[PATCH v2 5/6] tty: serial: Add linflexuart driver for S32V234
From: Stefan-gabriel Mirea
Date: Fri Aug 09 2019 - 07:29:31 EST
Introduce support for LINFlex driver, based on:
- the version of Freescale LPUART driver after commit b3e3bf2ef2c7 ("Merge
4.0-rc7 into tty-next");
- commit abf1e0a98083 ("tty: serial: fsl_lpuart: lock port on console
write").
In this basic version, the driver can be tested using initramfs and relies
on the clocks and pin muxing set up by U-Boot.
Remarks concerning the earlycon support:
- LinFlexD does not allow character transmissions in the INIT mode (see
section 47.4.2.1 in the reference manual[1]). Therefore, a mutual
exclusion between the first linflex_setup_watermark/linflex_set_termios
executions and linflex_earlycon_putchar was employed and the characters
normally sent to earlycon during initialization are kept in a buffer and
sent afterwards.
- Empirically, character transmission is also forbidden within the last 1-2
ms before entering the INIT mode, so we use an explicit timeout
(PREINIT_DELAY) between linflex_earlycon_putchar and the first call to
linflex_setup_watermark.
- U-Boot currently uses the UART FIFO mode, while this driver makes the
transition to the buffer mode. Therefore, the earlycon putchar function
matches the U-Boot behavior before initializations and the Linux behavior
after.
[1] https://www.nxp.com/webapp/Download?colCode=S32V234RM
Signed-off-by: Stoica Cosmin-Stefan <cosmin.stoica@xxxxxxx>
Signed-off-by: Adrian.Nitu <adrian.nitu@xxxxxxxxxxxxx>
Signed-off-by: Larisa Grigore <Larisa.Grigore@xxxxxxx>
Signed-off-by: Ana Nedelcu <B56683@xxxxxxxxxxxxx>
Signed-off-by: Mihaela Martinas <Mihaela.Martinas@xxxxxxxxxxxxx>
Signed-off-by: Matthew Nunez <matthew.nunez@xxxxxxx>
[stefan-gabriel.mirea@xxxxxxx: Reduced for upstreaming and implemented
earlycon support]
Signed-off-by: Stefan-Gabriel Mirea <stefan-gabriel.mirea@xxxxxxx>
---
.../admin-guide/kernel-parameters.txt | 6 +
drivers/tty/serial/Kconfig | 15 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/fsl_linflexuart.c | 942 ++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
5 files changed, 967 insertions(+)
create mode 100644 drivers/tty/serial/fsl_linflexuart.c
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 46b826fcb5ad..4d545732aadc 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1090,6 +1090,12 @@
the framebuffer, pass the 'ram' option so that it is
mapped with the correct attributes.
+ linflex,<addr>
+ Use early console provided by Freescale LinFlex UART
+ serial driver for NXP S32V234 SoCs. A valid base
+ address must be provided, and the serial port must
+ already be setup and configured.
+
earlyprintk= [X86,SH,ARM,M68k,S390]
earlyprintk=vga
earlyprintk=sclp
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index fd385c8c53a5..b4fa2f7c96bd 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1452,6 +1452,21 @@ config SERIAL_FSL_LPUART_CONSOLE
If you have enabled the lpuart serial port on the Freescale SoCs,
you can make it the console by answering Y to this option.
+config SERIAL_FSL_LINFLEXUART
+ tristate "Freescale linflexuart serial port support"
+ select SERIAL_CORE
+ help
+ Support for the on-chip linflexuart on some Freescale SOCs.
+
+config SERIAL_FSL_LINFLEXUART_CONSOLE
+ bool "Console on Freescale linflexuart serial port"
+ depends on SERIAL_FSL_LINFLEXUART=y
+ select SERIAL_CORE_CONSOLE
+ select SERIAL_EARLYCON
+ help
+ If you have enabled the linflexuart serial port on the Freescale
+ SoCs, you can make it the console by answering Y to this option.
