uart.c

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/* Source : APQ8064 LK boot */
/* SPDX-License-Identifier: BSD-3-Clause */
 
#include <device/mmio.h>
#include <boot/coreboot_tables.h>
#include <console/uart.h>
#include <delay.h>
#include <gpio.h>
#include <soc/clock.h>
#include <soc/blsp.h>
#include <soc/ipq_uart.h>
#include <stdint.h>
 
#define FIFO_DATA_SIZE  4
 
typedef struct {
        void *uart_dm_base;
        uart_clk_mnd_t mnd_value;
        unsigned int blsp_uart;
        gpio_func_data_t dbg_uart_gpio[NO_OF_DBG_UART_GPIOS];
} uart_params_t;
 
static const uart_params_t uart_board_param = {
        .uart_dm_base = UART1_DM_BASE,
        .mnd_value = { 24, 625, 313 },
        .blsp_uart = BLSP1_UART1,
        .dbg_uart_gpio = {
                {
#if CONFIG(IPQ_QFN_PART)
                        .gpio = 60,
                        .func = 2,
#else   /* bga */
                        .gpio = 16,
                        .func = 1,
#endif
                        .dir = GPIO_INPUT,
                        .pull = GPIO_NO_PULL,
                        .enable = GPIO_ENABLE
                },
                {
#if CONFIG(IPQ_QFN_PART)
                        .gpio = 61,
                        .func = 2,
#else   /* bga */
                        .gpio = 17,
                        .func = 1,
#endif
                        .dir = GPIO_OUTPUT,
                        .pull = GPIO_NO_PULL,
                        .enable = GPIO_ENABLE
                },
        },
};
 
/**
 * @brief msm_boot_uart_dm_init_rx_transfer - Init Rx transfer
 * @param uart_dm_base: UART controller base address
 */
static unsigned int msm_boot_uart_dm_init_rx_transfer(void *uart_dm_base)
{
        /* Reset receiver */
        write32(MSM_BOOT_UART_DM_CR(uart_dm_base),
                MSM_BOOT_UART_DM_CMD_RESET_RX);
 
        /* Enable receiver */
        write32(MSM_BOOT_UART_DM_CR(uart_dm_base),
                MSM_BOOT_UART_DM_CR_RX_ENABLE);
        write32(MSM_BOOT_UART_DM_DMRX(uart_dm_base),
                MSM_BOOT_UART_DM_DMRX_DEF_VALUE);
 
        /* Clear stale event */
        write32(MSM_BOOT_UART_DM_CR(uart_dm_base),
                MSM_BOOT_UART_DM_CMD_RES_STALE_INT);
 
        /* Enable stale event */
        write32(MSM_BOOT_UART_DM_CR(uart_dm_base),
                MSM_BOOT_UART_DM_GCMD_ENA_STALE_EVT);
 
        return MSM_BOOT_UART_DM_E_SUCCESS;
}
 
static unsigned int msm_boot_uart_dm_init(void  *uart_dm_base);
 
/* Received data is valid or not */
static int valid_data = 0;
 
/* Received data */
static unsigned int word = 0;
 
void uart_tx_byte(unsigned int idx, unsigned char data)
{
        int num_of_chars = 1;
        void *base = uart_board_param.uart_dm_base;
 
        /* Wait until transmit FIFO is empty. */
        while (!(read32(MSM_BOOT_UART_DM_SR(base)) &
                 MSM_BOOT_UART_DM_SR_TXEMT))
                udelay(1);
        /*
         * TX FIFO is ready to accept new character(s). First write number of
         * characters to be transmitted.
         */
        write32(MSM_BOOT_UART_DM_NO_CHARS_FOR_TX(base), num_of_chars);
 
        /* And now write the character(s) */
        write32(MSM_BOOT_UART_DM_TF(base, 0), data);
}
 
/**
 * @brief msm_boot_uart_dm_reset - resets UART controller
 * @param base: UART controller base address
 */
static unsigned int msm_boot_uart_dm_reset(void *base)
{
        write32(MSM_BOOT_UART_DM_CR(base), MSM_BOOT_UART_DM_CMD_RESET_RX);
        write32(MSM_BOOT_UART_DM_CR(base), MSM_BOOT_UART_DM_CMD_RESET_TX);
        write32(MSM_BOOT_UART_DM_CR(base),
                MSM_BOOT_UART_DM_CMD_RESET_ERR_STAT);
        write32(MSM_BOOT_UART_DM_CR(base), MSM_BOOT_UART_DM_CMD_RES_TX_ERR);
        write32(MSM_BOOT_UART_DM_CR(base), MSM_BOOT_UART_DM_CMD_RES_STALE_INT);
 
        return MSM_BOOT_UART_DM_E_SUCCESS;
}
 
/**
 * @brief msm_boot_uart_dm_init - initilaizes UART controller
 * @param uart_dm_base: UART controller base address
 */
unsigned int msm_boot_uart_dm_init(void  *uart_dm_base)
{
        /* Configure UART mode registers MR1 and MR2 */
        /* Hardware flow control isn't supported */
        write32(MSM_BOOT_UART_DM_MR1(uart_dm_base), 0x0);
 
