[U-Boot] [PATCH v5 04/14] serial: add serial driver for BCM6345

Daniel Schwierzeck
2017-04-23T20:12:04Z

Am 23.04.2017 um 10:43 schrieb Álvaro Fernández Rojas:
> It is based on linux/drivers/tty/serial/bcm63xx_uart.c
>
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---
> v5: No changes.
> v4: Add more missing register configurations based on CFE.
> v3: Several improvements:
> - Add missing register configurations based on CFE.
> - Replace tabs with whitespaces.
> - Cosmetic fixes.
> v2: Introduce changes suggested by Daniel Schwierzeck:
> - Remove unneeded defines.
> - Fix incorrect multi-line comment.
>
> drivers/serial/Kconfig | 14 ++
> drivers/serial/Makefile | 1 +
> drivers/serial/serial_bcm6345.c | 311 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 326 insertions(+)
> create mode 100644 drivers/serial/serial_bcm6345.c
>
> diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
> index c0ec2ec..ca776d8 100644
> --- a/drivers/serial/Kconfig
> +++ b/drivers/serial/Kconfig
> @@ -134,6 +134,14 @@ config DEBUG_UART_ATMEL
> 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_BCM6345
> + bool "BCM6345 UART"
> + depends on BCM6345_SERIAL
> + help
> + Select this to enable a debug UART on BCM6345 SoCs. 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_NS16550
> bool "ns16550"
> help
> @@ -339,6 +347,12 @@ config ATMEL_USART
> configured in the device tree, and input clock frequency can
> be got from the clk node.
>
> +config BCM6345_SERIAL
> + bool "Support for BCM6345 UART"
> + depends on DM_SERIAL

