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- // SPDX-License-Identifier: GPL-2.0
- /*
- * MediaTek High-speed UART driver
- *
- * Copyright (C) 2018 MediaTek Inc.
- * Author: Weijie Gao <weijie.gao@mediatek.com>
- */
- #include <clk.h>
- #include <common.h>
- #include <div64.h>
- #include <dm.h>
- #include <errno.h>
- #include <log.h>
- #include <serial.h>
- #include <watchdog.h>
- #include <asm/io.h>
- #include <asm/types.h>
- #include <linux/err.h>
- struct mtk_serial_regs {
- u32 rbr;
- u32 ier;
- u32 fcr;
- u32 lcr;
- u32 mcr;
- u32 lsr;
- u32 msr;
- u32 spr;
- u32 mdr1;
- u32 highspeed;
- u32 sample_count;
- u32 sample_point;
- u32 fracdiv_l;
- u32 fracdiv_m;
- u32 escape_en;
- u32 guard;
- u32 rx_sel;
- };
- #define thr rbr
- #define iir fcr
- #define dll rbr
- #define dlm ier
- #define UART_LCR_WLS_8 0x03 /* 8 bit character length */
- #define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
- #define UART_LSR_DR 0x01 /* Data ready */
- #define UART_LSR_THRE 0x20 /* Xmit holding register empty */
- #define UART_LSR_TEMT 0x40 /* Xmitter empty */
- #define UART_MCR_DTR 0x01 /* DTR */
- #define UART_MCR_RTS 0x02 /* RTS */
- #define UART_FCR_FIFO_EN 0x01 /* Fifo enable */
- #define UART_FCR_RXSR 0x02 /* Receiver soft reset */
- #define UART_FCR_TXSR 0x04 /* Transmitter soft reset */
- #define UART_MCRVAL (UART_MCR_DTR | \
- UART_MCR_RTS)
- /* Clear & enable FIFOs */
- #define UART_FCRVAL (UART_FCR_FIFO_EN | \
- UART_FCR_RXSR | \
- UART_FCR_TXSR)
- /* the data is correct if the real baud is within 3%. */
- #define BAUD_ALLOW_MAX(baud) ((baud) + (baud) * 3 / 100)
- #define BAUD_ALLOW_MIX(baud) ((baud) - (baud) * 3 / 100)
- struct mtk_serial_priv {
- struct mtk_serial_regs __iomem *regs;
- u32 clock;
- };
- static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud)
- {
- bool support_clk12m_baud115200;
- u32 quot, samplecount, realbaud;
- if ((baud <= 115200) && (priv->clock == 12000000))
- support_clk12m_baud115200 = true;
- else
- support_clk12m_baud115200 = false;
- if (baud <= 115200) {
- writel(0, &priv->regs->highspeed);
- quot = DIV_ROUND_CLOSEST(priv->clock, 16 * baud);
- if (support_clk12m_baud115200) {
- writel(3, &priv->regs->highspeed);
- quot = DIV_ROUND_CLOSEST(priv->clock, 256 * baud);
- if (quot == 0)
- quot = 1;
- samplecount = DIV_ROUND_CLOSEST(priv->clock,
- quot * baud);
- if (samplecount != 0) {
- realbaud = priv->clock / samplecount / quot;
- if ((realbaud > BAUD_ALLOW_MAX(baud)) ||
- (realbaud < BAUD_ALLOW_MIX(baud))) {
- pr_info("baud %d can't be handled\n",
- baud);
- }
- } else {
- pr_info("samplecount is 0\n");
- }
- }
- } else if (baud <= 576000) {
- writel(2, &priv->regs->highspeed);
- /* Set to next lower baudrate supported */
- if ((baud == 500000) || (baud == 576000))
- baud = 460800;
- quot = DIV_ROUND_UP(priv->clock, 4 * baud);
- } else {
- writel(3, &priv->regs->highspeed);
- quot = DIV_ROUND_UP(priv->clock, 256 * baud);
- }
- /* set divisor */
