serial: qcom: add support for GENI serial driver
authorDzmitry Sankouski <dsankouski@gmail.com>
Sun, 17 Oct 2021 10:44:27 +0000 (13:44 +0300)
committerTom Rini <trini@konsulko.com>
Sun, 31 Oct 2021 12:46:44 +0000 (08:46 -0400)
Generic Interface (GENI) Serial Engine (SE) based uart
can be found on newer qualcomm SOCs, starting from SDM845.
Tested on Samsung SM-G9600(starqltechn)
by chain-loading u-boot with stock bootloader.

Signed-off-by: Dzmitry Sankouski <dsankouski@gmail.com>
Cc: Ramon Fried <rfried.dev@gmail.com>
Cc: Tom Rini <trini@konsulko.com>
MAINTAINERS
doc/device-tree-bindings/serial/msm-geni-serial.txt [new file with mode: 0644]
drivers/serial/Kconfig
drivers/serial/Makefile
drivers/serial/serial_msm_geni.c [new file with mode: 0644]

index 4ed72ae..1b3f6c5 100644 (file)
@@ -400,6 +400,7 @@ F:  drivers/gpio/msm_gpio.c
 F:     drivers/mmc/msm_sdhci.c
 F:     drivers/phy/msm8916-usbh-phy.c
 F:     drivers/serial/serial_msm.c
+F:     drivers/serial/serial_msm_geni.c
 F:     drivers/smem/msm_smem.c
 F:     drivers/usb/host/ehci-msm.c
 
diff --git a/doc/device-tree-bindings/serial/msm-geni-serial.txt b/doc/device-tree-bindings/serial/msm-geni-serial.txt
new file mode 100644 (file)
index 0000000..9eadc25
--- /dev/null
@@ -0,0 +1,6 @@
+Qualcomm GENI UART
+
+Required properties:
+- compatible: must be "qcom,msm-geni-uart"
+- reg: start address and size of the registers
+- clock: interface clock (must accept baudrate as a frequency)
index 7ee1290..6c8fdda 100644 (file)
@@ -296,6 +296,14 @@ config DEBUG_UART_S5P
          will need to provide parameters to make this work. The driver will
          be available until the real driver-model serial is running.
 
+config DEBUG_UART_MSM_GENI
+       bool "Qualcomm snapdragon"
+       depends on ARCH_SNAPDRAGON
+       help
+         Select this to enable a debug UART using the serial_msm driver. You
+         will need to provide parameters to make this work. The driver will
+         be available until the real driver-model serial is running.
+
 config DEBUG_UART_MESON
        bool "Amlogic Meson"
        depends on MESON_SERIAL
@@ -801,6 +809,16 @@ config MSM_SERIAL
          for example APQ8016 and MSM8916.
          Single baudrate is supported in current implementation (115200).
 
+config MSM_GENI_SERIAL
+       bool "Qualcomm on-chip GENI UART"
+       help
+         Support UART based on Generic Interface (GENI) Serial Engine (SE),
+         used on Qualcomm Snapdragon SoCs. Should support all qualcomm SOCs
+         with Qualcomm Universal Peripheral (QUP) Wrapper cores,
+         i.e. newer ones, starting from SDM845.
+         Driver works in FIFO mode.
+         Multiple baudrates supported.
+
 config OCTEON_SERIAL_BOOTCMD
        bool "MIPS Octeon PCI remote bootcmd input"
        depends on ARCH_OCTEON
index 4edd2aa..8168af6 100644 (file)
@@ -63,6 +63,7 @@ obj-$(CONFIG_PIC32_SERIAL) += serial_pic32.o
 obj-$(CONFIG_BCM283X_MU_SERIAL) += serial_bcm283x_mu.o
 obj-$(CONFIG_BCM283X_PL011_SERIAL) += serial_bcm283x_pl011.o
 obj-$(CONFIG_MSM_SERIAL) += serial_msm.o
+obj-$(CONFIG_MSM_GENI_SERIAL) += serial_msm_geni.o
 obj-$(CONFIG_MVEBU_A3700_UART) += serial_mvebu_a3700.o
 obj-$(CONFIG_MPC8XX_CONS) += serial_mpc8xx.o
 obj-$(CONFIG_NULLDEV_SERIAL) += serial_nulldev.o
diff --git a/drivers/serial/serial_msm_geni.c b/drivers/serial/serial_msm_geni.c
new file mode 100644 (file)
index 0000000..3e255a9
--- /dev/null
@@ -0,0 +1,613 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Qualcomm GENI serial engine UART driver
+ *
+ * (C) Copyright 2021 Dzmitry Sankouski <dsankouski@gmail.com>
+ *
+ * Based on Linux driver.
