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50cc0c16b7
Move to OMAP specific implementation of certain ops functions as the UART prints on the serial console fail for baudrates greater than 460800. The MDR1 register is responsible for determining the speed mode at which the UART should operate for OMAP specific devices. The baud divisor is used to set the UART_DLL register which is used for generation of the baud clock in the baud rate generator. The implementation logic is similar to how it is implemented in omap_8250_get_divisor function of 8250_omap UART linux driver. Signed-off-by: Gokul Praveen <g-praveen@ti.com> Reviewed-by: Simon Glass <sjg@chromium.org>
225 lines
5.6 KiB
C
225 lines
5.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Texas Instruments' OMAP serial driver
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*
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* Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
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* Lokesh Vutla <lokeshvutla@ti.com>
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*/
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#include <config.h>
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#include <dm.h>
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#include <dt-structs.h>
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#include <log.h>
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#include <ns16550.h>
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#include <serial.h>
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#include <clk.h>
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#include <linux/err.h>
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/*
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* These are the definitions for the MDR1 register
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*/
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#define UART_OMAP_MDR1_16X_MODE 0x00 /* UART 16x mode */
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#define UART_OMAP_MDR1_13X_MODE 0x03 /* UART 13x mode */
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#ifndef CFG_SYS_NS16550_CLK
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#define CFG_SYS_NS16550_CLK 0
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#endif
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#ifdef CONFIG_DEBUG_UART_OMAP
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#ifndef CFG_SYS_NS16550_IER
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#define CFG_SYS_NS16550_IER 0x00
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#endif
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#define UART_MCRVAL 0x00
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#define UART_LCRVAL UART_LCR_8N1
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static inline void serial_out_shift(void *addr, int shift, int value)
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{
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#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
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outb(value, (ulong)addr);
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#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
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out_le32(addr, value);
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#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
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out_be32(addr, value);
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#elif defined(CONFIG_SYS_NS16550_MEM32)
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writel(value, addr);
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#elif defined(CONFIG_SYS_BIG_ENDIAN)
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writeb(value, addr + (1 << shift) - 1);
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#else
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writeb(value, addr);
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#endif
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}
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static inline int serial_in_shift(void *addr, int shift)
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{
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#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
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return inb((ulong)addr);
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#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_LITTLE_ENDIAN)
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return in_le32(addr);
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#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
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return in_be32(addr);
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#elif defined(CONFIG_SYS_NS16550_MEM32)
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return readl(addr);
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#elif defined(CONFIG_SYS_BIG_ENDIAN)
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return readb(addr + (1 << shift) - 1);
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#else
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return readb(addr);
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#endif
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}
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#include <debug_uart.h>
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static inline void _debug_uart_init(void)
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{
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struct ns16550 *com_port = (struct ns16550 *)CONFIG_VAL(DEBUG_UART_BASE);
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int baud_divisor;
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baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
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CONFIG_BAUDRATE);
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serial_dout(&com_port->ier, CFG_SYS_NS16550_IER);
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serial_dout(&com_port->mdr1, 0x7);
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serial_dout(&com_port->mcr, UART_MCRVAL);
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serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
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serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
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serial_dout(&com_port->dll, baud_divisor & 0xff);
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serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
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serial_dout(&com_port->lcr, UART_LCRVAL);
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serial_dout(&com_port->mdr1, 0x0);
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}
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static inline void _debug_uart_putc(int ch)
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{
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struct ns16550 *com_port = (struct ns16550 *)CONFIG_VAL(DEBUG_UART_BASE);
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while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
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;
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serial_dout(&com_port->thr, ch);
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}
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DEBUG_UART_FUNCS
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#endif
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#if CONFIG_IS_ENABLED(DM_SERIAL)
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#if CONFIG_IS_ENABLED(OF_REAL)
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static int omap_serial_of_to_plat(struct udevice *dev)
