soc: qcom: Add GENI based QUP Wrapper driver

This driver manages the Generic Interface (GENI) firmware based Qualcomm
Universal Peripheral (QUP) Wrapper. GENI based QUP is the next generation
programmable module composed of multiple Serial Engines (SE) and supports
a wide range of serial interfaces like UART, SPI, I2C, I3C, etc. This
driver also enables managing the serial interface independent aspects of
Serial Engines.

Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>
Signed-off-by: Girish Mahadevan <girishm@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

3 files changed, 758 insertions, 0 deletions

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 5c4535b545cc..d0372de29834 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -3,6 +3,15 @@
 #
 menu "Qualcomm SoC drivers"
 
+config QCOM_GENI_SE
+	tristate "QCOM GENI Serial Engine Driver"
+	depends on ARCH_QCOM || COMPILE_TEST
+	help
+	  This driver is used to manage Generic Interface (GENI) firmware based
+	  Qualcomm Technologies, Inc. Universal Peripheral (QUP) Wrapper. This
+	  driver is also used to manage the common aspects of multiple Serial
+	  Engines present in the QUP.
+
 config QCOM_GLINK_SSR
 	tristate "Qualcomm Glink SSR driver"
 	depends on RPMSG
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index dcebf2814e6d..959aa748f5ac 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_QCOM_GENI_SE) +=	qcom-geni-se.o
 obj-$(CONFIG_QCOM_GLINK_SSR) +=	glink_ssr.o
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
 obj-$(CONFIG_QCOM_MDT_LOADER)	+= mdt_loader.o
diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
new file mode 100644
index 000000000000..feed3db21c10
--- /dev/null
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -0,0 +1,748 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/platform_device.h>
+#include <linux/qcom-geni-se.h>
+
+/**
+ * DOC: Overview
+ *
+ * Generic Interface (GENI) Serial Engine (SE) Wrapper driver is introduced
+ * to manage GENI firmware based Qualcomm Universal Peripheral (QUP) Wrapper
+ * controller. QUP Wrapper is designed to support various serial bus protocols
+ * like UART, SPI, I2C, I3C, etc.
+ */
+
+/**
+ * DOC: Hardware description
+ *
+ * GENI based QUP is a highly-flexible and programmable module for supporting
+ * a wide range of serial interfaces like UART, SPI, I2C, I3C, etc. A single
+ * QUP module can provide upto 8 serial interfaces, using its internal
+ * serial engines. The actual configuration is determined by the target
+ * platform configuration. The protocol supported by each interface is
+ * determined by the firmware loaded to the serial engine. Each SE consists
+ * of a DMA Engine and GENI sub modules which enable serial engines to
+ * support FIFO and DMA modes of operation.
+ *
+ *
+ *                      +-----------------------------------------+
+ *                      |QUP Wrapper                              |
+ *                      |         +----------------------------+  |
+ *   --QUP & SE Clocks-->         | Serial Engine N            |  +-IO------>
+ *                      |         | ...                        |  | Interface
+ *   <---Clock Perf.----+    +----+-----------------------+    |  |
+ *     State Interface  |    | Serial Engine 1            |    |  |
+ *                      |    |                            |    |  |
+ *                      |    |                            |    |  |
+ *   <--------AHB------->    |                            |    |  |
+ *                      |    |                            +----+  |
+ *                      |    |                            |       |
+ *                      |    |                            |       |
+ *   <------SE IRQ------+    +----------------------------+       |
+ *                      |                                         |
+ *                      +-----------------------------------------+
+ *
+ *                         Figure 1: GENI based QUP Wrapper
+ *
+ * The GENI submodules include primary and secondary sequencers which are
+ * used to drive TX & RX operations. On serial interfaces that operate using
+ * master-slave model, primary sequencer drives both TX & RX operations. On
+ * serial interfaces that operate using peer-to-peer model, primary sequencer
+ * drives TX operation and secondary sequencer drives RX operation.
+ */
+
+/**
+ * DOC: Software description
+ *
+ * GENI SE Wrapper driver is structured into 2 parts:
+ *
+ * geni_wrapper represents QUP Wrapper controller. This part of the driver
+ * manages QUP Wrapper information such as hardware version, clock
+ * performance table that is common to all the internal serial engines.