+ */
+
+#include <asm/io.h>
+#include <clk.h>
+#include <common.h>
+#include <dm.h>
+#include <dm/pinctrl.h>
+#include <errno.h>
+#include <linux/compiler.h>
+#include <log.h>
+#include <linux/delay.h>
+#include <malloc.h>
+#include <serial.h>
+#include <watchdog.h>
+#include <linux/bug.h>
+
+#define UART_OVERSAMPLING      32
+#define STALE_TIMEOUT  160
+
+#define USEC_PER_SEC   1000000L
+
+/* Registers*/
+#define GENI_FORCE_DEFAULT_REG 0x20
+#define GENI_SER_M_CLK_CFG     0x48
+#define GENI_SER_S_CLK_CFG     0x4C
+#define SE_HW_PARAM_0  0xE24
+#define SE_GENI_STATUS 0x40
+#define SE_GENI_S_CMD0 0x630
+#define SE_GENI_S_CMD_CTRL_REG 0x634
+#define SE_GENI_S_IRQ_CLEAR    0x648
+#define SE_GENI_S_IRQ_STATUS   0x640
+#define SE_GENI_S_IRQ_EN       0x644
+#define SE_GENI_M_CMD0 0x600
+#define SE_GENI_M_CMD_CTRL_REG 0x604
+#define SE_GENI_M_IRQ_CLEAR    0x618
+#define SE_GENI_M_IRQ_STATUS   0x610
+#define SE_GENI_M_IRQ_EN       0x614
+#define SE_GENI_TX_FIFOn       0x700
+#define SE_GENI_RX_FIFOn       0x780
+#define SE_GENI_TX_FIFO_STATUS 0x800
+#define SE_GENI_RX_FIFO_STATUS 0x804
+#define SE_GENI_TX_WATERMARK_REG       0x80C
+#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_UART_RX_STALE_CNT   0x294
+#define SE_UART_TX_TRANS_LEN   0x270
+#define SE_UART_TX_STOP_BIT_LEN        0x26c
+#define SE_UART_TX_WORD_LEN    0x268
+#define SE_UART_RX_WORD_LEN    0x28c
+#define SE_UART_TX_TRANS_CFG   0x25c
+#define SE_UART_TX_PARITY_CFG  0x2a4
+#define SE_UART_RX_TRANS_CFG   0x280
+#define SE_UART_RX_PARITY_CFG  0x2a8
+
+#define M_TX_FIFO_WATERMARK_EN (BIT(30))
+#define DEF_TX_WM      2
+/* GENI_FORCE_DEFAULT_REG fields */
+#define FORCE_DEFAULT  (BIT(0))
+
+#define S_CMD_ABORT_EN (BIT(5))
+
+#define UART_START_READ        0x1
+
+/* GENI_M_CMD_CTRL_REG */
+#define M_GENI_CMD_CANCEL      (BIT(2))
+#define M_GENI_CMD_ABORT       (BIT(1))
+#define M_GENI_DISABLE (BIT(0))
+
+#define M_CMD_ABORT_EN (BIT(5))
+#define M_CMD_DONE_EN  (BIT(0))
+#define M_CMD_DONE_DISABLE_MASK        (~M_CMD_DONE_EN)
+
+#define S_GENI_CMD_ABORT       (BIT(1))
+
+/* GENI_S_CMD0 fields */
+#define S_OPCODE_MSK   (GENMASK(31, 27))
+#define S_PARAMS_MSK   (GENMASK(26, 0))
+
+/* GENI_STATUS fields */
+#define M_GENI_CMD_ACTIVE      (BIT(0))
+#define S_GENI_CMD_ACTIVE      (BIT(12))
+#define M_CMD_DONE_EN  (BIT(0))
+#define S_CMD_DONE_EN  (BIT(0))
+
+#define M_OPCODE_SHIFT 27
+#define S_OPCODE_SHIFT 27
+#define M_TX_FIFO_WATERMARK_EN (BIT(30))
+#define UART_START_TX  0x1
+#define UART_CTS_MASK  (BIT(1))
+#define M_SEC_IRQ_EN   (BIT(31))
+#define TX_FIFO_WC_MSK (GENMASK(27, 0))
+#define RX_FIFO_WC_MSK (GENMASK(24, 0))
+
+#define S_RX_FIFO_WATERMARK_EN (BIT(26))
+#define S_RX_FIFO_LAST_EN      (BIT(27))
+#define M_RX_FIFO_WATERMARK_EN (BIT(26))
+#define M_RX_FIFO_LAST_EN      (BIT(27))
+
+/* GENI_SER_M_CLK_CFG/GENI_SER_S_CLK_CFG */
+#define SER_CLK_EN     (BIT(0))
+#define CLK_DIV_MSK    (GENMASK(15, 4))
