[U-Boot] [PATCH v3 1/2] serial: Introduce linflex uart support
Eddy Petrișor
eddy.petrisor at gmail.com
Sat May 28 11:56:14 CEST 2016
From: Stoica Cosmin-Stefan <cosminstefan.stoica at freescale.com>
The Linflex module is integrated on some NXP automotive SoCs part of the former
Freescale portfolio, like S32V234, an SoC for Advanced Driver Assistance
Systems.
Original-signed-off-by: Stoica Cosmin-Stefan <cosminstefan.stoica at freescale.com>
Original-signed-off-by: Chircu Bogdan <Bogdan.Chircu at freescale.com>
Original-signed-off-by: Depons Eric <eric.depons at freescale.com>
Original-signed-off-by: Eddy Petrișor <eddy.petrisor at gmail.com>
Signed-off-by: Eddy Petrișor <eddy.petrisor at gmail.com>
---
Notes:
Changes in v2:
Added support for device model. Compatibility with non-DM code is kept
for easier synchronization with the code on the vendor branch where the
conversion to DM is not done for all boards.
Changes in v3:
Removed non-DM compatibility, as requested.
drivers/serial/Makefile | 1 +
drivers/serial/serial_linflexuart.c | 221 ++++++++++++++++++++++++++++++++++++
2 files changed, 222 insertions(+)
create mode 100644 drivers/serial/serial_linflexuart.c
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 9def128..c45cf5d 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_SCIF_CONSOLE) += serial_sh.o
obj-$(CONFIG_ZYNQ_SERIAL) += serial_zynq.o
obj-$(CONFIG_BFIN_SERIAL) += serial_bfin.o
obj-$(CONFIG_FSL_LPUART) += serial_lpuart.o
+obj-$(CONFIG_FSL_LINFLEXUART) += serial_linflexuart.o
obj-$(CONFIG_ARC_SERIAL) += serial_arc.o
obj-$(CONFIG_UNIPHIER_SERIAL) += serial_uniphier.o
obj-$(CONFIG_STM32_SERIAL) += serial_stm32.o
diff --git a/drivers/serial/serial_linflexuart.c b/drivers/serial/serial_linflexuart.c
new file mode 100644
index 0000000..771d0bd
--- /dev/null
+++ b/drivers/serial/serial_linflexuart.c
@@ -0,0 +1,221 @@
+/*
+ * (C) Copyright 2013-2016 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <watchdog.h>
+#include <asm/io.h>
+#include <serial.h>
+#include <linux/compiler.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/clock.h>
+
+#define US1_TDRE (1 << 7)
+#define US1_RDRF (1 << 5)
+#define UC2_TE (1 << 3)
+#define LINCR1_INIT (1 << 0)
+#define LINCR1_MME (1 << 4)
+#define LINCR1_BF (1 << 7)
+#define LINSR_LINS_INITMODE (0x00001000)
+#define LINSR_LINS_MASK (0x0000F000)
+#define UARTCR_UART (1 << 0)
+#define UARTCR_WL0 (1 << 1)
+#define UARTCR_PCE (1 << 2)
+#define UARTCR_PC0 (1 << 3)
+#define UARTCR_TXEN (1 << 4)
+#define UARTCR_RXEN (1 << 5)
+#define UARTCR_PC1 (1 << 6)
+#define UARTSR_DTF (1 << 1)
+#define UARTSR_DRF (1 << 2)
+#define UARTSR_RMB (1 << 9)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifndef CONFIG_DM_SERIAL
+#error "The linflex serial driver does not have non-DM support."
+#endif
+
+static void _linflex_serial_setbrg(struct linflex_fsl *base, int baudrate)
+{
+ u32 clk = mxc_get_clock(MXC_UART_CLK);
+ u32 ibr, fbr;
+
+ if (!baudrate)
+ baudrate = CONFIG_BAUDRATE;
+
+ ibr = (u32) (clk / (16 * gd->baudrate));
+ fbr = (u32) (clk % (16 * gd->baudrate)) * 16;
+
+ __raw_writel(ibr, &base->linibrr);
+ __raw_writel(fbr, &base->linfbrr);
+}
+
+static int _linflex_serial_getc(struct linflex_fsl *base)
+{
+ char c;
+
+ if (!(__raw_readb(&base->uartsr) & UARTSR_DRF))
+ return -EAGAIN;
+
+ if (!(__raw_readl(&base->uartsr) & UARTSR_RMB))
+ return -EAGAIN;
+
+ c = __raw_readl(&base->bdrm);
+ __raw_writeb((__raw_readb(&base->uartsr) | (UARTSR_DRF | UARTSR_RMB)),
+ &base->uartsr);
+ return c;
+}
+
+static int _linflex_serial_putc(struct linflex_fsl *base, const char c)
+{
+ __raw_writeb(c, &base->bdrl);
+
+
+ if (!(__raw_readb(&base->uartsr) & UARTSR_DTF))
+ return -EAGAIN;
+
+ __raw_writeb((__raw_readb(&base->uartsr) | UARTSR_DTF), &base->uartsr);
+
+ return 0;
+}
+
+/*
+ * Initialise the serial port with the given baudrate. The settings
+ * are always 8 data bits, no parity, 1 stop bit, no start bits.
