src/soc/qualcomm/sc7180/qupv3_uart.c

   1 /* This file is part of the coreboot project. */
   2 /* SPDX-License-Identifier: GPL-2.0-only */
   3
   4 #include <assert.h>
   5 #include <boot/coreboot_tables.h>
   6 #include <console/uart.h>
   7 #include <soc/clock.h>
   8 #include <soc/qcom_qup_se.h>
   9 #include <soc/qupv3_config.h>
  10 #include <types.h>
  11
  12 /* COMMON STATUS/CONFIGURATION REGISTERS AND MASKS */
  13
  14 #define GENI_STATUS_M_GENI_CMD_ACTIVE_MASK      0x1
  15 #define GENI_STATUS_S_GENI_CMD_ACTIVE_MASK      0x1000
  16
  17 #define UART_TX_WATERMARK_MARGIN        4       /* Represented in words */
  18 #define UART_RX_WATERMARK_MARGIN        8       /* Represented in words */
  19 #define UART_RX_RFR_WATERMARK_MARGIN    4       /* Represented in words */
  20 #define UART_TX_BITS_PER_WORD   8
  21 #define UART_RX_BITS_PER_WORD   8
  22 #define START_UART_TX           0x8000000
  23 #define START_UART_RX           0x8000000
  24
  25 /* UART FIFO Packing Configuration. */
  26 /* Start_idx:0, direction:0, len:7, stop:0 */
  27 #define UART_TX_PACK_VECTOR0    0x0E
  28 /* Start_idx:8, direction:0, len:7, stop:0 */
  29 #define UART_TX_PACK_VECTOR1    0x10E
  30 /* Start_idx:16, direction:0, len:7, stop:0 */
  31 #define UART_TX_PACK_VECTOR2    0x20E
  32 /* Start_idx:24, direction:0, len:7, stop:1 */
  33 #define UART_TX_PACK_VECTOR3    0x30F
  34 /* Start_idx:0, direction:0, len:7, stop:1 */
  35 #define UART_RX_PACK_VECTOR0    0xF
  36 #define UART_RX_PACK_VECTOR2    0x00
  37
  38 void uart_tx_flush(int idx)
  39 {
  40         struct qup_regs *regs = qup[idx].regs;
  41
  42         while (read32(&regs->geni_status) &
  43                GENI_STATUS_M_GENI_CMD_ACTIVE_MASK)
  44                 ;
  45 }
  46
  47 void uart_init(int idx)
  48 {
  49         struct qup_regs *regs = qup[idx].regs;
  50         unsigned int reg_value;
  51         unsigned int div, baud_rate, uart_freq;
  52
  53         /*
  54          * If the RX (secondary) sequencer is already active, it means the core
  55          * has been already initialized in the previous stage. Skip
  56          * configuration
  57          */
  58         if (read32(&regs->geni_status) & GENI_STATUS_S_GENI_CMD_ACTIVE_MASK)
  59                 return;
  60
  61         qupv3_se_fw_load_and_init(idx, SE_PROTOCOL_UART, FIFO);
  62         clock_enable_qup(idx);
  63
  64         reg_value = read32(&regs->geni_fw_revision_ro);
  65         reg_value &= GENI_FW_REVISION_RO_PROTOCOL_MASK;
  66         reg_value >>= GENI_FW_REVISION_RO_PROTOCOL_SHIFT;
  67
  68         assert(reg_value == SE_PROTOCOL_UART);
  69
  70         baud_rate = get_uart_baudrate();
  71
  72         /* sc7180 requires 16 clock pulses to sample 1 bit of data */
  73         uart_freq = baud_rate * 16;
  74
  75         div = DIV_ROUND_CLOSEST(QUPV3_UART_SRC_HZ, uart_freq);
  76         write32(&regs->geni_ser_m_clk_cfg, (div << 4) | 1);
  77         write32(&regs->geni_ser_s_clk_cfg, (div << 4) | 1);
  78
  79         /* GPIO Configuration */