        /* 8-N-1 configuration: 8 data bits - No parity - 1 stop bit */
        write32(MSM_BOOT_UART_DM_MR2(uart_dm_base),
                MSM_BOOT_UART_DM_8_N_1_MODE);
 
        /* Configure Interrupt Mask register IMR */
        write32(MSM_BOOT_UART_DM_IMR(uart_dm_base),
                MSM_BOOT_UART_DM_IMR_ENABLED);
 
        /*
         * Configure Tx and Rx watermarks configuration registers
         * TX watermark value is set to 0 - interrupt is generated when
         * FIFO level is less than or equal to 0
         */
        write32(MSM_BOOT_UART_DM_TFWR(uart_dm_base),
                MSM_BOOT_UART_DM_TFW_VALUE);
 
        /* RX watermark value */
        write32(MSM_BOOT_UART_DM_RFWR(uart_dm_base),
                MSM_BOOT_UART_DM_RFW_VALUE);
 
        /* Configure Interrupt Programming Register */
        /* Set initial Stale timeout value */
        write32(MSM_BOOT_UART_DM_IPR(uart_dm_base),
                MSM_BOOT_UART_DM_STALE_TIMEOUT_LSB);
 
        /* Configure IRDA if required */
        /* Disabling IRDA mode */
        write32(MSM_BOOT_UART_DM_IRDA(uart_dm_base), 0x0);
 
        /* Configure hunt character value in HCR register */
        /* Keep it in reset state */
        write32(MSM_BOOT_UART_DM_HCR(uart_dm_base), 0x0);
 
        /*
         * Configure Rx FIFO base address
         * Both TX/RX shares same SRAM and default is half-n-half.
         * Sticking with default value now.
         * As such RAM size is (2^RAM_ADDR_WIDTH, 32-bit entries).
         * We have found RAM_ADDR_WIDTH = 0x7f
         */
 
        /* Issue soft reset command */
        msm_boot_uart_dm_reset(uart_dm_base);
 
        /* Enable/Disable Rx/Tx DM interfaces */
        /* Data Mover not currently utilized. */
        write32(MSM_BOOT_UART_DM_DMEN(uart_dm_base), 0x0);
 
        /* Enable transmitter */
        write32(MSM_BOOT_UART_DM_CR(uart_dm_base),
                MSM_BOOT_UART_DM_CR_TX_ENABLE);
 
        /* Initialize Receive Path */
        msm_boot_uart_dm_init_rx_transfer(uart_dm_base);
 
        return 0;
}
 
/**
 * @brief ipq40xx_uart_init - initializes UART
 *
 * Initializes clocks, GPIO and UART controller.
 */
void uart_init(unsigned int idx)
{
        /* Note int idx isn't used in this driver. */
        void *dm_base;
 
        dm_base = uart_board_param.uart_dm_base;
 
        if (read32(MSM_BOOT_UART_DM_CSR(dm_base)) == UART_DM_CLK_RX_TX_BIT_RATE)
                return; /* UART must have been already initialized. */
 
        ipq_configure_gpio(uart_board_param.dbg_uart_gpio,
                           NO_OF_DBG_UART_GPIOS);
 
        /* Configure the uart clock */
        uart_clock_config(uart_board_param.blsp_uart,
                uart_board_param.mnd_value.m_value,
                uart_board_param.mnd_value.n_value,
                uart_board_param.mnd_value.d_value);
 
        write32(MSM_BOOT_UART_DM_CSR(dm_base), UART_DM_CLK_RX_TX_BIT_RATE);
 
        /* Initialize UART_DM */
        msm_boot_uart_dm_init(dm_base);
}
 
/* for the benefit of non-console uart init */
void ipq40xx_uart_init(void)
{
        uart_init(0);
}
 
/**
 * @brief uart_tx_flush - transmits a string of data
 * @param idx: string to transmit
 */
void uart_tx_flush(unsigned int idx)
{
        void *base = uart_board_param.uart_dm_base;
 
        while (!(read32(MSM_BOOT_UART_DM_SR(base)) &
                 MSM_BOOT_UART_DM_SR_TXEMT))
                ;
}
 
/**
 * ipq40xx_serial_getc - reads a character
 *
 * Returns the character read from serial port.
 */
uint8_t uart_rx_byte(unsigned int idx)
{
        uint8_t byte;
 
        byte = (uint8_t)(word & 0xff);
        word = word >> 8;
        valid_data--;
 
        return byte;
}
 
/* TODO: Implement function */
void uart_fill_lb(void *data)
{
        struct lb_serial serial;
 
        serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
        serial.baseaddr = (uint32_t)UART1_DM_BASE;
        serial.baud = get_uart_baudrate();
        serial.regwidth = 1;
        serial.input_hertz = uart_platform_refclk();
        serial.uart_pci_addr = CONFIG_UART_PCI_ADDR;
        lb_add_serial(&serial, data);
 
        lb_add_console(LB_TAG_CONSOLE_SERIAL8250MEM, data);
}