+ *
+ * geni_se represents serial engine. This part of the driver manages serial
+ * engine information such as clocks, containing QUP Wrapper, etc. This part
+ * of driver also supports operations (eg. initialize the concerned serial
+ * engine, select between FIFO and DMA mode of operation etc.) that are
+ * common to all the serial engines and are independent of serial interfaces.
+ */
+
+#define MAX_CLK_PERF_LEVEL 32
+#define NUM_AHB_CLKS 2
+
+/**
+ * @struct geni_wrapper - Data structure to represent the QUP Wrapper Core
+ * @dev:		Device pointer of the QUP wrapper core
+ * @base:		Base address of this instance of QUP wrapper core
+ * @ahb_clks:		Handle to the primary & secondary AHB clocks
+ */
+struct geni_wrapper {
+	struct device *dev;
+	void __iomem *base;
+	struct clk_bulk_data ahb_clks[NUM_AHB_CLKS];
+};
+
+#define QUP_HW_VER_REG			0x4
+
+/* Common SE registers */
+#define GENI_INIT_CFG_REVISION		0x0
+#define GENI_S_INIT_CFG_REVISION	0x4
+#define GENI_OUTPUT_CTRL		0x24
+#define GENI_CGC_CTRL			0x28
+#define GENI_CLK_CTRL_RO		0x60
+#define GENI_IF_DISABLE_RO		0x64
+#define GENI_FW_S_REVISION_RO		0x6c
+#define SE_GENI_BYTE_GRAN		0x254
+#define SE_GENI_TX_PACKING_CFG0		0x260
+#define SE_GENI_TX_PACKING_CFG1		0x264
+#define SE_GENI_RX_PACKING_CFG0		0x284
+#define SE_GENI_RX_PACKING_CFG1		0x288
+#define SE_GENI_M_GP_LENGTH		0x910
+#define SE_GENI_S_GP_LENGTH		0x914
+#define SE_DMA_TX_PTR_L			0xc30
+#define SE_DMA_TX_PTR_H			0xc34
+#define SE_DMA_TX_ATTR			0xc38
+#define SE_DMA_TX_LEN			0xc3c
+#define SE_DMA_TX_IRQ_EN		0xc48
+#define SE_DMA_TX_IRQ_EN_SET		0xc4c
+#define SE_DMA_TX_IRQ_EN_CLR		0xc50
+#define SE_DMA_TX_LEN_IN		0xc54
+#define SE_DMA_TX_MAX_BURST		0xc5c
+#define SE_DMA_RX_PTR_L			0xd30
+#define SE_DMA_RX_PTR_H			0xd34
+#define SE_DMA_RX_ATTR			0xd38
+#define SE_DMA_RX_LEN			0xd3c
+#define SE_DMA_RX_IRQ_EN		0xd48
+#define SE_DMA_RX_IRQ_EN_SET		0xd4c
+#define SE_DMA_RX_IRQ_EN_CLR		0xd50
+#define SE_DMA_RX_LEN_IN		0xd54
+#define SE_DMA_RX_MAX_BURST		0xd5c
+#define SE_DMA_RX_FLUSH			0xd60
+#define SE_GSI_EVENT_EN			0xe18
+#define SE_IRQ_EN			0xe1c
+#define SE_DMA_GENERAL_CFG		0xe30
+
+/* GENI_OUTPUT_CTRL fields */
+#define DEFAULT_IO_OUTPUT_CTRL_MSK	GENMASK(6, 0)
+
+/* GENI_CGC_CTRL fields */
+#define CFG_AHB_CLK_CGC_ON		BIT(0)
+#define CFG_AHB_WR_ACLK_CGC_ON		BIT(1)
+#define DATA_AHB_CLK_CGC_ON		BIT(2)
+#define SCLK_CGC_ON			BIT(3)
+#define TX_CLK_CGC_ON			BIT(4)
+#define RX_CLK_CGC_ON			BIT(5)
+#define EXT_CLK_CGC_ON			BIT(6)
+#define PROG_RAM_HCLK_OFF		BIT(8)
+#define PROG_RAM_SCLK_OFF		BIT(9)
+#define DEFAULT_CGC_EN			GENMASK(6, 0)
+
+/* SE_GSI_EVENT_EN fields */
+#define DMA_RX_EVENT_EN			BIT(0)
+#define DMA_TX_EVENT_EN			BIT(1)
+#define GENI_M_EVENT_EN			BIT(2)
+#define GENI_S_EVENT_EN			BIT(3)
+
+/* SE_IRQ_EN fields */
+#define DMA_RX_IRQ_EN			BIT(0)
+#define DMA_TX_IRQ_EN			BIT(1)
+#define GENI_M_IRQ_EN			BIT(2)
+#define GENI_S_IRQ_EN			BIT(3)
+
+/* SE_DMA_GENERAL_CFG */
+#define DMA_RX_CLK_CGC_ON		BIT(0)
+#define DMA_TX_CLK_CGC_ON		BIT(1)
+#define DMA_AHB_SLV_CFG_ON		BIT(2)
+#define AHB_SEC_SLV_CLK_CGC_ON		BIT(3)
+#define DUMMY_RX_NON_BUFFERABLE		BIT(4)
+#define RX_DMA_ZERO_PADDING_EN		BIT(5)
+#define RX_DMA_IRQ_DELAY_MSK		GENMASK(8, 6)
+#define RX_DMA_IRQ_DELAY_SHFT		6
+
+/**
+ * geni_se_get_qup_hw_version() - Read the QUP wrapper Hardware version
+ * @se:	Pointer to the corresponding serial engine.