+#define CLK_DIV_SHFT   4
+
+/* SE_HW_PARAM_0 fields */
+#define TX_FIFO_WIDTH_MSK      (GENMASK(29, 24))
+#define TX_FIFO_WIDTH_SHFT     24
+#define TX_FIFO_DEPTH_MSK      (GENMASK(21, 16))
+#define TX_FIFO_DEPTH_SHFT     16
+
+/*
+ * Predefined packing configuration of the serial engine (CFG0, CFG1 regs)
+ * for uart mode.
+ *
+ * Defines following configuration:
+ * - Bits of data per transfer word             8
+ * - Number of words per fifo element           4
+ * - Transfer from MSB to LSB or vice-versa     false
+ */
+#define UART_PACKING_CFG0   0xf
+#define UART_PACKING_CFG1   0x0
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct msm_serial_data {
+       phys_addr_t base;
+       u32 baud;
+};
+
+unsigned long root_freq[] = {7372800,  14745600, 19200000, 29491200,
+                                        32000000, 48000000, 64000000, 80000000,
+                                        96000000, 100000000};
+
+/**
+ * get_clk_cfg() - Get clock rate to apply on clock supplier.
+ * @clk_freq:  Desired clock frequency after build-in divider.
+ *
+ * Return: frequency, supported by clock supplier, multiple of clk_freq.
+ */
+static int get_clk_cfg(unsigned long clk_freq)
+{
+       for (int i = 0; i < ARRAY_SIZE(root_freq); i++) {
+               if (!(root_freq[i] % clk_freq))
+                       return root_freq[i];
+       }
+       return 0;
+}
+
+/**
+ * get_clk_div_rate() - Find clock supplier frequency, and calculate divisor.
+ * @baud:              Baudrate.
+ * @sampling_rate:     Clock ticks per character.
+ * @clk_div:       Pointer to calculated divisor.
+ *
+ * This function searches for suitable frequency for clock supplier,
+ * calculates divisor for internal divider, based on found frequency,
+ * and stores divisor under clk_div pointer.
+ *
+ * Return: frequency, supported by clock supplier, multiple of clk_freq.
+ */
+static int get_clk_div_rate(u32 baud,
+                                                       u64 sampling_rate, u32 *clk_div)
+{
+       unsigned long ser_clk;
+       unsigned long desired_clk;
+
+       desired_clk = baud * sampling_rate;
+       ser_clk = get_clk_cfg(desired_clk);
+       if (!ser_clk) {
+               pr_err("%s: Can't find matching DFS entry for baud %d\n",
+                                                               __func__, baud);
+               return ser_clk;
+       }
+
+       *clk_div = ser_clk / desired_clk;
+       return ser_clk;
+}
+
+static int geni_serial_set_clock_rate(struct udevice *dev, u64 rate)
+{
+       struct clk *clk;
+       int ret;
+
+       clk = devm_clk_get(dev, "se-clk");
+       if (!clk)
+               return -EINVAL;
+
+       ret = clk_set_rate(clk, rate);
+       return ret;
+}
+
+/**
+ * geni_se_get_tx_fifo_depth() - Get the TX fifo depth of the serial engine
+ * @base:      Pointer to the concerned serial engine.
