/* * (C) Copyright 2009 SAMSUNG Electronics * Minkyu Kang * Heungjun Kim * * based on drivers/serial/s3c64xx.c * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include #include #include #include #include DECLARE_GLOBAL_DATA_PTR; #define RX_FIFO_COUNT_MASK 0xff #define RX_FIFO_FULL_MASK (1 << 8) #define TX_FIFO_FULL_MASK (1 << 24) /* Information about a serial port */ struct fdt_serial { u32 base_addr; /* address of registers in physical memory */ u8 port_id; /* uart port number */ u8 enabled; /* 1 if enabled, 0 if disabled */ } config __attribute__ ((section(".data"))); static inline struct s5p_uart *s5p_get_base_uart(int dev_index) { #ifdef CONFIG_OF_CONTROL return (struct s5p_uart *)(config.base_addr); #else u32 offset = dev_index * sizeof(struct s5p_uart); return (struct s5p_uart *)(samsung_get_base_uart() + offset); #endif } /* * The coefficient, used to calculate the baudrate on S5P UARTs is * calculated as * C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT * however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1, * 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants: */ static const int udivslot[] = { 0, 0x0080, 0x0808, 0x0888, 0x2222, 0x4924, 0x4a52, 0x54aa, 0x5555, 0xd555, 0xd5d5, 0xddd5, 0xdddd, 0xdfdd, 0xdfdf, 0xffdf, }; static void serial_setbrg_dev(const int dev_index) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); u32 uclk = get_uart_clk(dev_index); u32 baudrate = gd->baudrate; u32 val; #if defined(CONFIG_SILENT_CONSOLE) && \ defined(CONFIG_OF_CONTROL) && \ !defined(CONFIG_SPL_BUILD) if (fdtdec_get_config_int(gd->fdt_blob, "silent_console", 0)) gd->flags |= GD_FLG_SILENT; #endif if (!config.enabled) return; val = uclk / baudrate; writel(val / 16 - 1, &uart->ubrdiv); if (s5p_uart_divslot()) writew(udivslot[val % 16], &uart->rest.slot); else writeb(val % 16, &uart->rest.value); } /* * 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 serial_init_dev(const int dev_index) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); /* enable FIFOs, auto clear Rx FIFO */ writel(0x3, &uart->ufcon); writel(0, &uart->umcon); /* 8N1 */ writel(0x3, &uart->ulcon); /* No interrupts, no DMA, pure polling */ writel(0x245, &uart->ucon); serial_setbrg_dev(dev_index); return 0; } static int serial_err_check(const int dev_index, int op) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); unsigned int mask; /* * UERSTAT * Break Detect [3] * Frame Err [2] : receive operation * Parity Err [1] : receive operation * Overrun Err [0] : receive operation */ if (op) mask = 0x8; else mask = 0xf; return readl(&uart->uerstat) & mask; } /* * Read a single byte from the serial port. Returns 1 on success, 0 * otherwise. When the function is succesfull, the character read is * written into its argument c. */ static int serial_getc_dev(const int dev_index) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); if (!config.enabled) return 0; /* wait for character to arrive */ while (!(readl(&uart->ufstat) & (RX_FIFO_COUNT_MASK | RX_FIFO_FULL_MASK))) { if (serial_err_check(dev_index, 0)) return 0; } return (int)(readb(&uart->urxh) & 0xff); } /* * Output a single byte to the serial port. */ static void serial_putc_dev(const char c, const int dev_index) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); if (!config.enabled) return; /* wait for room in the tx FIFO */ while ((readl(&uart->ufstat) & TX_FIFO_FULL_MASK)) { if (serial_err_check(dev_index, 1)) return; } writeb(c, &uart->utxh); /* If \n, also do \r */ if (c == '\n') serial_putc('\r'); } /* * Test whether a character is in the RX buffer */ static int serial_tstc_dev(const int dev_index) { struct s5p_uart *const uart = s5p_get_base_uart(dev_index); if (!config.enabled) return 0; return (int)(readl(&uart->utrstat) & 0x1); } static void serial_puts_dev(const char *s, const int dev_index) { while (*s) serial_putc_dev(*s++, dev_index); } /* Multi serial device functions */ #define DECLARE_S5P_SERIAL_FUNCTIONS(port) \ static int s5p_serial##port##_init(void) { return serial_init_dev(port); } \ static void s5p_serial##port##_setbrg(void) { serial_setbrg_dev(port); } \ static int s5p_serial##port##_getc(void) { return serial_getc_dev(port); } \ static int s5p_serial##port##_tstc(void) { return serial_tstc_dev(port); } \ static void s5p_serial##port##_putc(const char c) { serial_putc_dev(c, port); } \ static void s5p_serial##port##_puts(const char *s) { serial_puts_dev(s, port); } #define INIT_S5P_SERIAL_STRUCTURE(port, __name) { \ .name = __name, \ .start = s5p_serial##port##_init, \ .stop = NULL, \ .setbrg = s5p_serial##port##_setbrg, \ .getc = s5p_serial##port##_getc, \ .tstc = s5p_serial##port##_tstc, \ .putc = s5p_serial##port##_putc, \ .puts = s5p_serial##port##_puts, \ } DECLARE_S5P_SERIAL_FUNCTIONS(0); struct serial_device s5p_serial0_device = INIT_S5P_SERIAL_STRUCTURE(0, "s5pser0"); DECLARE_S5P_SERIAL_FUNCTIONS(1); struct serial_device s5p_serial1_device = INIT_S5P_SERIAL_STRUCTURE(1, "s5pser1"); DECLARE_S5P_SERIAL_FUNCTIONS(2); struct serial_device s5p_serial2_device = INIT_S5P_SERIAL_STRUCTURE(2, "s5pser2"); DECLARE_S5P_SERIAL_FUNCTIONS(3); struct serial_device s5p_serial3_device = INIT_S5P_SERIAL_STRUCTURE(3, "s5pser3"); #ifdef CONFIG_OF_CONTROL int fdtdec_decode_console(int *index, struct fdt_serial *uart) { const void *blob = gd->fdt_blob; int node; node = fdt_path_offset(blob, "console"); if (node < 0) return node; uart->base_addr = fdtdec_get_addr(blob, node, "reg"); if (uart->base_addr == FDT_ADDR_T_NONE) return -FDT_ERR_NOTFOUND; uart->port_id = fdtdec_get_int(blob, node, "id", -1); uart->enabled = fdtdec_get_is_enabled(blob, node); return 0; } #endif __weak struct serial_device *default_serial_console(void) { #ifdef CONFIG_OF_CONTROL int index = 0; if ((!config.base_addr) && (fdtdec_decode_console(&index, &config))) { debug("Cannot decode default console node\n"); return NULL; } switch (config.port_id) { case 0: return &s5p_serial0_device; case 1: return &s5p_serial1_device; case 2: return &s5p_serial2_device; case 3: return &s5p_serial3_device; default: debug("Unknown config.port_id: %d", config.port_id); break; } return NULL; #else config.enabled = 1; #if defined(CONFIG_SERIAL0) return &s5p_serial0_device; #elif defined(CONFIG_SERIAL1) return &s5p_serial1_device; #elif defined(CONFIG_SERIAL2) return &s5p_serial2_device; #elif defined(CONFIG_SERIAL3) return &s5p_serial3_device; #else #error "CONFIG_SERIAL? missing." #endif #endif } void s5p_serial_initialize(void) { serial_register(&s5p_serial0_device); serial_register(&s5p_serial1_device); serial_register(&s5p_serial2_device); serial_register(&s5p_serial3_device); }