+ *
+ * Return: Hardware Version of the wrapper.
+ */
+u32 geni_se_get_qup_hw_version(struct geni_se *se)
+{
+	struct geni_wrapper *wrapper = se->wrapper;
+
+	return readl_relaxed(wrapper->base + QUP_HW_VER_REG);
+}
+EXPORT_SYMBOL(geni_se_get_qup_hw_version);
+
+static void geni_se_io_set_mode(void __iomem *base)
+{
+	u32 val;
+
+	val = readl_relaxed(base + SE_IRQ_EN);
+	val |= GENI_M_IRQ_EN | GENI_S_IRQ_EN;
+	val |= DMA_TX_IRQ_EN | DMA_RX_IRQ_EN;
+	writel_relaxed(val, base + SE_IRQ_EN);
+
+	val = readl_relaxed(base + SE_GENI_DMA_MODE_EN);
+	val &= ~GENI_DMA_MODE_EN;
+	writel_relaxed(val, base + SE_GENI_DMA_MODE_EN);
+
+	writel_relaxed(0, base + SE_GSI_EVENT_EN);
+}
+
+static void geni_se_io_init(void __iomem *base)
+{
+	u32 val;
+
+	val = readl_relaxed(base + GENI_CGC_CTRL);
+	val |= DEFAULT_CGC_EN;
+	writel_relaxed(val, base + GENI_CGC_CTRL);
+
+	val = readl_relaxed(base + SE_DMA_GENERAL_CFG);
+	val |= AHB_SEC_SLV_CLK_CGC_ON | DMA_AHB_SLV_CFG_ON;
+	val |= DMA_TX_CLK_CGC_ON | DMA_RX_CLK_CGC_ON;
+	writel_relaxed(val, base + SE_DMA_GENERAL_CFG);
+
+	writel_relaxed(DEFAULT_IO_OUTPUT_CTRL_MSK, base + GENI_OUTPUT_CTRL);
+	writel_relaxed(FORCE_DEFAULT, base + GENI_FORCE_DEFAULT_REG);
+}
+
+/**
+ * geni_se_init() - Initialize the GENI serial engine
+ * @se:		Pointer to the concerned serial engine.
+ * @rx_wm:	Receive watermark, in units of FIFO words.
+ * @rx_rfr_wm:	Ready-for-receive watermark, in units of FIFO words.
+ *
+ * This function is used to initialize the GENI serial engine, configure
+ * receive watermark and ready-for-receive watermarks.