+
config SERIAL_CONEXANT_DIGICOLOR
tristate "Conexant Digicolor CX92xxx USART serial port support"
depends on OF
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index 7cd7cabfa6c4..7a3d52a453b7 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
obj-$(CONFIG_SERIAL_RP2) += rp2.o
obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
+obj-$(CONFIG_SERIAL_FSL_LINFLEXUART) += fsl_linflexuart.o
obj-$(CONFIG_SERIAL_CONEXANT_DIGICOLOR) += digicolor-usart.o
obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
new file mode 100644
index 000000000000..26b9601a0952
--- /dev/null
+++ b/drivers/tty/serial/fsl_linflexuart.c
@@ -0,0 +1,942 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Freescale linflexuart serial port driver
+ *
+ * Copyright 2012-2016 Freescale Semiconductor, Inc.
+ * Copyright 2017-2018 NXP
+ */
+
+#if defined(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE) && \
+ defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/console.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+
+/* All registers are 32-bit width */
+
+#define LINCR1 0x0000 /* LIN control register */
+#define LINIER 0x0004 /* LIN interrupt enable register */
+#define LINSR 0x0008 /* LIN status register */
+#define LINESR 0x000C /* LIN error status register */
+#define UARTCR 0x0010 /* UART mode control register */
+#define UARTSR 0x0014 /* UART mode status register */
+#define LINTCSR 0x0018 /* LIN timeout control status register */
+#define LINOCR 0x001C /* LIN output compare register */
+#define LINTOCR 0x0020 /* LIN timeout control register */
+#define LINFBRR 0x0024 /* LIN fractional baud rate register */
+#define LINIBRR 0x0028 /* LIN integer baud rate register */
+#define LINCFR 0x002C /* LIN checksum field register */
+#define LINCR2 0x0030 /* LIN control register 2 */
+#define BIDR 0x0034 /* Buffer identifier register */
+#define BDRL 0x0038 /* Buffer data register least significant */
+#define BDRM 0x003C /* Buffer data register most significant */
+#define IFER 0x0040 /* Identifier filter enable register */
+#define IFMI 0x0044 /* Identifier filter match index */
+#define IFMR 0x0048 /* Identifier filter mode register */
+#define GCR 0x004C /* Global control register */
+#define UARTPTO 0x0050 /* UART preset timeout register */
+#define UARTCTO 0x0054 /* UART current timeout register */
+
+/*
+ * Register field definitions
+ */
+
+#define LINFLEXD_LINCR1_INIT BIT(0)
+#define LINFLEXD_LINCR1_MME BIT(4)
+#define LINFLEXD_LINCR1_BF BIT(7)
+
+#define LINFLEXD_LINSR_LINS_INITMODE BIT(12)
+#define LINFLEXD_LINSR_LINS_MASK (0xF << 12)
+
+#define LINFLEXD_LINIER_SZIE BIT(15)
+#define LINFLEXD_LINIER_OCIE BIT(14)
+#define LINFLEXD_LINIER_BEIE BIT(13)
+#define LINFLEXD_LINIER_CEIE BIT(12)
+#define LINFLEXD_LINIER_HEIE BIT(11)
+#define LINFLEXD_LINIER_FEIE BIT(8)
+#define LINFLEXD_LINIER_BOIE BIT(7)
+#define LINFLEXD_LINIER_LSIE BIT(6)
+#define LINFLEXD_LINIER_WUIE BIT(5)
+#define LINFLEXD_LINIER_DBFIE BIT(4)
+#define LINFLEXD_LINIER_DBEIETOIE BIT(3)
+#define LINFLEXD_LINIER_DRIE BIT(2)
+#define LINFLEXD_LINIER_DTIE BIT(1)
+#define LINFLEXD_LINIER_HRIE BIT(0)
+
+#define LINFLEXD_UARTCR_OSR_MASK (0xF << 24)
+#define LINFLEXD_UARTCR_OSR(uartcr) (((uartcr) \