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{
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struct ns16550_plat *plat = dev_get_plat(dev);
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fdt_addr_t addr;
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struct clk clk;
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int err;
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/* try Processor Local Bus device first */
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addr = dev_read_addr(dev);
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if (addr == FDT_ADDR_T_NONE)
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return -EINVAL;
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plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
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plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
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plat->reg_shift = 2;
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err = clk_get_by_index(dev, 0, &clk);
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if (!err) {
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err = clk_get_rate(&clk);
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if (!IS_ERR_VALUE(err))
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plat->clock = err;
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} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
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debug("omap serial failed to get clock\n");
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return err;
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}
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if (!plat->clock)
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plat->clock = dev_read_u32_default(dev, "clock-frequency",
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CFG_SYS_NS16550_CLK);
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if (!plat->clock) {
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debug("omap serial clock not defined\n");
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return -EINVAL;
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}
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plat->fcr = UART_FCR_DEFVAL;
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return 0;
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}
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static const struct udevice_id omap_serial_ids[] = {
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{ .compatible = "ti,omap2-uart", },
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{ .compatible = "ti,omap3-uart", },
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{ .compatible = "ti,omap4-uart", },
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{ .compatible = "ti,am3352-uart", },
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{ .compatible = "ti,am4372-uart", },
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{ .compatible = "ti,dra742-uart", },
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{ .compatible = "ti,am654-uart", },
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{}
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};
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#endif /* OF_REAL */
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static int omap_serial_calc_divisor(struct ns16550 *com_port, int clock, int baudrate)
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{
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unsigned int div_13, div_16;
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unsigned int abs_d13, abs_d16;
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/*
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* The below logic sets the MDR1 register based on clock and baudrate.
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*/
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div_13 = DIV_ROUND_CLOSEST(clock, 13 * baudrate);
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div_16 = DIV_ROUND_CLOSEST(clock, 16 * baudrate);
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if (!div_13)
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div_13 = 1;
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if (!div_16)
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div_16 = 1;
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abs_d13 = abs(baudrate - clock / 13 / div_13);
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abs_d16 = abs(baudrate - clock / 16 / div_16);
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if (abs_d13 >= abs_d16)
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serial_out(UART_OMAP_MDR1_16X_MODE, &com_port->mdr1);
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else
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serial_out(UART_OMAP_MDR1_13X_MODE, &com_port->mdr1);
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return abs_d13 >= abs_d16 ? div_16 : div_13;
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}
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static int omap_serial_setbrg(struct udevice *dev, int baudrate)
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{
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struct ns16550 *const com_port = dev_get_priv(dev);
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struct ns16550_plat *plat = com_port->plat;
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int clock_divisor;
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clock_divisor = omap_serial_calc_divisor(com_port, plat->clock, baudrate);
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ns16550_setbrg(com_port, clock_divisor);
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return 0;
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}
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const struct dm_serial_ops omap_serial_ops = {
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.putc = ns16550_serial_putc,
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.pending = ns16550_serial_pending,
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.getc = ns16550_serial_getc,
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.setbrg = omap_serial_setbrg,
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.setconfig = ns16550_serial_setconfig,
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.getinfo = ns16550_serial_getinfo,
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};
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#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
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U_BOOT_DRIVER(omap_serial) = {
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.name = "omap_serial",
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.id = UCLASS_SERIAL,
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#if CONFIG_IS_ENABLED(OF_REAL)
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.of_match = omap_serial_ids,
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.of_to_plat = omap_serial_of_to_plat,
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.plat_auto = sizeof(struct ns16550_plat),
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#endif
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.priv_auto = sizeof(struct ns16550),
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.probe = ns16550_serial_probe,
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.ops = &omap_serial_ops,
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#if !CONFIG_IS_ENABLED(OF_CONTROL)
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.flags = DM_FLAG_PRE_RELOC,
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#endif
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};
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#endif
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#endif /* DM_SERIAL */
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