mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-17 07:28:51 +09:00
![Bin Meng](/assets/img/avatar_default.png)
When a driver declares DM_FLAG_PRE_RELOC flag, it wishes to be bound before relocation. However due to a bug in the DM core, the flag only takes effect when devices are statically declared via U_BOOT_DEVICE(). This bug has been fixed recently by commit "dm: core: Respect drivers with the DM_FLAG_PRE_RELOC flag in lists_bind_fdt()", but with the fix, it has a side effect that all existing drivers that declared DM_FLAG_PRE_RELOC flag will be bound before relocation now. This may expose potential boot failure on some boards due to insufficient memory during the pre-relocation stage. To mitigate this potential impact, the following changes are implemented: - Remove DM_FLAG_PRE_RELOC flag in the driver, if the driver only supports configuration from device tree (OF_CONTROL) - Keep DM_FLAG_PRE_RELOC flag in the driver only if the device is statically declared via U_BOOT_DEVICE() - Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check, for drivers that support both statically declared devices and configuration from device tree Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
199 lines
4.5 KiB
C
199 lines
4.5 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* (c) 2015 Paul Thacker <paul.thacker@microchip.com>
|
|
*
|
|
*/
|
|
#include <common.h>
|
|
#include <clk.h>
|
|
#include <dm.h>
|
|
#include <serial.h>
|
|
#include <wait_bit.h>
|
|
#include <mach/pic32.h>
|
|
#include <dt-bindings/clock/microchip,clock.h>
|
|
|
|
DECLARE_GLOBAL_DATA_PTR;
|
|
|
|
/* UART Control Registers */
|
|
#define U_MOD 0x00
|
|
#define U_MODCLR (U_MOD + _CLR_OFFSET)
|
|
#define U_MODSET (U_MOD + _SET_OFFSET)
|
|
#define U_STA 0x10
|
|
#define U_STACLR (U_STA + _CLR_OFFSET)
|
|
#define U_STASET (U_STA + _SET_OFFSET)
|
|
#define U_TXR 0x20
|
|
#define U_RXR 0x30
|
|
#define U_BRG 0x40
|
|
|
|
/* U_MOD bits */
|
|
#define UART_ENABLE BIT(15)
|
|
|
|
/* U_STA bits */
|
|
#define UART_RX_ENABLE BIT(12)
|
|
#define UART_TX_BRK BIT(11)
|
|
#define UART_TX_ENABLE BIT(10)
|
|
#define UART_TX_FULL BIT(9)
|
|
#define UART_TX_EMPTY BIT(8)
|
|
#define UART_RX_OVER BIT(1)
|
|
#define UART_RX_DATA_AVAIL BIT(0)
|
|
|
|
struct pic32_uart_priv {
|
|
void __iomem *base;
|
|
ulong uartclk;
|
|
};
|
|
|
|
/*
|
|
* Initialize the serial port with the given baudrate.
|
|
* The settings are always 8 data bits, no parity, 1 stop bit, no start bits.
|
|
*/
|
|
static int pic32_serial_init(void __iomem *base, ulong clk, u32 baudrate)
|
|
{
|
|
u32 div = DIV_ROUND_CLOSEST(clk, baudrate * 16);
|
|
|
|
/* wait for TX FIFO to empty */
|
|
wait_for_bit_le32(base + U_STA, UART_TX_EMPTY,
|
|
true, CONFIG_SYS_HZ, false);
|
|
|
|
/* send break */
|
|
writel(UART_TX_BRK, base + U_STASET);
|
|
|
|
/* disable and clear mode */
|
|
writel(0, base + U_MOD);
|
|
writel(0, base + U_STA);
|
|
|
|
/* set baud rate generator */
|
|
writel(div - 1, base + U_BRG);
|
|
|
|
/* enable the UART for TX and RX */
|
|
writel(UART_TX_ENABLE | UART_RX_ENABLE, base + U_STASET);
|
|
|
|
/* enable the UART */
|
|
writel(UART_ENABLE, base + U_MODSET);
|
|
return 0;
|
|
}
|
|
|
|
/* Check whether any char pending in RX fifo */
|
|
static int pic32_uart_pending_input(void __iomem *base)
|
|
{
|
|
/* check if rx buffer overrun error has occurred */
|
|
if (readl(base + U_STA) & UART_RX_OVER) {
|
|
readl(base + U_RXR);
|
|
|
|
/* clear overrun error to keep receiving */
|
|
writel(UART_RX_OVER, base + U_STACLR);
|
|
}
|
|
|
|
/* In PIC32 there is no way to know number of outstanding
|
|
* chars in rx-fifo. Only it can be known whether there is any.