+ & LINFLEXD_UARTCR_OSR_MASK) >> 24)
+
+#define LINFLEXD_UARTCR_ROSE BIT(23)
+
+#define LINFLEXD_UARTCR_RFBM BIT(9)
+#define LINFLEXD_UARTCR_TFBM BIT(8)
+#define LINFLEXD_UARTCR_WL1 BIT(7)
+#define LINFLEXD_UARTCR_PC1 BIT(6)
+
+#define LINFLEXD_UARTCR_RXEN BIT(5)
+#define LINFLEXD_UARTCR_TXEN BIT(4)
+#define LINFLEXD_UARTCR_PC0 BIT(3)
+
+#define LINFLEXD_UARTCR_PCE BIT(2)
+#define LINFLEXD_UARTCR_WL0 BIT(1)
+#define LINFLEXD_UARTCR_UART BIT(0)
+
+#define LINFLEXD_UARTSR_SZF BIT(15)
+#define LINFLEXD_UARTSR_OCF BIT(14)
+#define LINFLEXD_UARTSR_PE3 BIT(13)
+#define LINFLEXD_UARTSR_PE2 BIT(12)
+#define LINFLEXD_UARTSR_PE1 BIT(11)
+#define LINFLEXD_UARTSR_PE0 BIT(10)
+#define LINFLEXD_UARTSR_RMB BIT(9)
+#define LINFLEXD_UARTSR_FEF BIT(8)
+#define LINFLEXD_UARTSR_BOF BIT(7)
+#define LINFLEXD_UARTSR_RPS BIT(6)
+#define LINFLEXD_UARTSR_WUF BIT(5)
+#define LINFLEXD_UARTSR_4 BIT(4)
+
+#define LINFLEXD_UARTSR_TO BIT(3)
+
+#define LINFLEXD_UARTSR_DRFRFE BIT(2)
+#define LINFLEXD_UARTSR_DTFTFF BIT(1)
+#define LINFLEXD_UARTSR_NF BIT(0)
+#define LINFLEXD_UARTSR_PE (LINFLEXD_UARTSR_PE0 |\
+ LINFLEXD_UARTSR_PE1 |\
+ LINFLEXD_UARTSR_PE2 |\
+ LINFLEXD_UARTSR_PE3)
+
+#define LINFLEX_LDIV_MULTIPLIER (16)
+
+#define DRIVER_NAME "fsl-linflexuart"
+#define DEV_NAME "ttyLF"
+#define UART_NR 4
+
+#define EARLYCON_BUFFER_INITIAL_CAP 8
+
+#define PREINIT_DELAY 2000 /* us */
+
+static const struct of_device_id linflex_dt_ids[] = {
+ {
+ .compatible = "fsl,s32-linflexuart",
+ },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, linflex_dt_ids);
+
+#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
+static struct uart_port *earlycon_port;
+static bool linflex_earlycon_same_instance;
+static spinlock_t init_lock;
+static bool during_init;
+
+static struct {
+ char *content;
+ unsigned int len, cap;
+} earlycon_buf;
+#endif
+
+static void linflex_stop_tx(struct uart_port *port)
+{
+ unsigned long ier;
+
+ ier = readl(port->membase + LINIER);
+ ier &= ~(LINFLEXD_LINIER_DTIE);
+ writel(ier, port->membase + LINIER);
+}
+
+static void linflex_stop_rx(struct uart_port *port)
+{
+ unsigned long ier;
+
+ ier = readl(port->membase + LINIER);
+ writel(ier & ~LINFLEXD_LINIER_DRIE, port->membase + LINIER);
+}
+
+static inline void linflex_transmit_buffer(struct uart_port *sport)
+{
+ struct circ_buf *xmit = &sport->state->xmit;
+ unsigned char c;
+ unsigned long status;
+
+ while (!uart_circ_empty(xmit)) {
+ c = xmit->buf[xmit->tail];
+ writeb(c, sport->membase + BDRL);
+
+ /* Waiting for data transmission completed. */
+ while (((status = readl(sport->membase + UARTSR)) &
+ LINFLEXD_UARTSR_DTFTFF) !=
+ LINFLEXD_UARTSR_DTFTFF)
+ ;
+
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ sport->icount.tx++;
+
+ writel(status | LINFLEXD_UARTSR_DTFTFF,
+ sport->membase + UARTSR);
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(sport);
+
+ if (uart_circ_empty(xmit))
+ linflex_stop_tx(sport);
+}
+
+static void linflex_start_tx(struct uart_port *port)
+{
+ unsigned long ier;
+
+ linflex_transmit_buffer(port);
+ ier = readl(port->membase + LINIER);
+ writel(ier | LINFLEXD_LINIER_DTIE, port->membase + LINIER);
+}
+
+static irqreturn_t linflex_txint(int irq, void *dev_id)
+{
+ struct uart_port *sport = dev_id;
