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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/pic32/pic32mzda/early_console.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/pic32/pic32mzda/early_console.c')
-rw-r--r-- | arch/mips/pic32/pic32mzda/early_console.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/mips/pic32/pic32mzda/early_console.c b/arch/mips/pic32/pic32mzda/early_console.c new file mode 100644 index 000000000..3cd1b408f --- /dev/null +++ b/arch/mips/pic32/pic32mzda/early_console.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Joshua Henderson <joshua.henderson@microchip.com> + * Copyright (C) 2015 Microchip Technology Inc. All rights reserved. + */ +#include <asm/mach-pic32/pic32.h> +#include <asm/fw/fw.h> +#include <asm/setup.h> + +#include "pic32mzda.h" +#include "early_pin.h" + +/* Default early console parameters */ +#define EARLY_CONSOLE_PORT 1 +#define EARLY_CONSOLE_BAUDRATE 115200 + +#define UART_ENABLE BIT(15) +#define UART_ENABLE_RX BIT(12) +#define UART_ENABLE_TX BIT(10) +#define UART_TX_FULL BIT(9) + +/* UART1(x == 0) - UART6(x == 5) */ +#define UART_BASE(x) ((x) * 0x0200) +#define U_MODE(x) UART_BASE(x) +#define U_STA(x) (UART_BASE(x) + 0x10) +#define U_TXR(x) (UART_BASE(x) + 0x20) +#define U_BRG(x) (UART_BASE(x) + 0x40) + +static void __iomem *uart_base; +static int console_port = -1; + +static int __init configure_uart_pins(int port) +{ + switch (port) { + case 1: + pic32_pps_input(IN_FUNC_U2RX, IN_RPB0); + pic32_pps_output(OUT_FUNC_U2TX, OUT_RPG9); + break; + case 5: + pic32_pps_input(IN_FUNC_U6RX, IN_RPD0); + pic32_pps_output(OUT_FUNC_U6TX, OUT_RPB8); + break; + default: + return -1; + } + + return 0; +} + +static void __init configure_uart(int port, int baud) +{ + u32 pbclk; + + pbclk = pic32_get_pbclk(2); + + __raw_writel(0, uart_base + U_MODE(port)); + __raw_writel(((pbclk / baud) / 16) - 1, uart_base + U_BRG(port)); + __raw_writel(UART_ENABLE, uart_base + U_MODE(port)); + __raw_writel(UART_ENABLE_TX | UART_ENABLE_RX, + uart_base + PIC32_SET(U_STA(port))); +} + +static void __init setup_early_console(int port, int baud) +{ + if (configure_uart_pins(port)) + return; + + console_port = port; + configure_uart(console_port, baud); +} + +static char * __init pic32_getcmdline(void) +{ + /* + * arch_mem_init() has not been called yet, so we don't have a real + * command line setup if using CONFIG_CMDLINE_BOOL. + */ +#ifdef CONFIG_CMDLINE_OVERRIDE + return CONFIG_CMDLINE; +#else + return fw_getcmdline(); +#endif +} + +static int __init get_port_from_cmdline(char *arch_cmdline) +{ + char *s; + int port = -1; + + if (!arch_cmdline || *arch_cmdline == '\0') + goto _out; + + s = strstr(arch_cmdline, "earlyprintk="); + if (s) { + s = strstr(s, "ttyS"); + if (s) + s += 4; + else + goto _out; + + port = (*s) - '0'; + } + +_out: + return port; +} + +static int __init get_baud_from_cmdline(char *arch_cmdline) +{ + char *s; + int baud = -1; + + if (!arch_cmdline || *arch_cmdline == '\0') + goto _out; + + s = strstr(arch_cmdline, "earlyprintk="); + if (s) { + s = strstr(s, "ttyS"); + if (s) + s += 6; + else + goto _out; + + baud = 0; + while (*s >= '0' && *s <= '9') + baud = baud * 10 + *s++ - '0'; + } + +_out: + return baud; +} + +void __init fw_init_early_console(void) +{ + char *arch_cmdline = pic32_getcmdline(); + int baud, port; + + uart_base = ioremap(PIC32_BASE_UART, 0xc00); + + baud = get_baud_from_cmdline(arch_cmdline); + port = get_port_from_cmdline(arch_cmdline); + + if (port == -1) + port = EARLY_CONSOLE_PORT; + + if (baud == -1) + baud = EARLY_CONSOLE_BAUDRATE; + + setup_early_console(port, baud); +} + +void prom_putchar(char c) +{ + if (console_port >= 0) { + while (__raw_readl( + uart_base + U_STA(console_port)) & UART_TX_FULL) + ; + + __raw_writel(c, uart_base + U_TXR(console_port)); + } +} |