depends on DM_SERIAL && ARCH_BMIPS

> + help
> + Select this to enable UART on BCM6345 SoCs.
> +
> config FSL_LPUART
> bool "Freescale LPUART support"
> help
> diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
> index 4382cf9..dca31b2 100644
> --- a/drivers/serial/Makefile
> +++ b/drivers/serial/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_ALTERA_JTAG_UART) += altera_jtag_uart.o
> obj-$(CONFIG_AR933X_UART) += serial_ar933x.o
> obj-$(CONFIG_ARM_DCC) += arm_dcc.o
> obj-$(CONFIG_ATMEL_USART) += atmel_usart.o
> +obj-$(CONFIG_BCM6345_SERIAL) += serial_bcm6345.o
> obj-$(CONFIG_EFI_APP) += serial_efi.o
> obj-$(CONFIG_LPC32XX_HSUART) += lpc32xx_hsuart.o
> obj-$(CONFIG_MCFUART) += mcfuart.o
> diff --git a/drivers/serial/serial_bcm6345.c b/drivers/serial/serial_bcm6345.c
> new file mode 100644
> index 0000000..e4d3497
> --- /dev/null
> +++ b/drivers/serial/serial_bcm6345.c
> @@ -0,0 +1,311 @@
> +/*
> + * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
> + *
> + * Derived from linux/drivers/tty/serial/bcm63xx_uart.c:
> + * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <clk.h>
> +#include <debug_uart.h>
> +#include <errno.h>
> +#include <serial.h>
> +#include <asm/io.h>
> +#include <asm/types.h>
> +#include <dm/device.h>
> +
> +/* UART Control register */
> +#define UART_CTL_REG 0x0
> +#define UART_CTL_RXTIMEOUT_MASK 0x1f
> +#define UART_CTL_RSTRXFIFO_SHIFT 6
> +#define UART_CTL_RSTRXFIFO_MASK (1 << UART_CTL_RSTRXFIFO_SHIFT)
> +#define UART_CTL_RSTTXFIFO_SHIFT 7
> +#define UART_CTL_RSTTXFIFO_MASK (1 << UART_CTL_RSTTXFIFO_SHIFT)
> +#define UART_CTL_STOPBITS_SHIFT 8
> +#define UART_CTL_STOPBITS_MASK (0xf << UART_CTL_STOPBITS_SHIFT)
> +#define UART_CTL_STOPBITS_1 (0x7 << UART_CTL_STOPBITS_SHIFT)
> +#define UART_CTL_BITSPERSYM_SHIFT 12
> +#define UART_CTL_BITSPERSYM_MASK (0x3 << UART_CTL_BITSPERSYM_SHIFT)
> +#define UART_CTL_XMITBRK_SHIFT 14
> +#define UART_CTL_XMITBRK_MASK (1 << UART_CTL_XMITBRK_SHIFT)
> +#define UART_CTL_RSVD_SHIFT 15
> +#define UART_CTL_RSVD_MASK (1 << UART_CTL_RSVD_SHIFT)
> +#define UART_CTL_RXPAREVEN_SHIFT 16
> +#define UART_CTL_RXPAREVEN_MASK (1 << UART_CTL_RXPAREVEN_SHIFT)
> +#define UART_CTL_RXPAREN_SHIFT 17
> +#define UART_CTL_RXPAREN_MASK (1 << UART_CTL_RXPAREN_SHIFT)
> +#define UART_CTL_TXPAREVEN_SHIFT 18
> +#define UART_CTL_TXPAREVEN_MASK (1 << UART_CTL_TXPAREVEN_SHIFT)
> +#define UART_CTL_TXPAREN_SHIFT 19
> +#define UART_CTL_TXPAREN_MASK (1 << UART_CTL_TXPAREN_SHIFT)
> +#define UART_CTL_LOOPBACK_SHIFT 20
> +#define UART_CTL_LOOPBACK_MASK (1 << UART_CTL_LOOPBACK_SHIFT)
> +#define UART_CTL_RXEN_SHIFT 21
> +#define UART_CTL_RXEN_MASK (1 << UART_CTL_RXEN_SHIFT)
> +#define UART_CTL_TXEN_SHIFT 22
> +#define UART_CTL_TXEN_MASK (1 << UART_CTL_TXEN_SHIFT)
> +#define UART_CTL_BRGEN_SHIFT 23
> +#define UART_CTL_BRGEN_MASK (1 << UART_CTL_BRGEN_SHIFT)
> +
> +/* UART Baudword register */
> +#define UART_BAUD_REG 0x4
> +
> +/* UART FIFO Config register */
> +#define UART_FIFO_CFG_REG 0x8
> +#define UART_FIFO_CFG_RX_SHIFT 8
> +#define UART_FIFO_CFG_RX_MASK (0xf << UART_FIFO_CFG_RX_SHIFT)
> +#define UART_FIFO_CFG_TX_SHIFT 12
> +#define UART_FIFO_CFG_TX_MASK (0xf << UART_FIFO_CFG_TX_SHIFT)
> +
> +/* UART Interrupt register */
> +#define UART_IR_REG 0x10
> +#define UART_IR_STAT(x) (1 << (x))
> +#define UART_IR_TXEMPTY 5
> +#define UART_IR_RXOVER 7
> +#define UART_IR_RXNOTEMPTY 11
> +
> +/* UART FIFO register */
> +#define UART_FIFO_REG 0x14
> +#define UART_FIFO_VALID_MASK 0xff
> +#define UART_FIFO_FRAMEERR_SHIFT 8
> +#define UART_FIFO_FRAMEERR_MASK (1 << UART_FIFO_FRAMEERR_SHIFT)
> +#define UART_FIFO_PARERR_SHIFT 9
> +#define UART_FIFO_PARERR_MASK (1 << UART_FIFO_PARERR_SHIFT)
> +#define UART_FIFO_BRKDET_SHIFT 10
> +#define UART_FIFO_BRKDET_MASK (1 << UART_FIFO_BRKDET_SHIFT)
> +#define UART_FIFO_ANYERR_MASK (UART_FIFO_FRAMEERR_MASK | \
> + UART_FIFO_PARERR_MASK | \
> + UART_FIFO_BRKDET_MASK)
> +
> +struct bcm6345_serial_priv {
> + void __iomem *base;
> + ulong uartclk;
> +};
> +
> +/*
> + * enable rx & tx operation on uart
> + */
> +static void bcm6345_serial_enable(void __iomem *base)
> +{
> + u32 val;
> +
> + val = __raw_readl(base + UART_CTL_REG);
> + val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
> + __raw_writel(val, base + UART_CTL_REG);

please use the generic I/O accessors like readl and setbits_32 (or
readl_be and setbits_be32 since you have selected CONFIG_SWAP_IO_SPACE
in your SoC config).