+ struct circ_buf *xmit = &sport->state->xmit;
+ unsigned long flags;
+ unsigned long status;
+
+ spin_lock_irqsave(&sport->lock, flags);
+
+ if (sport->x_char) {
+ writeb(sport->x_char, sport->membase + BDRL);
+
+ /* waiting for data transmission completed */
+ while (((status = readl(sport->membase + UARTSR)) &
+ LINFLEXD_UARTSR_DTFTFF) != LINFLEXD_UARTSR_DTFTFF)
+ ;
+
+ writel(status | LINFLEXD_UARTSR_DTFTFF,
+ sport->membase + UARTSR);
+
+ goto out;
+ }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(sport)) {
+ linflex_stop_tx(sport);
+ goto out;
+ }
+
+ linflex_transmit_buffer(sport);
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(sport);
+
+out:
+ spin_unlock_irqrestore(&sport->lock, flags);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t linflex_rxint(int irq, void *dev_id)
+{
+ struct uart_port *sport = dev_id;
+ unsigned int flg;
+ struct tty_port *port = &sport->state->port;
+ unsigned long flags, status;
+ unsigned char rx;
+
+ spin_lock_irqsave(&sport->lock, flags);
+
+ status = readl(sport->membase + UARTSR);
+ while (status & LINFLEXD_UARTSR_RMB) {
+ rx = readb(sport->membase + BDRM);
+ flg = TTY_NORMAL;
+ sport->icount.rx++;
+
+ if (status & (LINFLEXD_UARTSR_BOF | LINFLEXD_UARTSR_SZF |
+ LINFLEXD_UARTSR_FEF | LINFLEXD_UARTSR_PE)) {
+ if (status & LINFLEXD_UARTSR_SZF)
+ status |= LINFLEXD_UARTSR_SZF;
+ if (status & LINFLEXD_UARTSR_BOF)
+ status |= LINFLEXD_UARTSR_BOF;
+ if (status & LINFLEXD_UARTSR_FEF)
+ status |= LINFLEXD_UARTSR_FEF;
+ if (status & LINFLEXD_UARTSR_PE)
+ status |= LINFLEXD_UARTSR_PE;
+ }
+
+ writel(status | LINFLEXD_UARTSR_RMB | LINFLEXD_UARTSR_DRFRFE,
+ sport->membase + UARTSR);
+ status = readl(sport->membase + UARTSR);
+
+ if (uart_handle_sysrq_char(sport, (unsigned char)rx))
+ continue;
+
+#ifdef SUPPORT_SYSRQ
+ sport->sysrq = 0;
+#endif
+ tty_insert_flip_char(port, rx, flg);
+ }
+
+ spin_unlock_irqrestore(&sport->lock, flags);
+
+ tty_flip_buffer_push(port);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t linflex_int(int irq, void *dev_id)
+{
+ struct uart_port *sport = dev_id;
+ unsigned long status;
+
+ status = readl(sport->membase + UARTSR);
+
+ if (status & LINFLEXD_UARTSR_DRFRFE)
+ linflex_rxint(irq, dev_id);
+ if (status & LINFLEXD_UARTSR_DTFTFF)
+ linflex_txint(irq, dev_id);
+
+ return IRQ_HANDLED;
+}
+
+/* return TIOCSER_TEMT when transmitter is not busy */
+static unsigned int linflex_tx_empty(struct uart_port *port)
+{
+ unsigned long status;
+
+ status = readl(port->membase + UARTSR) & LINFLEXD_UARTSR_DTFTFF;
+
+ return status ? TIOCSER_TEMT : 0;
+}
+
+static unsigned int linflex_get_mctrl(struct uart_port *port)
+{
+ return 0;
+}
+
+static void linflex_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void linflex_break_ctl(struct uart_port *port, int break_state)
+{
+}
+
+static void linflex_setup_watermark(struct uart_port *sport)
+{
+ unsigned long cr, ier, cr1;
+
+ /* Disable transmission/reception */
+ ier = readl(sport->membase + LINIER);
+ ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
+ writel(ier, sport->membase + LINIER);
+
+ cr = readl(sport->membase + UARTCR);
+ cr &= ~(LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN);
+ writel(cr, sport->membase + UARTCR);
+