+ *
+ * This function is used to get the depth i.e. number of elements in the
+ * TX fifo of the serial engine.
+ *
+ * Return: TX fifo depth in units of FIFO words.
+ */
+static inline u32 geni_se_get_tx_fifo_depth(long base)
+{
+       u32 tx_fifo_depth;
+
+       tx_fifo_depth = ((readl(base + SE_HW_PARAM_0) & TX_FIFO_DEPTH_MSK) >>
+                        TX_FIFO_DEPTH_SHFT);
+       return tx_fifo_depth;
+}
+
+/**
+ * geni_se_get_tx_fifo_width() - Get the TX fifo width of the serial engine
+ * @base:      Pointer to the concerned serial engine.
+ *
+ * This function is used to get the width i.e. word size per element in the
+ * TX fifo of the serial engine.
+ *
+ * Return: TX fifo width in bits
+ */
+static inline u32 geni_se_get_tx_fifo_width(long base)
+{
+       u32 tx_fifo_width;
+
+       tx_fifo_width = ((readl(base + SE_HW_PARAM_0) & TX_FIFO_WIDTH_MSK) >>
+                        TX_FIFO_WIDTH_SHFT);
+       return tx_fifo_width;
+}
+
+static inline void geni_serial_baud(phys_addr_t base_address, u32 clk_div,
+                                                                       int baud)
+{
+       u32 s_clk_cfg = 0;
+
+       s_clk_cfg |= SER_CLK_EN;
+       s_clk_cfg |= (clk_div << CLK_DIV_SHFT);
+
+       writel(s_clk_cfg, base_address + GENI_SER_M_CLK_CFG);
+       writel(s_clk_cfg, base_address + GENI_SER_S_CLK_CFG);
+}
+
+int msm_serial_setbrg(struct udevice *dev, int baud)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       priv->baud = baud;
+       u32 clk_div;
+       u64 clk_rate;
+
+       clk_rate = get_clk_div_rate(baud, UART_OVERSAMPLING, &clk_div);
+       geni_serial_set_clock_rate(dev, clk_rate);
+       geni_serial_baud(priv->base, clk_div, baud);
+
+       return 0;
+}
+
+/**
+ * qcom_geni_serial_poll_bit() - Poll reg bit until desired value or timeout.
+ * @base:      Pointer to the concerned serial engine.
+ * @offset:    Offset to register address.
+ * @field:     AND bitmask for desired bit.
+ * @set:       Desired bit value.
+ *
+ * This function is used to get the width i.e. word size per element in the
+ * TX fifo of the serial engine.
+ *
+ * Return: true, when register bit equals desired value, false, when timeout
+ * reached.
+ */
+static bool qcom_geni_serial_poll_bit(const struct udevice *dev, int offset,
+                                         int field, bool set)
+{
+       u32 reg;
+       struct msm_serial_data *priv = dev_get_priv(dev);
+       unsigned int baud;
+       unsigned int tx_fifo_depth;
+       unsigned int tx_fifo_width;
+       unsigned int fifo_bits;
+       unsigned long timeout_us = 10000;
+
+       baud = 115200;
+
+       if (priv) {
+               baud = priv->baud;
+               if (!baud)
+                       baud = 115200;
+               tx_fifo_depth = geni_se_get_tx_fifo_depth(priv->base);
+               tx_fifo_width = geni_se_get_tx_fifo_width(priv->base);
+               fifo_bits = tx_fifo_depth * tx_fifo_width;
+               /*
+                * Total polling iterations based on FIFO worth of bytes to be
+                * sent at current baud. Add a little fluff to the wait.