+ */
+void geni_se_init(struct geni_se *se, u32 rx_wm, u32 rx_rfr)
+{
+	u32 val;
+
+	geni_se_io_init(se->base);
+	geni_se_io_set_mode(se->base);
+
+	writel_relaxed(rx_wm, se->base + SE_GENI_RX_WATERMARK_REG);
+	writel_relaxed(rx_rfr, se->base + SE_GENI_RX_RFR_WATERMARK_REG);
+
+	val = readl_relaxed(se->base + SE_GENI_M_IRQ_EN);
+	val |= M_COMMON_GENI_M_IRQ_EN;
+	writel_relaxed(val, se->base + SE_GENI_M_IRQ_EN);
+
+	val = readl_relaxed(se->base + SE_GENI_S_IRQ_EN);
+	val |= S_COMMON_GENI_S_IRQ_EN;
+	writel_relaxed(val, se->base + SE_GENI_S_IRQ_EN);
+}
+EXPORT_SYMBOL(geni_se_init);
+
+static void geni_se_select_fifo_mode(struct geni_se *se)
+{
+	u32 proto = geni_se_read_proto(se);
+	u32 val;
+
+	writel_relaxed(0, se->base + SE_GSI_EVENT_EN);
+	writel_relaxed(0xffffffff, se->base + SE_GENI_M_IRQ_CLEAR);
+	writel_relaxed(0xffffffff, se->base + SE_GENI_S_IRQ_CLEAR);
+	writel_relaxed(0xffffffff, se->base + SE_DMA_TX_IRQ_CLR);
+	writel_relaxed(0xffffffff, se->base + SE_DMA_RX_IRQ_CLR);
+	writel_relaxed(0xffffffff, se->base + SE_IRQ_EN);
+
+	val = readl_relaxed(se->base + SE_GENI_M_IRQ_EN);
+	if (proto != GENI_SE_UART) {
+		val |= M_CMD_DONE_EN | M_TX_FIFO_WATERMARK_EN;
+		val |= M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN;
+	}
+	writel_relaxed(val, se->base + SE_GENI_M_IRQ_EN);
+
+	val = readl_relaxed(se->base + SE_GENI_S_IRQ_EN);
+	if (proto != GENI_SE_UART)
+		val |= S_CMD_DONE_EN;
+	writel_relaxed(val, se->base + SE_GENI_S_IRQ_EN);
+
+	val = readl_relaxed(se->base + SE_GENI_DMA_MODE_EN);
+	val &= ~GENI_DMA_MODE_EN;
+	writel_relaxed(val, se->base + SE_GENI_DMA_MODE_EN);
+}
+
+static void geni_se_select_dma_mode(struct geni_se *se)
+{
+	u32 val;
+
+	writel_relaxed(0, se->base + SE_GSI_EVENT_EN);
+	writel_relaxed(0xffffffff, se->base + SE_GENI_M_IRQ_CLEAR);
+	writel_relaxed(0xffffffff, se->base + SE_GENI_S_IRQ_CLEAR);
+	writel_relaxed(0xffffffff, se->base + SE_DMA_TX_IRQ_CLR);
+	writel_relaxed(0xffffffff, se->base + SE_DMA_RX_IRQ_CLR);
+	writel_relaxed(0xffffffff, se->base + SE_IRQ_EN);
+
+	val = readl_relaxed(se->base + SE_GENI_DMA_MODE_EN);
+	val |= GENI_DMA_MODE_EN;
+	writel_relaxed(val, se->base + SE_GENI_DMA_MODE_EN);
+}
+
+/**
+ * geni_se_select_mode() - Select the serial engine transfer mode
+ * @se:		Pointer to the concerned serial engine.
+ * @mode:	Transfer mode to be selected.
+ */
+void geni_se_select_mode(struct geni_se *se, enum geni_se_xfer_mode mode)
+{
+	WARN_ON(mode != GENI_SE_FIFO && mode != GENI_SE_DMA);
+
+	switch (mode) {
+	case GENI_SE_FIFO:
+		geni_se_select_fifo_mode(se);
+		break;
+	case GENI_SE_DMA:
+		geni_se_select_dma_mode(se);
+		break;
+	case GENI_SE_INVALID:
+	default:
+		break;
+	}
+}
+EXPORT_SYMBOL(geni_se_select_mode);
+
+/**
+ * DOC: Overview
+ *
+ * GENI FIFO packing is highly configurable. TX/RX packing/unpacking consist
+ * of up to 4 operations, each operation represented by 4 configuration vectors
+ * of 10 bits programmed in GENI_TX_PACKING_CFG0 and GENI_TX_PACKING_CFG1 for
+ * TX FIFO and in GENI_RX_PACKING_CFG0 and GENI_RX_PACKING_CFG1 for RX FIFO.
+ * Refer to below examples for detailed bit-field description.
