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Diffstat (limited to 'src/lib/uart_ipq806.c')
| -rw-r--r-- | src/lib/uart_ipq806.c | 440 |
1 files changed, 440 insertions, 0 deletions
diff --git a/src/lib/uart_ipq806.c b/src/lib/uart_ipq806.c new file mode 100644 index 0000000000..c65f876821 --- /dev/null +++ b/src/lib/uart_ipq806.c @@ -0,0 +1,440 @@ +/* + * Copyright (c) 2012 The Linux Foundation. All rights reserved. + * Source : APQ8064 LK boot + * + * Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google, Inc. nor the names of its contributors + * may be used to endorse or promote products derived from this + * software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + + +#include <common.h> +#include <asm/arch-ipq806x/gsbi.h> +#include <asm/arch-ipq806x/clock.h> +#include <asm/arch-ipq806x/uart.h> +#include <serial.h> + +#define FIFO_DATA_SIZE 4 + +extern board_ipq806x_params_t *gboard_param; + +static unsigned int msm_boot_uart_dm_init(unsigned int uart_dm_base); + +/* Received data is valid or not */ +static int valid_data = 0; + +/* Received data */ +static unsigned int word = 0; + +/** + * msm_boot_uart_dm_init_rx_transfer - Init Rx transfer + * @uart_dm_base: UART controller base address + */ +static unsigned int msm_boot_uart_dm_init_rx_transfer(unsigned int uart_dm_base) +{ + /* Reset receiver */ + writel(MSM_BOOT_UART_DM_CMD_RESET_RX, + MSM_BOOT_UART_DM_CR(uart_dm_base)); + + /* Enable receiver */ + writel(MSM_BOOT_UART_DM_CR_RX_ENABLE, + MSM_BOOT_UART_DM_CR(uart_dm_base)); + writel(MSM_BOOT_UART_DM_DMRX_DEF_VALUE, + MSM_BOOT_UART_DM_DMRX(uart_dm_base)); + + /* Clear stale event */ + writel(MSM_BOOT_UART_DM_CMD_RES_STALE_INT, + MSM_BOOT_UART_DM_CR(uart_dm_base)); + + /* Enable stale event */ + writel(MSM_BOOT_UART_DM_GCMD_ENA_STALE_EVT, + MSM_BOOT_UART_DM_CR(uart_dm_base)); + + return MSM_BOOT_UART_DM_E_SUCCESS; +} + +/** + * msm_boot_uart_dm_read - reads a word from the RX FIFO. + * @data: location where the read data is stored + * @count: no of valid data in the FIFO + * @wait: indicates blocking call or not blocking call + * + * Reads a word from the RX FIFO. If no data is available blocks if + * @wait is true, else returns %MSM_BOOT_UART_DM_E_RX_NOT_READY. + */ +static unsigned int +msm_boot_uart_dm_read(unsigned int *data, int *count, int wait) +{ + static int total_rx_data = 0; + static int rx_data_read = 0; + unsigned int base = 0; + uint32_t status_reg; + + base = gboard_param->uart_dm_base; + + if (data == NULL) + return MSM_BOOT_UART_DM_E_INVAL; + + status_reg = readl(MSM_BOOT_UART_DM_MISR(base)); + + /* Check for DM_RXSTALE for RX transfer to finish */ + while (!(status_reg & MSM_BOOT_UART_DM_RXSTALE)) { + status_reg = readl(MSM_BOOT_UART_DM_MISR(base)); + if (!wait) + return MSM_BOOT_UART_DM_E_RX_NOT_READY; + } + + /* Check for Overrun error. We'll just reset Error Status */ + if (readl(MSM_BOOT_UART_DM_SR(base)) & + MSM_BOOT_UART_DM_SR_UART_OVERRUN) { + writel(MSM_BOOT_UART_DM_CMD_RESET_ERR_STAT, + MSM_BOOT_UART_DM_CR(base)); + total_rx_data = rx_data_read = 0; + msm_boot_uart_dm_init(base); + return MSM_BOOT_UART_DM_E_RX_NOT_READY; + } + + /* Read UART_DM_RX_TOTAL_SNAP for actual number of bytes received */ + if (total_rx_data == 0) + total_rx_data = readl(MSM_BOOT_UART_DM_RX_TOTAL_SNAP(base)); + + /* Data