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https://github.com/ARM-software/arm-trusted-firmware.git
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df730d94cb
Provide a helper to detect the enabled UART device during runtime. This lower the integration effort and make it more straight forward for 'simple' use-cases with a single UART enabled. If multiple UARTs are enabled the first enabled is returned. The auto-detection is enabled by setting IMX_BOOT_UART_BASE=0 to keep the backward compatibility. For more advanced use-cases (multiple UARTs are enabled) the user still has to provide the correct base address. Signed-off-by: Marco Felsch <m.felsch@pengutronix.de> Change-Id: I300a167e1a10f9aa991c8d1c3efe2c6b23f56c47
58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
/*
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* Copyright (c) 2023, Pengutronix. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <lib/mmio.h>
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#include <platform_def.h>
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#define UCR1 0x80
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#define UCR1_UARTEN BIT(0)
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#define DOMAIN0_RUNNING(d) (((d) & 0x3) != 0)
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static struct imx_uart {
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unsigned int ccm_reg;
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unsigned int uart_base;
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} imx8m_uart_info[] = {
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{ /* UART 1 */
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.ccm_reg = 0x4490,
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.uart_base = 0x30860000,
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}, { /* UART 2 */
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.ccm_reg = 0x44a0,
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.uart_base = 0x30890000,
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}, { /* UART 3 */
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.ccm_reg = 0x44b0,
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.uart_base = 0x30880000,
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}, { /* UART 4 */
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.ccm_reg = 0x44c0,
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.uart_base = 0x30a60000,
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}
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};
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unsigned int imx8m_uart_get_base(void)
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{
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unsigned int i;
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for (i = 0; i < ARRAY_SIZE(imx8m_uart_info); i++) {
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uint32_t val;
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/*
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* At least check that the clock-gate is ungated before we
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* access the UART register.
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*/
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val = mmio_read_32(IMX_CCM_BASE + imx8m_uart_info[i].ccm_reg);
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if (DOMAIN0_RUNNING(val)) {
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val = mmio_read_32(imx8m_uart_info[i].uart_base + UCR1);
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if (val & UCR1_UARTEN) {
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return imx8m_uart_info[i].uart_base;
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}
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}
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}
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/*
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* We should return an error and inform the user but we can't do it
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* this early.
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*/
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return 0;
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}
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