  80         gpio_configure(qup[idx].pin[2], qup[idx].func[2], GPIO_PULL_UP,
  81                                 GPIO_2MA, GPIO_OUTPUT);
  82         gpio_configure(qup[idx].pin[3], qup[idx].func[3], GPIO_PULL_UP,
  83                                 GPIO_2MA, GPIO_INPUT);
  84
  85         write32(&regs->geni_tx_watermark_reg, UART_TX_WATERMARK_MARGIN);
  86         write32(&regs->geni_rx_watermark_reg, FIFO_DEPTH
  87                                         - UART_RX_WATERMARK_MARGIN);
  88         write32(&regs->geni_rx_rfr_watermark_reg,
  89                         FIFO_DEPTH - UART_RX_RFR_WATERMARK_MARGIN);
  90
  91         write32(&regs->uart_tx_word_len, UART_TX_BITS_PER_WORD);
  92         write32(&regs->uart_rx_word_len, UART_RX_BITS_PER_WORD);
  93
  94         /* Disable TX parity calculation */
  95         write32(&regs->uart_tx_parity_cfg, 0x0);
  96         /* Ignore CTS line status for TX communication */
  97         write32(&regs->uart_tx_trans_cfg_reg, 0x2);
  98         /* Disable RX parity calculation */
  99         write32(&regs->uart_rx_parity_cfg, 0x0);
 100         /* Disable parity, framing and break check on received word */
 101         write32(&regs->uart_rx_trans_cfg, 0x0);
 102         /* Set UART TX stop bit len to one UART bit length */
 103         write32(&regs->uart_tx_stop_bit_len, 0x0);
 104         write32(&regs->uart_rx_stale_cnt, 0x16 * 10);
 105
 106         write32(&regs->geni_tx_packing_cfg0, UART_TX_PACK_VECTOR0 |
 107                                                 (UART_TX_PACK_VECTOR1 << 10));
 108         write32(&regs->geni_tx_packing_cfg1, UART_TX_PACK_VECTOR2 |
 109                                                 (UART_TX_PACK_VECTOR3 << 10));
 110         write32(&regs->geni_rx_packing_cfg0, UART_RX_PACK_VECTOR0);
 111         write32(&regs->geni_rx_packing_cfg1, UART_RX_PACK_VECTOR2);
 112
 113         /* Start RX */
 114         write32(&regs->geni_s_cmd0, START_UART_RX);
 115 }
 116
 117 unsigned char uart_rx_byte(int idx)
 118 {
 119         struct qup_regs *regs = qup[idx].regs;
 120
 121         if (read32(&regs->geni_rx_fifo_status) & RX_FIFO_WC_MSK)
 122                 return read32(&regs->geni_rx_fifon) & 0xFF;
 123         return 0;
 124 }
 125
 126 void uart_tx_byte(int idx, unsigned char data)
 127 {
 128         struct qup_regs *regs = qup[idx].regs;
 129
 130         uart_tx_flush(idx);
 131
 132         write32(&regs->uart_tx_trans_len, 1);
 133         /* Start TX */
 134         write32(&regs->geni_m_cmd0, START_UART_TX);
 135         write32(&regs->geni_tx_fifon, data);
 136 }
 137
 138 uintptr_t uart_platform_base(int idx)
 139 {
 140         return (uintptr_t)qup[idx].regs;
 141 }
 142
 143 void uart_fill_lb(void *data)
 144 {
 145         struct lb_serial serial = {0};
 146
 147         serial.type = LB_SERIAL_TYPE_MEMORY_MAPPED;
 148         serial.baseaddr = (uint32_t)uart_platform_base(CONFIG_UART_FOR_CONSOLE);
 149         serial.baud = get_uart_baudrate();
 150         serial.regwidth = 4;
 151         serial.input_hertz = QUPV3_UART_SRC_HZ;
 152
 153         lb_add_serial(&serial, data);
 154 }