--- /dev/null
+/*
+ * (C) Copyright 2009 SAMSUNG Electronics
+ * Minkyu Kang <mk7.kang@samsung.com>
+ * Heungjun Kim <riverful.kim@samsung.com>
+ *
+ * based on drivers/serial/s3c64xx.c
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <linux/compiler.h>
+#include <asm/io.h>
+#include <asm/arch/uart.h>
+#include <asm/arch/clk.h>
+#include <serial.h>
+
+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);
+}
Code Review / kvmfornfv.git / blobdiff