+ */
+static int _linflex_serial_init(struct linflex_fsl *base)
+{
+ volatile u32 ctrl;
+
+ /* set the Linflex in master mode amd activate by-pass filter */
+ ctrl = LINCR1_BF | LINCR1_MME;
+ __raw_writel(ctrl, &base->lincr1);
+
+ /* init mode */
+ ctrl |= LINCR1_INIT;
+ __raw_writel(ctrl, &base->lincr1);
+
+ /* waiting for init mode entry - TODO: add a timeout */
+ while ((__raw_readl(&base->linsr) & LINSR_LINS_MASK) !=
+ LINSR_LINS_INITMODE);
+
+ /* set UART bit to allow writing other bits */
+ __raw_writel(UARTCR_UART, &base->uartcr);
+
+ /* provide data bits, parity, stop bit, etc */
+ serial_setbrg();
+
+ /* 8 bit data, no parity, Tx and Rx enabled, UART mode */
+ __raw_writel(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0
+ | UARTCR_WL0 | UARTCR_UART, &base->uartcr);
+
+ ctrl = __raw_readl(&base->lincr1);
+ ctrl &= ~LINCR1_INIT;
+ __raw_writel(ctrl, &base->lincr1); /* end init mode */
+
+ return 0;
+}
+
+struct linflex_serial_platdata {
+ struct linflex_fsl *base_addr;
+ u8 port_id; /* do we need this? */
+};
+
+struct linflex_serial_priv {
+ struct linflex_fsl *lfuart;
+};
+
+int linflex_serial_setbrg(struct udevice *dev, int baudrate)
+{
+ struct linflex_serial_priv *priv = dev_get_priv(dev);
+
+ _linflex_serial_setbrg(priv->lfuart, baudrate);
+
+ return 0;
+}
+
+static int linflex_serial_getc(struct udevice *dev)
+{
+ struct linflex_serial_priv *priv = dev_get_priv(dev);
+
+ return _linflex_serial_getc(priv->lfuart);
+}
+
+static int linflex_serial_putc(struct udevice *dev, const char ch)
+{
+
+ struct linflex_serial_priv *priv = dev_get_priv(dev);
+
+ return _linflex_serial_putc(priv->lfuart, ch);
+}
+
+static int linflex_serial_pending(struct udevice *dev, bool input)
+{
+ struct linflex_serial_priv *priv = dev_get_priv(dev);
+ uint32_t uartsr = __raw_readl(&priv->lfuart->uartsr);
+
+ if (input)
+ return ((uartsr & UARTSR_DRF) && (uartsr & UARTSR_RMB)) ? 1 : 0;
+ else
+ return uartsr & UARTSR_DTF ? 0 : 1;
+}
+
+static void linflex_serial_init_internal(struct linflex_fsl *lfuart)
+{
+ _linflex_serial_init(lfuart);
+ _linflex_serial_setbrg(lfuart, CONFIG_BAUDRATE);
+ return;
+}
+
+static int linflex_serial_probe(struct udevice *dev)
+{
+ struct linflex_serial_platdata *plat = dev->platdata;
+ struct linflex_serial_priv *priv = dev_get_priv(dev);
+
+ priv->lfuart = (struct linflex_fsl *)plat->base_addr;
+ linflex_serial_init_internal(priv->lfuart);
+
+ return 0;
+}
+
+static const struct dm_serial_ops linflex_serial_ops = {
+ .putc = linflex_serial_putc,
+ .pending = linflex_serial_pending,
+ .getc = linflex_serial_getc,
+ .setbrg = linflex_serial_setbrg,
+};
+
+U_BOOT_DRIVER(serial_linflex) = {
+ .name = "serial_linflex",
+ .id = UCLASS_SERIAL,
+ .probe = linflex_serial_probe,
+ .ops = &linflex_serial_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+ .priv_auto_alloc_size = sizeof(struct linflex_serial_priv),
+};
+
+#ifdef CONFIG_DEBUG_UART_LINFLEXUART
+
+#include <debug_uart.h>
+
+
+static inline void _debUG_uart_init(void)
+{
+ struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;
+
+ linflex_serial_init_internal(base);
+}
+
+static inline void _debug_uart_putc(int ch)
+{
+ struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;
+
+ /* XXX: Is this OK? Should this use the non-DM version? */
+ _linflex_serial_putc(base, ch);
+}
+
+#endif /* CONFIG_DEBUG_UART_LINFLEXUART */
--
2.5.0
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