available in FIFO; read a word. */ + *data = readl(MSM_BOOT_UART_DM_RF(base, 0)); + + /* WAR for http://prism/CR/548280 */ + if (*data == 0) { + return MSM_BOOT_UART_DM_E_RX_NOT_READY; + } + + /* increment the total count of chars we've read so far */ + rx_data_read += FIFO_DATA_SIZE; + + /* actual count of valid data in word */ + *count = ((total_rx_data < rx_data_read) ? + (FIFO_DATA_SIZE - (rx_data_read - total_rx_data)) : + FIFO_DATA_SIZE); + + /* If there are still data left in FIFO we'll read them before + * initializing RX Transfer again + */ + if (rx_data_read < total_rx_data) + return MSM_BOOT_UART_DM_E_SUCCESS; + + msm_boot_uart_dm_init_rx_transfer(base); + total_rx_data = rx_data_read = 0; + + return MSM_BOOT_UART_DM_E_SUCCESS; +} + +/** + * msm_boot_uart_replace_lr_with_cr - replaces "\n" with "\r\n" + * @data_in: characters to be converted + * @num_of_chars: no. of characters + * @data_out: location where converted chars are stored + * + * Replace linefeed char "\n" with carriage return + linefeed + * "\r\n". Currently keeping it simple than efficient. + */ +static unsigned int +msm_boot_uart_replace_lr_with_cr(char *data_in, + int num_of_chars, + char *data_out, int *num_of_chars_out) +{ + int i = 0, j = 0; + + if ((data_in == NULL) || (data_out == NULL) || (num_of_chars < 0)) + return MSM_BOOT_UART_DM_E_INVAL; + + for (i = 0, j = 0; i < num_of_chars; i++, j++) { + if (data_in[i] == '\n') + data_out[j++] = '\r'; + + data_out[j] = data_in[i]; + } + + *num_of_chars_out = j; + + return MSM_BOOT_UART_DM_E_SUCCESS; +} + +/** + * msm_boot_uart_dm_write - transmit data + * @data: data to transmit + * @num_of_chars: no. of bytes to transmit + * + * Writes the data to the TX FIFO. If no space is available blocks + * till space becomes available. + */ +static unsigned int +msm_boot_uart_dm_write(char *data, unsigned int num_of_chars) +{ + unsigned int tx_word_count = 0; + unsigned int tx_char_left = 0, tx_char = 0; + unsigned int tx_word = 0; + int i = 0; + char *tx_data = NULL; + char new_data[1024]; + unsigned int base = gboard_param->uart_dm_base; + + if ((data == NULL) || (num_of_chars <= 0)) + return MSM_BOOT_UART_DM_E_INVAL; + + /* Replace line-feed (/n) with carriage-return + line-feed (/r/n) */ + msm_boot_uart_replace_lr_with_cr(data, num_of_chars, new_data, &i); + + tx_data = new_data; + num_of_chars = i; + + /* Write to NO_CHARS_FOR_TX register number of characters + * to be transmitted. However, before writing TX_FIFO must + * be empty as indicated by TX_READY interrupt in IMR register + */ + /* Check if transmit FIFO is empty. + * If not we'll wait for TX_READY interrupt. */ + + if (!(readl(MSM_BOOT_UART_DM_SR(base)) & MSM_BOOT_UART_DM_SR_TXEMT)) { + while (!(readl(MSM_BOOT_UART_DM_ISR(base)) & MSM_BOOT_UART_DM_TX_READY)) + __udelay(1); + } + + /* We are here. FIFO is ready to be written. */ + /* Write number of characters to be written */ + writel(num_of_chars, MSM_BOOT_UART_DM_NO_CHARS_FOR_TX(base)); + + /* Clear TX_READY interrupt */ + writel(MSM_BOOT_UART_DM_GCMD_RES_TX_RDY_INT, MSM_BOOT_UART_DM_CR(base)); + + /* We use four-character word FIFO. So we need to divide data into + * four characters and write in UART_DM_TF register */ + tx_word_count = (num_of_chars % 4) ? ((num_of_chars / 4) + 1) : + (num_of_chars / 4); + tx_char_left = num_of_chars; + + for (i = 0; i < (int)tx_word_count; i++) { + tx_char = (tx_char_left < 4) ? tx_char_left : 4; + PACK_CHARS_INTO_WORDS(tx_data, tx_char, tx_word); + + /* Wait till TX FIFO has space */ + while (!