+                */
+               timeout_us = ((fifo_bits * USEC_PER_SEC) / baud) + 500;
+       }
+
+       timeout_us = DIV_ROUND_UP(timeout_us, 10) * 10;
+       while (timeout_us) {
+               reg = readl(priv->base + offset);
+               if ((bool)(reg & field) == set)
+                       return true;
+               udelay(10);
+               timeout_us -= 10;
+       }
+       return false;
+}
+
+static void qcom_geni_serial_setup_tx(u64 base, u32 xmit_size)
+{
+       u32 m_cmd;
+
+       writel(xmit_size, base + SE_UART_TX_TRANS_LEN);
+       m_cmd = UART_START_TX << M_OPCODE_SHIFT;
+       writel(m_cmd, base + SE_GENI_M_CMD0);
+}
+
+static inline void qcom_geni_serial_poll_tx_done(const struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+       int done = 0;
+       u32 irq_clear = M_CMD_DONE_EN;
+
+       done = qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
+                                        M_CMD_DONE_EN, true);
+       if (!done) {
+               writel(M_GENI_CMD_ABORT, priv->base + SE_GENI_M_CMD_CTRL_REG);
+               irq_clear |= M_CMD_ABORT_EN;
+               qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
+                                         M_CMD_ABORT_EN, true);
+       }
+       writel(irq_clear, priv->base + SE_GENI_M_IRQ_CLEAR);
+}
+
+static u32 qcom_geni_serial_tx_empty(u64 base)
+{
+       return !readl(base + SE_GENI_TX_FIFO_STATUS);
+}
+
+/**
+ * geni_se_setup_s_cmd() - Setup the secondary sequencer
+ * @se:                Pointer to the concerned serial engine.
+ * @cmd:       Command/Operation to setup in the secondary sequencer.
+ * @params:    Parameter for the sequencer command.
+ *
+ * This function is used to configure the secondary sequencer with the
+ * command and its associated parameters.
+ */
+static inline void geni_se_setup_s_cmd(u64 base, u32 cmd, u32 params)
+{
+       u32 s_cmd;
+
+       s_cmd = readl(base + SE_GENI_S_CMD0);
+       s_cmd &= ~(S_OPCODE_MSK | S_PARAMS_MSK);
+       s_cmd |= (cmd << S_OPCODE_SHIFT);
+       s_cmd |= (params & S_PARAMS_MSK);
+       writel(s_cmd, base + SE_GENI_S_CMD0);
+}
+
+static void qcom_geni_serial_start_tx(u64 base)
+{
+       u32 irq_en;
+       u32 status;
+
+       status = readl(base + SE_GENI_STATUS);
+       if (status & M_GENI_CMD_ACTIVE)
+               return;
+
+       if (!qcom_geni_serial_tx_empty(base))
+               return;
+
+       irq_en = readl(base + SE_GENI_M_IRQ_EN);
+       irq_en |= M_TX_FIFO_WATERMARK_EN | M_CMD_DONE_EN;
+
+       writel(DEF_TX_WM, base + SE_GENI_TX_WATERMARK_REG);
+       writel(irq_en, base + SE_GENI_M_IRQ_EN);
+}
+
+static void qcom_geni_serial_start_rx(struct udevice *dev)
+{
+       u32 status;
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       status = readl(priv->base + SE_GENI_STATUS);
+
+       geni_se_setup_s_cmd(priv->base, UART_START_READ, 0);
+
+       setbits_le32(priv->base + SE_GENI_S_IRQ_EN, S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
+       setbits_le32(priv->base + SE_GENI_M_IRQ_EN, M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
+}
+
+static void qcom_geni_serial_abort_rx(struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       u32 irq_clear = S_CMD_DONE_EN | S_CMD_ABORT_EN;
+
+       writel(S_GENI_CMD_ABORT, priv->base + SE_GENI_S_CMD_CTRL_REG);
+       qcom_geni_serial_poll_bit(dev, SE_GENI_S_CMD_CTRL_REG,
+                                       S_GENI_CMD_ABORT, false);