This would be shorter and cleaner:

static void bcm6345_serial_enable(void __iomem *base)
{
setbits_be32(base + UART_CTL_REG, UART_CTL_BRGEN_MASK |
UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
}

> +}
> +
> +/*
> + * disable rx & tx operation on uart
> + */
> +static void bcm6345_serial_disable(void __iomem *base)
> +{
> + u32 val;
> +
> + val = __raw_readl(base + UART_CTL_REG);
> + val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
> + UART_CTL_RXEN_MASK);
> + __raw_writel(val, base + UART_CTL_REG);
> +}
> +
> +/*
> + * clear all unread data in rx fifo and unsent data in tx fifo
> + */
> +static void bcm6345_serial_flush(void __iomem *base)
> +{
> + u32 val;
> +
> + /* empty rx and tx fifo */
> + val = __raw_readl(base + UART_CTL_REG);
> + val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
> + __raw_writel(val, base + UART_CTL_REG);
> +
> + /* read any pending char to make sure all irq status are cleared */
> + __raw_readl(base + UART_FIFO_REG);
> +}
> +
> +static int bcm6345_serial_init(void __iomem *base, ulong clk, u32 baudrate)
> +{
> + u32 val;
> +
> + /* mask all irq and flush port */
> + bcm6345_serial_disable(base);
> + bcm6345_serial_flush(base);
> +
> + val = __raw_readl(base + UART_CTL_REG);
> + /* set rx timeout */
> + val &= ~UART_CTL_RXTIMEOUT_MASK;
> + val |= 0x5;
> + /* set stop bits */
> + val &= ~UART_CTL_STOPBITS_MASK;
> + val |= UART_CTL_STOPBITS_1;
> + /* set bits per symbol */
> + val &= ~UART_CTL_BITSPERSYM_MASK;
> + val |= (3 << UART_CTL_BITSPERSYM_SHIFT);
> + /* clear xmit break */
> + val &= ~UART_CTL_XMITBRK_MASK;
> + /* clear reserved bit */
> + val &= ~UART_CTL_RSVD_MASK;
> + /* disable parity */
> + val |= UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK;
> + val &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
> + /* disable loopback */
> + val &= ~UART_CTL_LOOPBACK_MASK;
> + __raw_writel(val, base + UART_CTL_REG);
> +
> + val = __raw_readl(base + UART_FIFO_CFG_REG);
> + /* set rx fifo config */
> + val &= ~UART_FIFO_CFG_RX_MASK;
> + val |= (4 << UART_FIFO_CFG_RX_SHIFT);
> + /* set tx fifo config */
> + val &= ~UART_FIFO_CFG_TX_MASK;
> + val |= (4 << UART_FIFO_CFG_TX_SHIFT);
> + __raw_writel(val, base + UART_FIFO_CFG_REG);
> +
> + /* set baud rate */
> + val = (clk / baudrate) / 16;
> + if (val & 0x1)
> + val = val;
> + else
> + val = val / 2 - 1;
> + __raw_writel(val, base + UART_BAUD_REG);
> +
> + /* clear interrupts */
> + __raw_writel(0, base + UART_IR_REG);
> +
> + /* enable uart */
> + bcm6345_serial_enable(base);
> +
> + return 0;
> +}
> +
> +static int bcm6345_serial_pending(struct udevice *dev, bool input)
> +{
> + struct bcm6345_serial_priv *priv = dev_get_priv(dev);
> + u32 val = __raw_readl(priv->base + UART_IR_REG);
> +
> + if (input)
> + return (val & UART_IR_STAT(UART_IR_RXNOTEMPTY)) ? 1 : 0;
> + else
> + return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 0 : 1;
> +}
> +
> +static int bcm6345_serial_setbrg(struct udevice *dev, int baudrate)
> +{
> + struct bcm6345_serial_priv *priv = dev_get_priv(dev);
> +
> + return bcm6345_serial_init(priv->base, priv->uartclk, baudrate);
> +}
> +
> +static int bcm6345_serial_putc(struct udevice *dev, const char ch)
> +{
> + struct bcm6345_serial_priv *priv = dev_get_priv(dev);
> + u32 val;
> +
> + val = __raw_readl(priv->base + UART_IR_REG);
> + if (!(val & UART_IR_STAT(UART_IR_TXEMPTY)))
> + return -EAGAIN;
> +
> + __raw_writel(ch, priv->base + UART_FIFO_REG);
> +
> + return 0;
> +}
> +
> +static int bcm6345_serial_getc(struct udevice *dev)
> +{
> + struct bcm6345_serial_priv *priv = dev_get_priv(dev);
> + u32 val;
> +
> + val = __raw_readl(priv->base + UART_IR_REG);
> + if (val & UART_IR_STAT(UART_IR_RXOVER)) {
> + /* fifo reset is required to clear interrupt */
> + val = __raw_readl(priv->base + UART_CTL_REG);
> + val |= UART_CTL_RSTRXFIFO_MASK;
> + __raw_writel(val, priv->base + UART_CTL_REG);
> + }
> + if (!(val & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
> + return -EAGAIN;
> +
> + val = __raw_readl(priv->base + UART_FIFO_REG);
> + if (val & UART_FIFO_ANYERR_MASK)
> + return -EAGAIN;
> +
> + return (val & UART_FIFO_VALID_MASK);