+ /* Enter initialization mode by setting INIT bit */
+
+ /* set the Linflex in master mode and activate by-pass filter */
+ cr1 = LINFLEXD_LINCR1_BF | LINFLEXD_LINCR1_MME
+ | LINFLEXD_LINCR1_INIT;
+ writel(cr1, sport->membase + LINCR1);
+
+ /* wait for init mode entry */
+ while ((readl(sport->membase + LINSR)
+ & LINFLEXD_LINSR_LINS_MASK)
+ != LINFLEXD_LINSR_LINS_INITMODE)
+ ;
+
+ /*
+ * UART = 0x1; - Linflex working in UART mode
+ * TXEN = 0x1; - Enable transmission of data now
+ * RXEn = 0x1; - Receiver enabled
+ * WL0 = 0x1; - 8 bit data
+ * PCE = 0x0; - No parity
+ */
+
+ /* set UART bit to allow writing other bits */
+ writel(LINFLEXD_UARTCR_UART, sport->membase + UARTCR);
+
+ cr = (LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN |
+ LINFLEXD_UARTCR_WL0 | LINFLEXD_UARTCR_UART);
+
+ writel(cr, sport->membase + UARTCR);
+
+ cr1 &= ~(LINFLEXD_LINCR1_INIT);
+
+ writel(cr1, sport->membase + LINCR1);
+
+ ier = readl(sport->membase + LINIER);
+ ier |= LINFLEXD_LINIER_DRIE;
+ ier |= LINFLEXD_LINIER_DTIE;
+
+ writel(ier, sport->membase + LINIER);
+}
+
+static int linflex_startup(struct uart_port *port)
+{
+ int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ linflex_setup_watermark(port);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ ret = devm_request_irq(port->dev, port->irq, linflex_int, 0,
+ DRIVER_NAME, port);
+
+ return ret;
+}
+
+static void linflex_shutdown(struct uart_port *port)
+{
+ unsigned long ier;
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* disable interrupts */
+ ier = readl(port->membase + LINIER);
+ ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
+ writel(ier, port->membase + LINIER);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ devm_free_irq(port->dev, port->irq, port);
+}
+
+static void
+linflex_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
+{
+ unsigned long flags;
+ unsigned long cr, old_cr, cr1;
+ unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+
+ cr = readl(port->membase + UARTCR);
+ old_cr = cr;
+
+ /* Enter initialization mode by setting INIT bit */
+ cr1 = readl(port->membase + LINCR1);
+ cr1 |= LINFLEXD_LINCR1_INIT;
+ writel(cr1, port->membase + LINCR1);
+
+ /* wait for init mode entry */
+ while ((readl(port->membase + LINSR)
+ & LINFLEXD_LINSR_LINS_MASK)
+ != LINFLEXD_LINSR_LINS_INITMODE)
+ ;
+
+ /*
+ * only support CS8 and CS7, and for CS7 must enable PE.
+ * supported mode:
+ * - (7,e/o,1)
+ * - (8,n,1)
+ * - (8,e/o,1)
+ */
+ /* enter the UART into configuration mode */
+
+ while ((termios->c_cflag & CSIZE) != CS8 &&
+ (termios->c_cflag & CSIZE) != CS7) {
+ termios->c_cflag &= ~CSIZE;
+ termios->c_cflag |= old_csize;
+ old_csize = CS8;
+ }
+
+ if ((termios->c_cflag & CSIZE) == CS7) {
+ /* Word length: WL1WL0:00 */
+ cr = old_cr & ~LINFLEXD_UARTCR_WL1 & ~LINFLEXD_UARTCR_WL0;
+ }
+
+ if ((termios->c_cflag & CSIZE) == CS8) {
+ /* Word length: WL1WL0:01 */
+ cr = (old_cr | LINFLEXD_UARTCR_WL0) & ~LINFLEXD_UARTCR_WL1;
+ }
+
+ if (termios->c_cflag & CMSPAR) {
+ if ((termios->c_cflag & CSIZE) != CS8) {
+ termios->c_cflag &= ~CSIZE;
+ termios->c_cflag |= CS8;
+ }
+ /* has a space/sticky bit */
+ cr |= LINFLEXD_UARTCR_WL0;
+ }
+
+ if (termios->c_cflag & CSTOPB)
+ termios->c_cflag &= ~CSTOPB;
+