- writel(UART_LCR_WLS_8 | UART_LCR_DLAB, &priv->regs->lcr);
- writel(quot & 0xff, &priv->regs->dll);
- writel((quot >> 8) & 0xff, &priv->regs->dlm);
- writel(UART_LCR_WLS_8, &priv->regs->lcr);
- if (baud > 460800) {
- u32 tmp;
- tmp = DIV_ROUND_CLOSEST(priv->clock, quot * baud);
- writel(tmp - 1, &priv->regs->sample_count);
- writel((tmp - 2) >> 1, &priv->regs->sample_point);
- } else {
- writel(0, &priv->regs->sample_count);
- writel(0xff, &priv->regs->sample_point);
- }
- if (support_clk12m_baud115200) {
- writel(samplecount - 1, &priv->regs->sample_count);
- writel((samplecount - 2) >> 1, &priv->regs->sample_point);
- }
- }
- static int _mtk_serial_putc(struct mtk_serial_priv *priv, const char ch)
- {
- if (!(readl(&priv->regs->lsr) & UART_LSR_THRE))
- return -EAGAIN;
- writel(ch, &priv->regs->thr);
- if (ch == '\n')
- WATCHDOG_RESET();
- return 0;
- }
- static int _mtk_serial_getc(struct mtk_serial_priv *priv)
- {
- if (!(readl(&priv->regs->lsr) & UART_LSR_DR))
- return -EAGAIN;
- return readl(&priv->regs->rbr);
- }
- static int _mtk_serial_pending(struct mtk_serial_priv *priv, bool input)
- {
- if (input)
- return (readl(&priv->regs->lsr) & UART_LSR_DR) ? 1 : 0;
- else
- return (readl(&priv->regs->lsr) & UART_LSR_THRE) ? 0 : 1;
- }
- #if defined(CONFIG_DM_SERIAL) && \
- (!defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_DM))
- static int mtk_serial_setbrg(struct udevice *dev, int baudrate)
- {
- struct mtk_serial_priv *priv = dev_get_priv(dev);
- _mtk_serial_setbrg(priv, baudrate);
- return 0;
- }
- static int mtk_serial_putc(struct udevice *dev, const char ch)
- {
- struct mtk_serial_priv *priv = dev_get_priv(dev);
- return _mtk_serial_putc(priv, ch);
- }
- static int mtk_serial_getc(struct udevice *dev)
- {
- struct mtk_serial_priv *priv = dev_get_priv(dev);
- return _mtk_serial_getc(priv);
- }
- static int mtk_serial_pending(struct udevice *dev, bool input)
- {
- struct mtk_serial_priv *priv = dev_get_priv(dev);
- return _mtk_serial_pending(priv, input);
- }
- static int mtk_serial_probe(struct udevice *dev)
- {
- struct mtk_serial_priv *priv = dev_get_priv(dev);
- /* Disable interrupt */
- writel(0, &priv->regs->ier);
- writel(UART_MCRVAL, &priv->regs->mcr);
- writel(UART_FCRVAL, &priv->regs->fcr);
- return 0;
- }
- static int mtk_serial_ofdata_to_platdata(struct udevice *dev)
- {
- struct mtk_serial_priv *priv = dev_get_priv(dev);
- fdt_addr_t addr;
- struct clk clk;
- int err;
- addr = dev_read_addr(dev);
- if (addr == FDT_ADDR_T_NONE)
- return -EINVAL;
- priv->regs = map_physmem(addr, 0, MAP_NOCACHE);
- err = clk_get_by_index(dev, 0, &clk);
- if (!err) {
- err = clk_get_rate(&clk);
- if (!IS_ERR_VALUE(err))
- priv->clock = err;
- } else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
- debug("mtk_serial: failed to get clock\n");
- return err;
- }
- if (!priv->clock)
- priv->clock = dev_read_u32_default(dev, "clock-frequency", 0);
- if (!priv->clock) {
- debug("mtk_serial: clock not defined\n");
- return -EINVAL;