+       writel(irq_clear, priv->base + SE_GENI_S_IRQ_CLEAR);
+       writel(FORCE_DEFAULT, priv->base + GENI_FORCE_DEFAULT_REG);
+}
+
+static void msm_geni_serial_setup_rx(struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       qcom_geni_serial_abort_rx(dev);
+
+       writel(UART_PACKING_CFG0, priv->base + SE_GENI_RX_PACKING_CFG0);
+       writel(UART_PACKING_CFG1, priv->base + SE_GENI_RX_PACKING_CFG1);
+
+       geni_se_setup_s_cmd(priv->base, UART_START_READ, 0);
+
+       setbits_le32(priv->base + SE_GENI_S_IRQ_EN, S_RX_FIFO_WATERMARK_EN | S_RX_FIFO_LAST_EN);
+       setbits_le32(priv->base + SE_GENI_M_IRQ_EN, M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN);
+}
+
+static int msm_serial_putc(struct udevice *dev, const char ch)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       writel(DEF_TX_WM, priv->base + SE_GENI_TX_WATERMARK_REG);
+       qcom_geni_serial_setup_tx(priv->base, 1);
+
+       qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS,
+                                 M_TX_FIFO_WATERMARK_EN, true);
+
+       writel(ch, priv->base + SE_GENI_TX_FIFOn);
+       writel(M_TX_FIFO_WATERMARK_EN, priv->base + SE_GENI_M_IRQ_CLEAR);
+
+       qcom_geni_serial_poll_tx_done(dev);
+
+       return 0;
+}
+
+static int msm_serial_getc(struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+       u32 rx_fifo;
+       u32 m_irq_status;
+       u32 s_irq_status;
+
+       writel(1 << S_OPCODE_SHIFT, priv->base + SE_GENI_S_CMD0);
+
+       qcom_geni_serial_poll_bit(dev, SE_GENI_M_IRQ_STATUS, M_SEC_IRQ_EN,
+                                 true);
+
+       m_irq_status = readl(priv->base + SE_GENI_M_IRQ_STATUS);
+       s_irq_status = readl(priv->base + SE_GENI_S_IRQ_STATUS);
+       writel(m_irq_status, priv->base + SE_GENI_M_IRQ_CLEAR);
+       writel(s_irq_status, priv->base + SE_GENI_S_IRQ_CLEAR);
+       qcom_geni_serial_poll_bit(dev, SE_GENI_RX_FIFO_STATUS, RX_FIFO_WC_MSK,
+                                 true);
+
+       if (!readl(priv->base + SE_GENI_RX_FIFO_STATUS))
+               return 0;
+
+       rx_fifo = readl(priv->base + SE_GENI_RX_FIFOn);
+       return rx_fifo & 0xff;
+}
+
+static int msm_serial_pending(struct udevice *dev, bool input)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       if (input)
+               return readl(priv->base + SE_GENI_RX_FIFO_STATUS) &
+                          RX_FIFO_WC_MSK;
+       else
+               return readl(priv->base + SE_GENI_TX_FIFO_STATUS) &
+                          TX_FIFO_WC_MSK;
+
+       return 0;
+}
+
+static const struct dm_serial_ops msm_serial_ops = {
+       .putc = msm_serial_putc,
+       .pending = msm_serial_pending,
+       .getc = msm_serial_getc,
+       .setbrg = msm_serial_setbrg,
+};
+
+static inline void geni_serial_init(struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+       phys_addr_t base_address = priv->base;
+       u32 tx_trans_cfg;
+       u32 tx_parity_cfg = 0; /* Disable Tx Parity */
+       u32 rx_trans_cfg = 0;
+       u32 rx_parity_cfg = 0; /* Disable Rx Parity */
+       u32 stop_bit_len = 0;  /* Default stop bit length - 1 bit */
+       u32 bits_per_char;
+
+       /*
+        * Ignore Flow control.
+        * n = 8.
+        */
+       tx_trans_cfg = UART_CTS_MASK;
+       bits_per_char = BITS_PER_BYTE;
+
+       /*
+        * Make an unconditional cancel on the main sequencer to reset
+        * it else we could end up in data loss scenarios.