+ /* parity must be enabled when CS7 to match 8-bits format */
+ if ((termios->c_cflag & CSIZE) == CS7)
+ termios->c_cflag |= PARENB;
+
+ if ((termios->c_cflag & PARENB)) {
+ cr |= LINFLEXD_UARTCR_PCE;
+ if (termios->c_cflag & PARODD)
+ cr = (cr | LINFLEXD_UARTCR_PC0) &
+ (~LINFLEXD_UARTCR_PC1);
+ else
+ cr = cr & (~LINFLEXD_UARTCR_PC1 &
+ ~LINFLEXD_UARTCR_PC0);
+ } else {
+ cr &= ~LINFLEXD_UARTCR_PCE;
+ }
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ port->read_status_mask = 0;
+
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= (LINFLEXD_UARTSR_FEF |
+ LINFLEXD_UARTSR_PE0 |
+ LINFLEXD_UARTSR_PE1 |
+ LINFLEXD_UARTSR_PE2 |
+ LINFLEXD_UARTSR_PE3);
+ if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+ port->read_status_mask |= LINFLEXD_UARTSR_FEF;
+
+ /* characters to ignore */
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
+ if (termios->c_iflag & IGNBRK) {
+ port->ignore_status_mask |= LINFLEXD_UARTSR_PE;
+ /*
+ * if we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= LINFLEXD_UARTSR_BOF;
+ }
+
+ writel(cr, port->membase + UARTCR);
+
+ cr1 &= ~(LINFLEXD_LINCR1_INIT);
+
+ writel(cr1, port->membase + LINCR1);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *linflex_type(struct uart_port *port)
+{
+ return "FSL_LINFLEX";
+}
+
+static void linflex_release_port(struct uart_port *port)
+{
+ /* nothing to do */
+}
+
+static int linflex_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+/* configure/auto-configure the port */
+static void linflex_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_LINFLEXUART;
+}
+
+static const struct uart_ops linflex_pops = {
+ .tx_empty = linflex_tx_empty,
+ .set_mctrl = linflex_set_mctrl,
+ .get_mctrl = linflex_get_mctrl,
+ .stop_tx = linflex_stop_tx,
+ .start_tx = linflex_start_tx,
+ .stop_rx = linflex_stop_rx,
+ .break_ctl = linflex_break_ctl,
+ .startup = linflex_startup,
+ .shutdown = linflex_shutdown,
+ .set_termios = linflex_set_termios,
+ .type = linflex_type,
+ .request_port = linflex_request_port,
+ .release_port = linflex_release_port,
+ .config_port = linflex_config_port,
+};
+
+static struct uart_port *linflex_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
+static void linflex_console_putchar(struct uart_port *port, int ch)
+{
+ unsigned long cr;
+
+ cr = readl(port->membase + UARTCR);
+
+ writeb(ch, port->membase + BDRL);
+
+ if (!(cr & LINFLEXD_UARTCR_TFBM))
+ while ((readl(port->membase + UARTSR) &
+ LINFLEXD_UARTSR_DTFTFF)
+ != LINFLEXD_UARTSR_DTFTFF)
+ ;
+ else
+ while (readl(port->membase + UARTSR) &
+ LINFLEXD_UARTSR_DTFTFF)
+ ;
+
+ if (!(cr & LINFLEXD_UARTCR_TFBM)) {
+ writel((readl(port->membase + UARTSR) |
+ LINFLEXD_UARTSR_DTFTFF),
+ port->membase + UARTSR);
+ }
+}
+
+static void linflex_earlycon_putchar(struct uart_port *port, int ch)
+{
+ unsigned long flags;
+ char *ret;
+
+ if (!linflex_earlycon_same_instance) {
+ linflex_console_putchar(port, ch);
+ return;
+ }
+
+ spin_lock_irqsave(&init_lock, flags);
+ if (!during_init)
+ goto outside_init;
+
+ if (earlycon_buf.len >= 1 << CONFIG_LOG_BUF_SHIFT)
+ goto init_release;
+
+ if (!earlycon_buf.cap) {
+ earlycon_buf.content = kmalloc(EARLYCON_BUFFER_INITIAL_CAP,
+ GFP_ATOMIC);
+ earlycon_buf.cap = earlycon_buf.content ?