- }
- return 0;
- }
- static const struct dm_serial_ops mtk_serial_ops = {
- .putc = mtk_serial_putc,
- .pending = mtk_serial_pending,
- .getc = mtk_serial_getc,
- .setbrg = mtk_serial_setbrg,
- };
- static const struct udevice_id mtk_serial_ids[] = {
- { .compatible = "mediatek,hsuart" },
- { .compatible = "mediatek,mt6577-uart" },
- { }
- };
- U_BOOT_DRIVER(serial_mtk) = {
- .name = "serial_mtk",
- .id = UCLASS_SERIAL,
- .of_match = mtk_serial_ids,
- .ofdata_to_platdata = mtk_serial_ofdata_to_platdata,
- .priv_auto_alloc_size = sizeof(struct mtk_serial_priv),
- .probe = mtk_serial_probe,
- .ops = &mtk_serial_ops,
- .flags = DM_FLAG_PRE_RELOC,
- };
- #else
- DECLARE_GLOBAL_DATA_PTR;
- #define DECLARE_HSUART_PRIV(port) \
- static struct mtk_serial_priv mtk_hsuart##port = { \
- .regs = (struct mtk_serial_regs *)CONFIG_SYS_NS16550_COM##port, \
- .clock = CONFIG_SYS_NS16550_CLK \
- };
- #define DECLARE_HSUART_FUNCTIONS(port) \
- static int mtk_serial##port##_init(void) \
- { \
- writel(0, &mtk_hsuart##port.regs->ier); \
- writel(UART_MCRVAL, &mtk_hsuart##port.regs->mcr); \
- writel(UART_FCRVAL, &mtk_hsuart##port.regs->fcr); \
- _mtk_serial_setbrg(&mtk_hsuart##port, gd->baudrate); \
- return 0 ; \
- } \
- static void mtk_serial##port##_setbrg(void) \
- { \
- _mtk_serial_setbrg(&mtk_hsuart##port, gd->baudrate); \
- } \
- static int mtk_serial##port##_getc(void) \
- { \
- int err; \
- do { \
- err = _mtk_serial_getc(&mtk_hsuart##port); \
- if (err == -EAGAIN) \
- WATCHDOG_RESET(); \
- } while (err == -EAGAIN); \
- return err >= 0 ? err : 0; \
- } \
- static int mtk_serial##port##_tstc(void) \
- { \
- return _mtk_serial_pending(&mtk_hsuart##port, true); \
- } \
- static void mtk_serial##port##_putc(const char c) \
- { \
- int err; \
- if (c == '\n') \
- mtk_serial##port##_putc('\r'); \
- do { \
- err = _mtk_serial_putc(&mtk_hsuart##port, c); \
- } while (err == -EAGAIN); \
- } \
- static void mtk_serial##port##_puts(const char *s) \
- { \
- while (*s) { \
- mtk_serial##port##_putc(*s++); \
- } \
- }
- /* Serial device descriptor */
- #define INIT_HSUART_STRUCTURE(port, __name) { \
- .name = __name, \
- .start = mtk_serial##port##_init, \
- .stop = NULL, \
- .setbrg = mtk_serial##port##_setbrg, \
- .getc = mtk_serial##port##_getc, \
- .tstc = mtk_serial##port##_tstc, \
- .putc = mtk_serial##port##_putc, \
- .puts = mtk_serial##port##_puts, \
- }
- #define DECLARE_HSUART(port, __name) \
- DECLARE_HSUART_PRIV(port); \
- DECLARE_HSUART_FUNCTIONS(port); \
- struct serial_device mtk_hsuart##port##_device = \
- INIT_HSUART_STRUCTURE(port, __name);
- #if !defined(CONFIG_CONS_INDEX)
- #elif (CONFIG_CONS_INDEX < 1) || (CONFIG_CONS_INDEX > 6)
- #error "Invalid console index value."
- #endif
- #if CONFIG_CONS_INDEX == 1 && !defined(CONFIG_SYS_NS16550_COM1)
- #error "Console port 1 defined but not configured."
- #elif CONFIG_CONS_INDEX == 2 && !defined(CONFIG_SYS_NS16550_COM2)
- #error "Console port 2 defined but not configured."