+        */
+       qcom_geni_serial_poll_tx_done(dev);
+       qcom_geni_serial_abort_rx(dev);
+
+       writel(UART_PACKING_CFG0, base_address + SE_GENI_TX_PACKING_CFG0);
+       writel(UART_PACKING_CFG1, base_address + SE_GENI_TX_PACKING_CFG1);
+       writel(UART_PACKING_CFG0, base_address + SE_GENI_RX_PACKING_CFG0);
+       writel(UART_PACKING_CFG1, base_address + SE_GENI_RX_PACKING_CFG1);
+
+       writel(tx_trans_cfg, base_address + SE_UART_TX_TRANS_CFG);
+       writel(tx_parity_cfg, base_address + SE_UART_TX_PARITY_CFG);
+       writel(rx_trans_cfg, base_address + SE_UART_RX_TRANS_CFG);
+       writel(rx_parity_cfg, base_address + SE_UART_RX_PARITY_CFG);
+       writel(bits_per_char, base_address + SE_UART_TX_WORD_LEN);
+       writel(bits_per_char, base_address + SE_UART_RX_WORD_LEN);
+       writel(stop_bit_len, base_address + SE_UART_TX_STOP_BIT_LEN);
+}
+
+static int msm_serial_probe(struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       /* No need to reinitialize the UART after relocation */
+       if (gd->flags & GD_FLG_RELOC)
+               return 0;
+
+       geni_serial_init(dev);
+       msm_geni_serial_setup_rx(dev);
+       qcom_geni_serial_start_rx(dev);
+       qcom_geni_serial_start_tx(priv->base);
+
+       return 0;
+}
+
+static int msm_serial_ofdata_to_platdata(struct udevice *dev)
+{
+       struct msm_serial_data *priv = dev_get_priv(dev);
+
+       priv->base = dev_read_addr(dev);
+       if (priv->base == FDT_ADDR_T_NONE)
+               return -EINVAL;
+
+       return 0;
+}
+
+static const struct udevice_id msm_serial_ids[] = {
+       {.compatible = "qcom,msm-geni-uart"}, {}};
+
+U_BOOT_DRIVER(serial_msm_geni) = {
+       .name = "serial_msm_geni",
+       .id = UCLASS_SERIAL,
+       .of_match = msm_serial_ids,
+       .of_to_plat = msm_serial_ofdata_to_platdata,
+       .priv_auto = sizeof(struct msm_serial_data),
+       .probe = msm_serial_probe,
+       .ops = &msm_serial_ops,
+};
+
+#ifdef CONFIG_DEBUG_UART_MSM_GENI
+
+static struct msm_serial_data init_serial_data = {
+       .base = CONFIG_DEBUG_UART_BASE
+};
+
+/* Serial dumb device, to reuse driver code */
+static struct udevice init_dev = {
+       .priv_ = &init_serial_data,
+};
+
+#include <debug_uart.h>
+
+#define CLK_DIV (CONFIG_DEBUG_UART_CLOCK / \
+                                       (CONFIG_BAUDRATE * UART_OVERSAMPLING))
+#if (CONFIG_DEBUG_UART_CLOCK % (CONFIG_BAUDRATE * UART_OVERSAMPLING) > 0)
+#error Clocks cannot be set at early debug. Change CONFIG_BAUDRATE
+#endif
+
+static inline void _debug_uart_init(void)
+{
+       phys_addr_t base = CONFIG_DEBUG_UART_BASE;
+
+       geni_serial_init(&init_dev);
+       geni_serial_baud(base, CLK_DIV, CONFIG_BAUDRATE);
+       qcom_geni_serial_start_tx(base);
+}
+
+static inline void _debug_uart_putc(int ch)
+{
+       phys_addr_t base = CONFIG_DEBUG_UART_BASE;
+
+       writel(DEF_TX_WM, base + SE_GENI_TX_WATERMARK_REG);
+       qcom_geni_serial_setup_tx(base, 1);
+       qcom_geni_serial_poll_bit(&init_dev, SE_GENI_M_IRQ_STATUS,
+                                 M_TX_FIFO_WATERMARK_EN, true);
+
+       writel(ch, base + SE_GENI_TX_FIFOn);
+       writel(M_TX_FIFO_WATERMARK_EN, base + SE_GENI_M_IRQ_CLEAR);
+       qcom_geni_serial_poll_tx_done(&init_dev);
+}
+
+DEBUG_UART_FUNCS
+
+#endif