+ EARLYCON_BUFFER_INITIAL_CAP : 0;
+ } else if (earlycon_buf.len == earlycon_buf.cap) {
+ ret = krealloc(earlycon_buf.content, earlycon_buf.cap << 1,
+ GFP_ATOMIC);
+ if (ret) {
+ earlycon_buf.content = ret;
+ earlycon_buf.cap <<= 1;
+ }
+ }
+
+ if (earlycon_buf.len < earlycon_buf.cap)
+ earlycon_buf.content[earlycon_buf.len++] = ch;
+
+ goto init_release;
+
+outside_init:
+ linflex_console_putchar(port, ch);
+init_release:
+ spin_unlock_irqrestore(&init_lock, flags);
+}
+
+static void linflex_string_write(struct uart_port *sport, const char *s,
+ unsigned int count)
+{
+ unsigned long cr, ier = 0;
+
+ ier = readl(sport->membase + LINIER);
+ linflex_stop_tx(sport);
+
+ cr = readl(sport->membase + UARTCR);
+ cr |= (LINFLEXD_UARTCR_TXEN);
+ writel(cr, sport->membase + UARTCR);
+
+ uart_console_write(sport, s, count, linflex_console_putchar);
+
+ writel(ier, sport->membase + LINIER);
+}
+
+static void
+linflex_console_write(struct console *co, const char *s, unsigned int count)
+{
+ struct uart_port *sport = linflex_ports[co->index];
+ unsigned long flags;
+ int locked = 1;
+
+ if (sport->sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+ locked = spin_trylock_irqsave(&sport->lock, flags);
+ else
+ spin_lock_irqsave(&sport->lock, flags);
+
+ linflex_string_write(sport, s, count);
+
+ if (locked)
+ spin_unlock_irqrestore(&sport->lock, flags);
+}
+
+/*
+ * if the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+linflex_console_get_options(struct uart_port *sport, int *parity, int *bits)
+{
+ unsigned long cr;
+
+ cr = readl(sport->membase + UARTCR);
+ cr &= LINFLEXD_UARTCR_RXEN | LINFLEXD_UARTCR_TXEN;
+
+ if (!cr)
+ return;
+
+ /* ok, the port was enabled */
+
+ *parity = 'n';
+ if (cr & LINFLEXD_UARTCR_PCE) {
+ if (cr & LINFLEXD_UARTCR_PC0)
+ *parity = 'o';
+ else
+ *parity = 'e';
+ }
+
+ if ((cr & LINFLEXD_UARTCR_WL0) && ((cr & LINFLEXD_UARTCR_WL1) == 0)) {
+ if (cr & LINFLEXD_UARTCR_PCE)
+ *bits = 9;
+ else
+ *bits = 8;
+ }
+}
+
+static int __init linflex_console_setup(struct console *co, char *options)
+{
+ struct uart_port *sport;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+ int ret;
+ int i;
+ unsigned long flags;
+ /*
+ * check whether an invalid uart number has been specified, and
+ * if so, search for the first available port that does have
+ * console support.
+ */
+ if (co->index == -1 || co->index >= ARRAY_SIZE(linflex_ports))
+ co->index = 0;
+
+ sport = linflex_ports[co->index];
+ if (!sport)
+ return -ENODEV;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ else
+ linflex_console_get_options(sport, &parity, &bits);
+
+ if (earlycon_port && sport->mapbase == earlycon_port->mapbase) {
+ linflex_earlycon_same_instance = true;
+
+ spin_lock_irqsave(&init_lock, flags);
+ during_init = true;
+ spin_unlock_irqrestore(&init_lock, flags);
+
+ /* Workaround for character loss or output of many invalid
+ * characters, when INIT mode is entered shortly after a
+ * character has just been printed.