+ *
+ * Example 1: word_size = 7, packing_mode = 4 x 8, msb_to_lsb = 1
+ *
+ *        +-----------+-------+-------+-------+-------+
+ *        |           | vec_0 | vec_1 | vec_2 | vec_3 |
+ *        +-----------+-------+-------+-------+-------+
+ *        | start     | 0x6   | 0xe   | 0x16  | 0x1e  |
+ *        | direction | 1     | 1     | 1     | 1     |
+ *        | length    | 6     | 6     | 6     | 6     |
+ *        | stop      | 0     | 0     | 0     | 1     |
+ *        +-----------+-------+-------+-------+-------+
+ *
+ * Example 2: word_size = 15, packing_mode = 2 x 16, msb_to_lsb = 0
+ *
+ *        +-----------+-------+-------+-------+-------+
+ *        |           | vec_0 | vec_1 | vec_2 | vec_3 |
+ *        +-----------+-------+-------+-------+-------+
+ *        | start     | 0x0   | 0x8   | 0x10  | 0x18  |
+ *        | direction | 0     | 0     | 0     | 0     |
+ *        | length    | 7     | 6     | 7     | 6     |
+ *        | stop      | 0     | 0     | 0     | 1     |
+ *        +-----------+-------+-------+-------+-------+
+ *
+ * Example 3: word_size = 23, packing_mode = 1 x 32, msb_to_lsb = 1
+ *
+ *        +-----------+-------+-------+-------+-------+
+ *        |           | vec_0 | vec_1 | vec_2 | vec_3 |
+ *        +-----------+-------+-------+-------+-------+
+ *        | start     | 0x16  | 0xe   | 0x6   | 0x0   |
+ *        | direction | 1     | 1     | 1     | 1     |
+ *        | length    | 7     | 7     | 6     | 0     |
+ *        | stop      | 0     | 0     | 1     | 0     |
+ *        +-----------+-------+-------+-------+-------+
+ *
+ */
+
+#define NUM_PACKING_VECTORS 4
+#define PACKING_START_SHIFT 5
+#define PACKING_DIR_SHIFT 4
+#define PACKING_LEN_SHIFT 1
+#define PACKING_STOP_BIT BIT(0)
+#define PACKING_VECTOR_SHIFT 10
+/**
+ * geni_se_config_packing() - Packing configuration of the serial engine
+ * @se:		Pointer to the concerned serial engine
+ * @bpw:	Bits of data per transfer word.
+ * @pack_words:	Number of words per fifo element.
+ * @msb_to_lsb:	Transfer from MSB to LSB or vice-versa.
+ * @tx_cfg:	Flag to configure the TX Packing.
+ * @rx_cfg:	Flag to configure the RX Packing.
+ *
+ * This function is used to configure the packing rules for the current
+ * transfer.
+ */
+void geni_se_config_packing(struct geni_se *se, int bpw, int pack_words,
+			    bool msb_to_lsb, bool tx_cfg, bool rx_cfg)
+{
+	u32 cfg0, cfg1, cfg[NUM_PACKING_VECTORS] = {0};
+	int len;
+	int temp_bpw = bpw;
+	int idx_start = msb_to_lsb ? bpw - 1 : 0;
+	int idx = idx_start;
+	int idx_delta = msb_to_lsb ? -BITS_PER_BYTE : BITS_PER_BYTE;
+	int ceil_bpw = ALIGN(bpw, BITS_PER_BYTE);
+	int iter = (ceil_bpw * pack_words) / BITS_PER_BYTE;
+	int i;
+
+	if (iter <= 0 || iter > NUM_PACKING_VECTORS)
+		return;
+
+	for (i = 0; i < iter; i++) {
+		len = min_t(int, temp_bpw, BITS_PER_BYTE) - 1;
+		cfg[i] = idx << PACKING_START_SHIFT;
+		cfg[i] |= msb_to_lsb << PACKING_DIR_SHIFT;
+		cfg[i] |= len << PACKING_LEN_SHIFT;
+
+		if (temp_bpw <= BITS_PER_BYTE) {
+			idx = ((i + 1) * BITS_PER_BYTE) + idx_start;
+			temp_bpw = bpw;
+		} else {
+			idx = idx + idx_delta;
+			temp_bpw = temp_bpw - BITS_PER_BYTE;
+		}
+	}
+	cfg[iter - 1] |= PACKING_STOP_BIT;
+	cfg0 = cfg[0] | (cfg[1] << PACKING_VECTOR_SHIFT);
+	cfg1 = cfg[2] | (cfg[3] << PACKING_VECTOR_SHIFT);
+
+	if (tx_cfg) {
+		writel_relaxed(cfg0, se->base + SE_GENI_TX_PACKING_CFG0);
+		writel_relaxed(cfg1, se->base + SE_GENI_TX_PACKING_CFG1);
+	}
+	if (rx_cfg) {