checkpatch.pl: ERROR: return is not a function, parentheses are not required

> +}
> +
> +static int bcm6345_serial_probe(struct udevice *dev)
> +{
> + struct bcm6345_serial_priv *priv = dev_get_priv(dev);
> + struct clk clk;
> + fdt_addr_t addr;
> + fdt_size_t size;
> + int ret;
> +
> + /* get address */
> + addr = dev_get_addr_size_index(dev, 0, &size);
> + if (addr == FDT_ADDR_T_NONE)
> + return -EINVAL;
> +
> + priv->base = ioremap(addr, size);
> +
> + /* get clock rate */
> + ret = clk_get_by_index(dev, 0, &clk);
> + if (ret < 0)
> + return ret;
> + priv->uartclk = clk_get_rate(&clk) / 2;
> + clk_free(&clk);
> +
> + /* initialize serial */
> + return bcm6345_serial_init(priv->base, priv->uartclk, CONFIG_BAUDRATE);
> +}
> +
> +static const struct dm_serial_ops bcm6345_serial_ops = {
> + .putc = bcm6345_serial_putc,
> + .pending = bcm6345_serial_pending,
> + .getc = bcm6345_serial_getc,
> + .setbrg = bcm6345_serial_setbrg,
> +};
> +
> +static const struct udevice_id bcm6345_serial_ids[] = {
> + { .compatible = "brcm,bcm6345-uart" },
> + { /* sentinel */ }
> +};
> +
> +U_BOOT_DRIVER(bcm6345_serial) = {
> + .name = "bcm6345-uart",
> + .id = UCLASS_SERIAL,
> + .of_match = bcm6345_serial_ids,
> + .probe = bcm6345_serial_probe,
> + .priv_auto_alloc_size = sizeof(struct bcm6345_serial_priv),
> + .ops = &bcm6345_serial_ops,
> + .flags = DM_FLAG_PRE_RELOC,
> +};
> +
> +#ifdef CONFIG_DEBUG_UART_BCM6345
> +static inline void _debug_uart_init(void)
> +{
> + void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
> +
> + bcm6345_serial_init(base, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
> +}
> +
> +static inline void wait_xfered(void __iomem *base)
> +{
> + do {
> + u32 val = __raw_readl(base + UART_IR_REG);
> + if (val & UART_IR_STAT(UART_IR_TXEMPTY))
> + break;
> + } while (1);
> +}
> +
> +static inline void _debug_uart_putc(int ch)
> +{
> + void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
> +
> + wait_xfered(base);
> + __raw_writel(ch, base + UART_FIFO_REG);
> + wait_xfered(base);
> +}
> +
> +DEBUG_UART_FUNCS
> +#endif
>

--
- Daniel

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