+ */
+ udelay(PREINIT_DELAY);
+ }
+
+ linflex_setup_watermark(sport);
+
+ ret = uart_set_options(sport, co, baud, parity, bits, flow);
+
+ if (!linflex_earlycon_same_instance)
+ goto done;
+
+ spin_lock_irqsave(&init_lock, flags);
+
+ /* Emptying buffer */
+ if (earlycon_buf.len) {
+ for (i = 0; i < earlycon_buf.len; i++)
+ linflex_console_putchar(earlycon_port,
+ earlycon_buf.content[i]);
+
+ kfree(earlycon_buf.content);
+ earlycon_buf.len = 0;
+ }
+
+ during_init = false;
+ spin_unlock_irqrestore(&init_lock, flags);
+
+done:
+ return ret;
+}
+
+static struct uart_driver linflex_reg;
+static struct console linflex_console = {
+ .name = DEV_NAME,
+ .write = linflex_console_write,
+ .device = uart_console_device,
+ .setup = linflex_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &linflex_reg,
+};
+
+static void linflex_earlycon_write(struct console *con, const char *s,
+ unsigned int n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, linflex_earlycon_putchar);
+}
+
+static int __init linflex_early_console_setup(struct earlycon_device *device,
+ const char *options)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = linflex_earlycon_write;
+ earlycon_port = &device->port;
+
+ return 0;
+}
+
+OF_EARLYCON_DECLARE(linflex, "fsl,s32-linflexuart",
+ linflex_early_console_setup);
+
+#define LINFLEX_CONSOLE (&linflex_console)
+#else
+#define LINFLEX_CONSOLE NULL
+#endif
+
+static struct uart_driver linflex_reg = {
+ .owner = THIS_MODULE,
+ .driver_name = DRIVER_NAME,
+ .dev_name = DEV_NAME,
+ .nr = ARRAY_SIZE(linflex_ports),
+ .cons = LINFLEX_CONSOLE,
+};
+
+static int linflex_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct uart_port *sport;
+ struct resource *res;
+ int ret;
+
+ sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+ if (!sport)
+ return -ENOMEM;
+
+ ret = of_alias_get_id(np, "serial");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+ return ret;
+ }
+ if (ret >= UART_NR) {
+ dev_err(&pdev->dev, "driver limited to %d serial ports\n",
+ UART_NR);
+ return -ENOMEM;
+ }
+
+ sport->line = ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ sport->mapbase = res->start;
+ sport->membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(sport->membase))
+ return PTR_ERR(sport->membase);
+
+ sport->dev = &pdev->dev;
+ sport->type = PORT_LINFLEXUART;
+ sport->iotype = UPIO_MEM;
+ sport->irq = platform_get_irq(pdev, 0);
+ sport->ops = &linflex_pops;
+ sport->flags = UPF_BOOT_AUTOCONF;
+
+ linflex_ports[sport->line] = sport;
+
+ platform_set_drvdata(pdev, sport);
+
+ ret = uart_add_one_port(&linflex_reg, sport);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int linflex_remove(struct platform_device *pdev)
+{
+ struct uart_port *sport = platform_get_drvdata(pdev);
+
+ uart_remove_one_port(&linflex_reg, sport);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int linflex_suspend(struct device *dev)
+{
+ struct uart_port *sport = dev_get_drvdata(dev);
+
+ uart_suspend_port(&linflex_reg, sport);
+
+ return 0;
+}
+
+static int linflex_resume(struct device *dev)
+{
+ struct uart_port *sport = dev_get_drvdata(dev);
+
+ uart_resume_port(&linflex_reg, sport);
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(linflex_pm_ops, linflex_suspend, linflex_resume);
+
+static struct platform_driver linflex_driver = {
+ .probe = linflex_probe,
+ .remove = linflex_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = linflex_dt_ids,
+ .pm = &linflex_pm_ops,
+ },
+};
+
+static int __init linflex_serial_init(void)
+{
+ int ret;
+
+ ret = uart_register_driver(&linflex_reg);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&linflex_driver);
+ if (ret)
+ uart_unregister_driver(&linflex_reg);
+
+#ifdef CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE
+ spin_lock_init(&init_lock);
+#endif
+
+ return ret;
+}
+
+static void __exit linflex_serial_exit(void)
+{
+ platform_driver_unregister(&linflex_driver);
+ uart_unregister_driver(&linflex_reg);
+}
+
+module_init(linflex_serial_init);
+module_exit(linflex_serial_exit);
+
+MODULE_DESCRIPTION("Freescale linflex serial port driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 5642c05e0da0..25a3dead4473 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -293,4 +293,7 @@
/* SiFive UART */
#define PORT_SIFIVE_V0 120
+/* Freescale Linflex UART */
+#define PORT_LINFLEXUART 121
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
2.22.0