+		writel_relaxed(cfg0, se->base + SE_GENI_RX_PACKING_CFG0);
+		writel_relaxed(cfg1, se->base + SE_GENI_RX_PACKING_CFG1);
+	}
+
+	/*
+	 * Number of protocol words in each FIFO entry
+	 * 0 - 4x8, four words in each entry, max word size of 8 bits
+	 * 1 - 2x16, two words in each entry, max word size of 16 bits
+	 * 2 - 1x32, one word in each entry, max word size of 32 bits
+	 * 3 - undefined
+	 */
+	if (pack_words || bpw == 32)
+		writel_relaxed(bpw / 16, se->base + SE_GENI_BYTE_GRAN);
+}
+EXPORT_SYMBOL(geni_se_config_packing);
+
+static void geni_se_clks_off(struct geni_se *se)
+{
+	struct geni_wrapper *wrapper = se->wrapper;
+
+	clk_disable_unprepare(se->clk);
+	clk_bulk_disable_unprepare(ARRAY_SIZE(wrapper->ahb_clks),
+						wrapper->ahb_clks);
+}
+
+/**
+ * geni_se_resources_off() - Turn off resources associated with the serial
+ *                           engine
+ * @se:	Pointer to the concerned serial engine.
+ *
+ * Return: 0 on success, standard Linux error codes on failure/error.
+ */
+int geni_se_resources_off(struct geni_se *se)
+{
+	int ret;
+
+	ret = pinctrl_pm_select_sleep_state(se->dev);
+	if (ret)
+		return ret;
+
+	geni_se_clks_off(se);
+	return 0;
+}
+EXPORT_SYMBOL(geni_se_resources_off);
+
+static int geni_se_clks_on(struct geni_se *se)
+{
+	int ret;
+	struct geni_wrapper *wrapper = se->wrapper;
+
+	ret = clk_bulk_prepare_enable(ARRAY_SIZE(wrapper->ahb_clks),
+						wrapper->ahb_clks);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(se->clk);
+	if (ret)
+		clk_bulk_disable_unprepare(ARRAY_SIZE(wrapper->ahb_clks),
+							wrapper->ahb_clks);
+	return ret;
+}
+
+/**
+ * geni_se_resources_on() - Turn on resources associated with the serial
+ *                          engine
+ * @se:	Pointer to the concerned serial engine.
+ *
+ * Return: 0 on success, standard Linux error codes on failure/error.
+ */
+int geni_se_resources_on(struct geni_se *se)
+{
+	int ret;
+
+	ret = geni_se_clks_on(se);
+	if (ret)
+		return ret;
+
+	ret = pinctrl_pm_select_default_state(se->dev);
+	if (ret)
+		geni_se_clks_off(se);
+
+	return ret;
+}
+EXPORT_SYMBOL(geni_se_resources_on);
+
+/**
+ * geni_se_clk_tbl_get() - Get the clock table to program DFS
+ * @se:		Pointer to the concerned serial engine.
+ * @tbl:	Table in which the output is returned.
+ *
+ * This function is called by the protocol drivers to determine the different
+ * clock frequencies supported by serial engine core clock. The protocol
+ * drivers use the output to determine the clock frequency index to be
+ * programmed into DFS.
+ *
+ * Return: number of valid performance levels in the table on success,
+ *	   standard Linux error codes on failure.
+ */
+int geni_se_clk_tbl_get(struct geni_se *se, unsigned long **tbl)
+{
+	unsigned long freq = 0;
+	int i;
+
+	if (se->clk_perf_tbl) {
+		*tbl = se->clk_perf_tbl;
+		return se->num_clk_levels;
+	}
+
+	se->clk_perf_tbl = devm_kcalloc(se->dev, MAX_CLK_PERF_LEVEL,
+					sizeof(*se->clk_perf_tbl),
+					GFP_KERNEL);
+	if (!se->clk_perf_tbl)
+		return -ENOMEM;
+
+	for (i = 0; i < MAX_CLK_PERF_LEVEL; i++) {
+		freq = clk_round_rate(se->clk, freq + 1);
+		if (!freq || freq == se->clk_perf_tbl[i - 1])
+			break;
+		se->clk_perf_tbl[i] = freq;
+	}
+	se->num_clk_levels = i;
+	*tbl = se->clk_perf_tbl;
+	return se->num_clk_levels;
+}
+EXPORT_SYMBOL(geni_se_clk_tbl_get);
+
+/**
+ * geni_se_clk_freq_match() - Get the matching or closest SE clock frequency
+ * @se:		Pointer to the concerned serial engine.
