * buffer bytes were sent out. This is unusual, log this
+		 * condition and disable the WM interrupt to prevent the
+		 * system from stalling due an interrupt storm.
+		 * If this happens when all Rx bytes haven't been received, log
+		 * the condition.
+		 * The only known time this can happen is if bits_per_word != 8
+		 * and some registers that expect xfer lengths in num spi_words
+		 * weren't written correctly.
+		 */
+		if (mas->tx_rem_bytes) {
+			writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+			dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
+				mas->tx_rem_bytes, mas->cur_bits_per_word);
+		}
+		if (mas->rx_rem_bytes)
+			dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
+				mas->rx_rem_bytes, mas->cur_bits_per_word);
+	}
+
+	if ((m_irq & M_CMD_CANCEL_EN) || (m_irq & M_CMD_ABORT_EN)) {
+		mas->cur_mcmd = CMD_NONE;
+		complete(&mas->xfer_done);
+	}
+
+	writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
+	spin_unlock_irqrestore(&mas->lock, flags);
+	return ret;
+}
+
+static int spi_geni_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct spi_master *spi;
+	struct spi_geni_master *mas;
+	struct resource *res;
+	struct geni_se *se;
+
+	spi = spi_alloc_master(&pdev->dev, sizeof(*mas));
+	if (!spi)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, spi);
+	mas = spi_master_get_devdata(spi);
+	mas->dev = &pdev->dev;
+	mas->se.dev = &pdev->dev;
+	mas->se.wrapper = dev_get_drvdata(pdev->dev.parent);
+	se = &mas->se;
+
+	spi->bus_num = -1;
+	spi->dev.of_node = pdev->dev.of_node;
+	mas->se.clk = devm_clk_get(&pdev->dev, "se");
+	if (IS_ERR(mas->se.clk)) {
+		ret = PTR_ERR(mas->se.clk);
+		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
+		goto spi_geni_probe_err;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	se->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(se->base)) {
+		ret = PTR_ERR(se->base);
+		goto spi_geni_probe_err;
+	}
+
+	spi->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP | SPI_CS_HIGH;
+	spi->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
+	spi->num_chipselect = 4;
+	spi->max_speed_hz = 50000000;
+	spi->prepare_message = spi_geni_prepare_message;
+	spi->transfer_one = spi_geni_transfer_one;
+	spi->auto_runtime_pm = true;
+	spi->handle_err = handle_fifo_timeout;
+	spi->set_cs = spi_geni_set_cs;
+
+	init_completion(&mas->xfer_done);
+	spin_lock_init(&mas->lock);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = spi_geni_init(mas);
+	if (ret)
+		goto spi_geni_probe_runtime_disable;
+
+	mas->irq = platform_get_irq(pdev, 0);
+	if (mas->irq < 0) {
+		ret = mas->irq;
+		dev_err(&pdev->dev, "Err getting IRQ %d\n", ret);
+		goto spi_geni_probe_runtime_disable;
+	}
+
+	ret = request_irq(mas->irq, geni_spi_isr,
+			IRQF_TRIGGER_HIGH, "spi_geni", spi);
+	if (ret)
+		goto spi_geni_probe_runtime_disable;
+
+	ret = spi_register_master(spi);
+	if (ret)
+		goto spi_geni_probe_free_irq;
+
+	return 0;
+spi_geni_probe_free_irq:
+	free_irq(mas->irq, spi);
+spi_geni_probe_runtime_disable:
+	pm_runtime_disable(&pdev->dev);
+spi_geni_probe_err:
+	spi_master_put(spi);
+	return ret;
+}
+
+static int spi_geni_remove(struct platform_device *pdev)
+{
+	struct spi_master *spi = platform_get_drvdata(pdev);
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+
+	/* Unregister _before_ disabling pm_runtime() so we stop transfers */
+	spi_unregister_master(spi);
+
+	free_irq(mas->irq, spi);
+	pm_runtime_disable(&pdev->dev);
+	return 0;
+}
+
+static int __maybe_unused spi_geni_runtime_suspend(struct device *dev)
+{
+	struct spi_master *spi = dev_get_drvdata(dev);
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+
+	return geni_se_resources_off(&mas->se);
+}
+
+static int __maybe_unused spi_geni_runtime_resume(struct device *dev)
+{
+	struct spi_master *spi = dev_get_drvdata(dev);
+	struct spi_geni_master *mas = spi_master_get_devdata(spi);
+
+	return geni_se_resources_on(&mas->se);
+}
+
+static int __maybe_unused spi_geni_suspend(struct device *dev)
+{
+	struct spi_master *spi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = spi_master_suspend(spi);
+	if (ret)
+		return ret;
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret)
+		spi_master_resume(spi);
+
+	return ret;
+}
+
+static int __maybe_unused spi_geni_resume(struct device *dev)
+{
+	struct spi_master *spi = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_force_resume(dev);
+	if (ret)
+		return ret;
+
+	ret = spi_master_resume(spi);
+	if (ret)
+		pm_runtime_force_suspend(dev);
+
+	return ret;
+}
+
+static const struct dev_pm_ops spi_geni_pm_ops = {
+	SET_RUNTIME_PM_OPS(spi_geni_runtime_suspend,
+					spi_geni_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(spi_geni_suspend, spi_geni_resume)
+};
+
+static const struct of_device_id spi_geni_dt_match[] = {
+	{ .compatible = "qcom,geni-spi" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, spi_geni_dt_match);
+
+static struct platform_driver spi_geni_driver = {
+	.probe  = spi_geni_probe,
+	.remove = spi_geni_remove,
+	.driver = {
+		.name = "geni_spi",
+		.pm = &spi_geni_pm_ops,
+		.of_match_table = spi_geni_dt_match,
+	},
+};
+module_platform_driver(spi_geni_driver);
+
+MODULE_DESCRIPTION("SPI driver for GENI based QUP cores");
+MODULE_LICENSE("GPL v2");