|
|
*/
|
|
return readl(base + U_STA) & UART_RX_DATA_AVAIL;
|
|
}
|
|
|
|
static int pic32_uart_pending(struct udevice *dev, bool input)
|
|
{
|
|
struct pic32_uart_priv *priv = dev_get_priv(dev);
|
|
|
|
if (input)
|
|
return pic32_uart_pending_input(priv->base);
|
|
|
|
return !(readl(priv->base + U_STA) & UART_TX_EMPTY);
|
|
}
|
|
|
|
static int pic32_uart_setbrg(struct udevice *dev, int baudrate)
|
|
{
|
|
struct pic32_uart_priv *priv = dev_get_priv(dev);
|
|
|
|
return pic32_serial_init(priv->base, priv->uartclk, baudrate);
|
|
}
|
|
|
|
static int pic32_uart_putc(struct udevice *dev, const char ch)
|
|
{
|
|
struct pic32_uart_priv *priv = dev_get_priv(dev);
|
|
|
|
/* Check if Tx FIFO is full */
|
|
if (readl(priv->base + U_STA) & UART_TX_FULL)
|
|
return -EAGAIN;
|
|
|
|
/* pump the char to tx buffer */
|
|
writel(ch, priv->base + U_TXR);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pic32_uart_getc(struct udevice *dev)
|
|
{
|
|
struct pic32_uart_priv *priv = dev_get_priv(dev);
|
|
|
|
/* return error if RX fifo is empty */
|
|
if (!pic32_uart_pending_input(priv->base))
|
|
return -EAGAIN;
|
|
|
|
/* read the character from rx buffer */
|
|
return readl(priv->base + U_RXR) & 0xff;
|
|
}
|
|
|
|
static int pic32_uart_probe(struct udevice *dev)
|
|
{
|
|
struct pic32_uart_priv *priv = dev_get_priv(dev);
|
|
struct clk clk;
|
|
fdt_addr_t addr;
|
|
fdt_size_t size;
|
|
int ret;
|
|
|
|
/* get address */
|
|
addr = fdtdec_get_addr_size(gd->fdt_blob, dev_of_offset(dev), "reg",
|
|
&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);
|
|
clk_free(&clk);
|
|
|
|
/* initialize serial */
|
|
return pic32_serial_init(priv->base, priv->uartclk, CONFIG_BAUDRATE);
|
|
}
|
|
|
|
static const struct dm_serial_ops pic32_uart_ops = {
|
|
.putc = pic32_uart_putc,
|
|
.pending = pic32_uart_pending,
|
|
.getc = pic32_uart_getc,
|
|
.setbrg = pic32_uart_setbrg,
|
|
};
|
|
|
|
static const struct udevice_id pic32_uart_ids[] = {
|
|
{ .compatible = "microchip,pic32mzda-uart" },
|
|
{}
|
|
};
|
|
|
|
U_BOOT_DRIVER(pic32_serial) = {
|
|
.name = "pic32-uart",
|
|
.id = UCLASS_SERIAL,
|
|
.of_match = pic32_uart_ids,
|
|
.probe = pic32_uart_probe,
|
|
.ops = &pic32_uart_ops,
|
|
.priv_auto_alloc_size = sizeof(struct pic32_uart_priv),
|
|
};
|
|
|
|
#ifdef CONFIG_DEBUG_UART_PIC32
|
|
#include <debug_uart.h>
|
|
|
|
static inline void _debug_uart_init(void)
|
|
{
|
|
void __iomem *base = (void __iomem *)CONFIG_DEBUG_UART_BASE;
|
|
|
|
pic32_serial_init(base, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
|
|
}
|
|
|
|
static inline void _debug_uart_putc(int ch)
|
|
{
|
|
writel(ch, CONFIG_DEBUG_UART_BASE + U_TXR);
|
|
}
|
|
|
|
DEBUG_UART_FUNCS
|
|
#endif
|