+ * @req_freq:	Requested clock frequency.
+ * @index:	Index of the resultant frequency in the table.
+ * @res_freq:	Resultant frequency which matches or is closer to the
+ *		requested frequency.
+ * @exact:	Flag to indicate exact multiple requirement of the requested
+ *		frequency.
+ *
+ * This function is called by the protocol drivers to determine the matching
+ * or exact multiple of the requested frequency, as provided by the serial
+ * engine clock in order to meet the performance requirements. If there is
+ * no matching or exact multiple of the requested frequency found, then it
+ * selects the closest floor frequency, if exact flag is not set.
+ *
+ * Return: 0 on success, standard Linux error codes on failure.
+ */
+int geni_se_clk_freq_match(struct geni_se *se, unsigned long req_freq,
+			   unsigned int *index, unsigned long *res_freq,
+			   bool exact)
+{
+	unsigned long *tbl;
+	int num_clk_levels;
+	int i;
+
+	num_clk_levels = geni_se_clk_tbl_get(se, &tbl);
+	if (num_clk_levels < 0)
+		return num_clk_levels;
+
+	if (num_clk_levels == 0)
+		return -EINVAL;
+
+	*res_freq = 0;
+	for (i = 0; i < num_clk_levels; i++) {
+		if (!(tbl[i] % req_freq)) {
+			*index = i;
+			*res_freq = tbl[i];
+			return 0;
+		}
+
+		if (!(*res_freq) || ((tbl[i] > *res_freq) &&
+				     (tbl[i] < req_freq))) {
+			*index = i;
+			*res_freq = tbl[i];
+		}
+	}
+
+	if (exact)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(geni_se_clk_freq_match);
+
+#define GENI_SE_DMA_DONE_EN BIT(0)
+#define GENI_SE_DMA_EOT_EN BIT(1)
+#define GENI_SE_DMA_AHB_ERR_EN BIT(2)
+#define GENI_SE_DMA_EOT_BUF BIT(0)
+/**
+ * geni_se_tx_dma_prep() - Prepare the serial engine for TX DMA transfer
+ * @se:			Pointer to the concerned serial engine.
+ * @buf:		Pointer to the TX buffer.
+ * @len:		Length of the TX buffer.
+ * @iova:		Pointer to store the mapped DMA address.
+ *
+ * This function is used to prepare the buffers for DMA TX.
+ *
+ * Return: 0 on success, standard Linux error codes on failure.
+ */
+int geni_se_tx_dma_prep(struct geni_se *se, void *buf, size_t len,
+			dma_addr_t *iova)
+{
+	struct geni_wrapper *wrapper = se->wrapper;
+	u32 val;
+
+	*iova = dma_map_single(wrapper->dev, buf, len, DMA_TO_DEVICE);
+	if (dma_mapping_error(wrapper->dev, *iova))
+		return -EIO;
+
+	val = GENI_SE_DMA_DONE_EN;
+	val |= GENI_SE_DMA_EOT_EN;
+	val |= GENI_SE_DMA_AHB_ERR_EN;
+	writel_relaxed(val, se->base + SE_DMA_TX_IRQ_EN_SET);
+	writel_relaxed(lower_32_bits(*iova), se->base + SE_DMA_TX_PTR_L);
+	writel_relaxed(upper_32_bits(*iova), se->base + SE_DMA_TX_PTR_H);
+	writel_relaxed(GENI_SE_DMA_EOT_BUF, se->base + SE_DMA_TX_ATTR);
+	writel_relaxed(len, se->base + SE_DMA_TX_LEN);
+	return 0;
+}
+EXPORT_SYMBOL(geni_se_tx_dma_prep);
+
+/**
+ * geni_se_rx_dma_prep() - Prepare the serial engine for RX DMA transfer
+ * @se:			Pointer to the concerned serial engine.
