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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/arm/mach-davinci/serial.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mach-davinci/serial.c')
-rw-r--r-- | arch/arm/mach-davinci/serial.c | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/serial.c b/arch/arm/mach-davinci/serial.c new file mode 100644 index 000000000..7f7814807 --- /dev/null +++ b/arch/arm/mach-davinci/serial.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * TI DaVinci serial driver + * + * Copyright (C) 2006 Texas Instruments. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/serial_8250.h> +#include <linux/serial_reg.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/clk.h> +#include <linux/io.h> + +#include "serial.h" +#include "cputype.h" + +static inline void serial_write_reg(struct plat_serial8250_port *p, int offset, + int value) +{ + offset <<= p->regshift; + + WARN_ONCE(!p->membase, "unmapped write: uart[%d]\n", offset); + + __raw_writel(value, p->membase + offset); +} + +static void __init davinci_serial_reset(struct plat_serial8250_port *p) +{ + unsigned int pwremu = 0; + + serial_write_reg(p, UART_IER, 0); /* disable all interrupts */ + + /* reset both transmitter and receiver: bits 14,13 = UTRST, URRST */ + serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu); + mdelay(10); + + pwremu |= (0x3 << 13); + pwremu |= 0x1; + serial_write_reg(p, UART_DAVINCI_PWREMU, pwremu); + + if (cpu_is_davinci_dm646x()) + serial_write_reg(p, UART_DM646X_SCR, + UART_DM646X_SCR_TX_WATERMARK); +} + +int __init davinci_serial_init(struct platform_device *serial_dev) +{ + int i, ret = 0; + struct device *dev; + struct plat_serial8250_port *p; + struct clk *clk; + + /* + * Make sure the serial ports are muxed on at this point. + * You have to mux them off in device drivers later on if not needed. + */ + for (i = 0; serial_dev[i].dev.platform_data != NULL; i++) { + dev = &serial_dev[i].dev; + p = dev->platform_data; + + ret = platform_device_register(&serial_dev[i]); + if (ret) + continue; + + clk = clk_get(dev, NULL); + if (IS_ERR(clk)) { + pr_err("%s:%d: failed to get UART%d clock\n", + __func__, __LINE__, i); + continue; + } + + clk_prepare_enable(clk); + + p->uartclk = clk_get_rate(clk); + + if (!p->membase && p->mapbase) { + p->membase = ioremap(p->mapbase, SZ_4K); + + if (p->membase) + p->flags &= ~UPF_IOREMAP; + else + pr_err("uart regs ioremap failed\n"); + } + + if (p->membase && p->type != PORT_AR7) + davinci_serial_reset(p); + } + return ret; +} |