- #elif CONFIG_CONS_INDEX == 3 && !defined(CONFIG_SYS_NS16550_COM3)
- #error "Console port 3 defined but not configured."
- #elif CONFIG_CONS_INDEX == 4 && !defined(CONFIG_SYS_NS16550_COM4)
- #error "Console port 4 defined but not configured."
- #elif CONFIG_CONS_INDEX == 5 && !defined(CONFIG_SYS_NS16550_COM5)
- #error "Console port 5 defined but not configured."
- #elif CONFIG_CONS_INDEX == 6 && !defined(CONFIG_SYS_NS16550_COM6)
- #error "Console port 6 defined but not configured."
- #endif
- #if defined(CONFIG_SYS_NS16550_COM1)
- DECLARE_HSUART(1, "mtk-hsuart0");
- #endif
- #if defined(CONFIG_SYS_NS16550_COM2)
- DECLARE_HSUART(2, "mtk-hsuart1");
- #endif
- #if defined(CONFIG_SYS_NS16550_COM3)
- DECLARE_HSUART(3, "mtk-hsuart2");
- #endif
- #if defined(CONFIG_SYS_NS16550_COM4)
- DECLARE_HSUART(4, "mtk-hsuart3");
- #endif
- #if defined(CONFIG_SYS_NS16550_COM5)
- DECLARE_HSUART(5, "mtk-hsuart4");
- #endif
- #if defined(CONFIG_SYS_NS16550_COM6)
- DECLARE_HSUART(6, "mtk-hsuart5");
- #endif
- __weak struct serial_device *default_serial_console(void)
- {
- #if CONFIG_CONS_INDEX == 1
- return &mtk_hsuart1_device;
- #elif CONFIG_CONS_INDEX == 2
- return &mtk_hsuart2_device;
- #elif CONFIG_CONS_INDEX == 3
- return &mtk_hsuart3_device;
- #elif CONFIG_CONS_INDEX == 4
- return &mtk_hsuart4_device;
- #elif CONFIG_CONS_INDEX == 5
- return &mtk_hsuart5_device;
- #elif CONFIG_CONS_INDEX == 6
- return &mtk_hsuart6_device;
- #else
- #error "Bad CONFIG_CONS_INDEX."
- #endif
- }
- void mtk_serial_initialize(void)
- {
- #if defined(CONFIG_SYS_NS16550_COM1)
- serial_register(&mtk_hsuart1_device);
- #endif
- #if defined(CONFIG_SYS_NS16550_COM2)
- serial_register(&mtk_hsuart2_device);
- #endif
- #if defined(CONFIG_SYS_NS16550_COM3)
- serial_register(&mtk_hsuart3_device);
- #endif
- #if defined(CONFIG_SYS_NS16550_COM4)
- serial_register(&mtk_hsuart4_device);
- #endif
- #if defined(CONFIG_SYS_NS16550_COM5)
- serial_register(&mtk_hsuart5_device);
- #endif
- #if defined(CONFIG_SYS_NS16550_COM6)
- serial_register(&mtk_hsuart6_device);
- #endif
- }
- #endif
- #ifdef CONFIG_DEBUG_UART_MTK
- #include <debug_uart.h>
- static inline void _debug_uart_init(void)
- {
- struct mtk_serial_priv priv;
- priv.regs = (void *) CONFIG_DEBUG_UART_BASE;
- priv.clock = CONFIG_DEBUG_UART_CLOCK;
- writel(0, &priv.regs->ier);
- writel(UART_MCRVAL, &priv.regs->mcr);
- writel(UART_FCRVAL, &priv.regs->fcr);
- _mtk_serial_setbrg(&priv, CONFIG_BAUDRATE);
- }
- static inline void _debug_uart_putc(int ch)
- {
- struct mtk_serial_regs __iomem *regs =
- (void *) CONFIG_DEBUG_UART_BASE;
- while (!(readl(®s->lsr) & UART_LSR_THRE))
- ;
- writel(ch, ®s->thr);
- }
- DEBUG_UART_FUNCS
- #endif
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