+ * @buf:		Pointer to the RX buffer.
+ * @len:		Length of the RX buffer.
+ * @iova:		Pointer to store the mapped DMA address.
+ *
+ * This function is used to prepare the buffers for DMA RX.
+ *
+ * Return: 0 on success, standard Linux error codes on failure.
+ */
+int geni_se_rx_dma_prep(struct geni_se *se, void *buf, size_t len,
+			dma_addr_t *iova)
+{
+	struct geni_wrapper *wrapper = se->wrapper;
+	u32 val;
+
+	*iova = dma_map_single(wrapper->dev, buf, len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(wrapper->dev, *iova))
+		return -EIO;
+
+	val = GENI_SE_DMA_DONE_EN;
+	val |= GENI_SE_DMA_EOT_EN;
+	val |= GENI_SE_DMA_AHB_ERR_EN;
+	writel_relaxed(val, se->base + SE_DMA_RX_IRQ_EN_SET);
+	writel_relaxed(lower_32_bits(*iova), se->base + SE_DMA_RX_PTR_L);
+	writel_relaxed(upper_32_bits(*iova), se->base + SE_DMA_RX_PTR_H);
+	/* RX does not have EOT buffer type bit. So just reset RX_ATTR */
+	writel_relaxed(0, se->base + SE_DMA_RX_ATTR);
+	writel_relaxed(len, se->base + SE_DMA_RX_LEN);
+	return 0;
+}
+EXPORT_SYMBOL(geni_se_rx_dma_prep);
+
+/**
+ * geni_se_tx_dma_unprep() - Unprepare the serial engine after TX DMA transfer
+ * @se:			Pointer to the concerned serial engine.
+ * @iova:		DMA address of the TX buffer.
+ * @len:		Length of the TX buffer.
+ *
+ * This function is used to unprepare the DMA buffers after DMA TX.
+ */
+void geni_se_tx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
+{
+	struct geni_wrapper *wrapper = se->wrapper;
+
+	if (iova && !dma_mapping_error(wrapper->dev, iova))
+		dma_unmap_single(wrapper->dev, iova, len, DMA_TO_DEVICE);
+}
+EXPORT_SYMBOL(geni_se_tx_dma_unprep);
+
+/**
+ * geni_se_rx_dma_unprep() - Unprepare the serial engine after RX DMA transfer
+ * @se:			Pointer to the concerned serial engine.
+ * @iova:		DMA address of the RX buffer.
+ * @len:		Length of the RX buffer.
+ *
+ * This function is used to unprepare the DMA buffers after DMA RX.
+ */
+void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
+{
+	struct geni_wrapper *wrapper = se->wrapper;
+
+	if (iova && !dma_mapping_error(wrapper->dev, iova))
+		dma_unmap_single(wrapper->dev, iova, len, DMA_FROM_DEVICE);
+}
+EXPORT_SYMBOL(geni_se_rx_dma_unprep);
+
+static int geni_se_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct geni_wrapper *wrapper;
+	int ret;
+
+	wrapper = devm_kzalloc(dev, sizeof(*wrapper), GFP_KERNEL);
+	if (!wrapper)
+		return -ENOMEM;
+
+	wrapper->dev = dev;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	wrapper->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(wrapper->base))
+		return PTR_ERR(wrapper->base);
+
+	wrapper->ahb_clks[0].id = "m-ahb";
+	wrapper->ahb_clks[1].id = "s-ahb";
+	ret = devm_clk_bulk_get(dev, NUM_AHB_CLKS, wrapper->ahb_clks);
+	if (ret) {
+		dev_err(dev, "Err getting AHB clks %d\n", ret);
+		return ret;
+	}
+
+	dev_set_drvdata(dev, wrapper);
+	dev_dbg(dev, "GENI SE Driver probed\n");
+	return devm_of_platform_populate(dev);
+}
+
+static const struct of_device_id geni_se_dt_match[] = {
+	{ .compatible = "qcom,geni-se-qup", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, geni_se_dt_match);
+
+static struct platform_driver geni_se_driver = {
+	.driver = {
+		.name = "geni_se_qup",
+		.of_match_table = geni_se_dt_match,
+	},
+	.probe = geni_se_probe,
+};
+module_platform_driver(geni_se_driver);
+
+MODULE_DESCRIPTION("GENI Serial Engine Driver");
+MODULE_LICENSE("GPL v2");