88 lines
2.4 KiB
C
88 lines
2.4 KiB
C
// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
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/*
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* Copyright (c) 2023 Rockchip Electronics Co., Ltd.
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*/
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#include <linux/io.h>
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#include "rkpm_helpers.h"
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#include "rkpm_uart.h"
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#define UART_DEFAULT_BAUDRATE 115200
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void rkpm_uart_debug_init(void __iomem *base,
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unsigned int uart_clk,
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unsigned int baud_rate)
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{
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u32 uart_dll, uart_dlh;
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u32 div;
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if (!base || !uart_clk || !baud_rate)
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return;
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div = uart_clk / baud_rate / 16;
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uart_dll = div & 0xff;
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uart_dlh = (div >> 8) & 0xff;
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/* Reset uart */
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writel_relaxed(XMIT_FIFO_RESET | RCVR_FIFO_RESET | UART_RESET,
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base + UARTSRR);
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rkpm_raw_udelay(10);
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writel_relaxed(DIAGNOSTIC_MODE, base + UARTMCR);
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writel_relaxed(0x83, base + UARTLCR);
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writel_relaxed(uart_dll, base + UARTDLL);
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writel_relaxed(uart_dlh, base + UARTDLLM);
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writel_relaxed(0x03, base + UARTLCR);
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writel_relaxed(0x01, base + UARTIER);
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writel_relaxed(UARTFCR_FIFOEN, base + UARTFCR);
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writel_relaxed(0, base + UARTMCR);
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}
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void rkpm_uart_debug_save(void __iomem *base,
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struct uart_debug_ctx *ctx)
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{
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u32 wait_cnt = 50000;
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while ((readl_relaxed(base + UARTUSR) & UARTUSR_BUSY) &&
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--wait_cnt)
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rkpm_raw_udelay(10);
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/* Uart error! Unlikely to reach here */
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if (wait_cnt == 0)
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rkpm_uart_debug_init(base, 24000000, UART_DEFAULT_BAUDRATE);
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ctx->uart_lcr = readl_relaxed(base + UARTLCR);
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ctx->uart_ier = readl_relaxed(base + UARTIER);
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ctx->uart_mcr = readl_relaxed(base + UARTMCR);
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writel_relaxed(ctx->uart_lcr | UARTLCR_DLAB, base + UARTLCR);
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ctx->uart_dll = readl_relaxed(base + UARTDLL);
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ctx->uart_dlh = readl_relaxed(base + UARTDLLM);
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writel_relaxed(ctx->uart_lcr, base + UARTLCR);
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}
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void rkpm_uart_debug_restore(void __iomem *base,
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struct uart_debug_ctx *ctx)
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{
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u32 uart_lcr;
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u32 wait_cnt = 50000;
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while ((readl_relaxed(base + UARTUSR) & UARTUSR_BUSY) &&
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--wait_cnt)
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rkpm_raw_udelay(10);
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writel_relaxed(XMIT_FIFO_RESET | RCVR_FIFO_RESET | UART_RESET,
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base + UARTSRR);
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rkpm_raw_udelay(10);
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uart_lcr = readl_relaxed(base + UARTLCR);
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writel_relaxed(DIAGNOSTIC_MODE, base + UARTMCR);
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writel_relaxed(uart_lcr | UARTLCR_DLAB, base + UARTLCR);
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writel_relaxed(ctx->uart_dll, base + UARTDLL);
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writel_relaxed(ctx->uart_dlh, base + UARTDLLM);
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writel_relaxed(ctx->uart_lcr, base + UARTLCR);
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writel_relaxed(ctx->uart_ier, base + UARTIER);
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writel_relaxed(UARTFCR_FIFOEN, base + UARTFCR);
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writel_relaxed(ctx->uart_mcr, base + UARTMCR);
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}
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