| // 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/global_data.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; |
| bool force_highspeed; |
| }; |
| |
| static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud) |
| { |
| u32 quot, realbaud, samplecount = 1; |
| |
| /* Special case for low baud clock */ |
| if (baud <= 115200 && priv->clock <= 12000000) { |
| 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); |
| |
| 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); |
| } |
| |
| goto set_baud; |
| } |
| |
| if (priv->force_highspeed) |
| goto use_hs3; |
| |
| if (baud <= 115200) { |
| writel(0, &priv->regs->highspeed); |
| quot = DIV_ROUND_CLOSEST(priv->clock, 16 * baud); |
| } 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 { |
| use_hs3: |
| writel(3, &priv->regs->highspeed); |
| |
| quot = DIV_ROUND_UP(priv->clock, 256 * baud); |
| samplecount = DIV_ROUND_CLOSEST(priv->clock, quot * baud); |
| } |
| |
| set_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); |
| |
| /* set highspeed mode sample count & point */ |
| 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') |
| schedule(); |
| |
| 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_of_to_plat(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; |
| } |
| |
| priv->force_highspeed = dev_read_bool(dev, "mediatek,force-highspeed"); |
| |
| 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, |
| .of_to_plat = mtk_serial_of_to_plat, |
| .priv_auto = 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) \ |
| schedule(); \ |
| } 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_VAL(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_VAL(DEBUG_UART_BASE); |
| |
| while (!(readl(®s->lsr) & UART_LSR_THRE)) |
| ; |
| |
| writel(ch, ®s->thr); |
| } |
| |
| DEBUG_UART_FUNCS |
| |
| #endif |