(readl(MSM_BOOT_UART_DM_SR(base)) & MSM_BOOT_UART_DM_SR_TXRDY)) + __udelay(1); + + /* TX FIFO has space. Write the chars */ + writel(tx_word, MSM_BOOT_UART_DM_TF(base, 0)); + tx_char_left = num_of_chars - (i + 1) * 4; + tx_data = tx_data + 4; + } + + return MSM_BOOT_UART_DM_E_SUCCESS; +} + +/* + * msm_boot_uart_dm_reset - resets UART controller + * @base: UART controller base address + */ +static unsigned int msm_boot_uart_dm_reset(unsigned int base) +{ + writel(MSM_BOOT_UART_DM_CMD_RESET_RX, MSM_BOOT_UART_DM_CR(base)); + writel(MSM_BOOT_UART_DM_CMD_RESET_TX, MSM_BOOT_UART_DM_CR(base)); + writel(MSM_BOOT_UART_DM_CMD_RESET_ERR_STAT, MSM_BOOT_UART_DM_CR(base)); + writel(MSM_BOOT_UART_DM_CMD_RES_TX_ERR, MSM_BOOT_UART_DM_CR(base)); + writel(MSM_BOOT_UART_DM_CMD_RES_STALE_INT, MSM_BOOT_UART_DM_CR(base)); + + return MSM_BOOT_UART_DM_E_SUCCESS; +} + +/* + * msm_boot_uart_dm_init - initilaizes UART controller + * @uart_dm_base: UART controller base address + */ +static unsigned int msm_boot_uart_dm_init(unsigned int uart_dm_base) +{ + /* Configure UART mode registers MR1 and MR2 */ + /* Hardware flow control isn't supported */ + writel(0x0, MSM_BOOT_UART_DM_MR1(uart_dm_base)); + + /* 8-N-1 configuration: 8 data bits - No parity - 1 stop bit */ + writel(MSM_BOOT_UART_DM_8_N_1_MODE, MSM_BOOT_UART_DM_MR2(uart_dm_base)); + + /* Configure Interrupt Mask register IMR */ + writel(MSM_BOOT_UART_DM_IMR_ENABLED, MSM_BOOT_UART_DM_IMR(uart_dm_base)); + + /* + * 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 + */ + writel(MSM_BOOT_UART_DM_TFW_VALUE, MSM_BOOT_UART_DM_TFWR(uart_dm_base)); + + /* RX watermark value */ + writel(MSM_BOOT_UART_DM_RFW_VALUE, MSM_BOOT_UART_DM_RFWR(uart_dm_base)); + + /* Configure Interrupt Programming Register */ + /* Set initial Stale timeout value */ + writel(MSM_BOOT_UART_DM_STALE_TIMEOUT_LSB, + MSM_BOOT_UART_DM_IPR(uart_dm_base)); + + /* Configure IRDA if required */ + /* Disabling IRDA mode */ + writel(0x0, MSM_BOOT_UART_DM_IRDA(uart_dm_base)); + + /* Configure hunt character value in HCR register */ + /* Keep it in reset state */ + writel(0x0, MSM_BOOT_UART_DM_HCR(uart_dm_base)); + + /* + * 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. */ + writel(0x0, MSM_BOOT_UART_DM_DMEN(uart_dm_base)); + + /* Enable transmitter */ + writel(MSM_BOOT_UART_DM_CR_TX_ENABLE, + MSM_BOOT_UART_DM_CR(uart_dm_base)); + + /* Initialize Receive Path */ + msm_boot_uart_dm_init_rx_transfer(uart_dm_base); + + return 0; +} + +/** + * uart_dm_init - initializes UART + * + * Initializes clocks, GPIO and UART controller. + */ +static int uart_dm_init(void) +{ + unsigned int dm_base, gsbi_base; + + dm_base = gboard_param->uart_dm_base; + gsbi_base = gboard_param->uart_gsbi_base; + ipq_configure_gpio(gboard_param->dbg_uart_gpio, NO_OF_DBG_UART_GPIOS); + + /* Configure the uart clock */ + uart_clock_config(gboard_param->uart_gsbi, + gboard_param->mnd_value.m_value, + gboard_param->mnd_value.n_value, + gboard_param->mnd_value.d_value, + gboard_param->clk_dummy); + + writel(GSBI_PROTOCOL_CODE_I2C_UART << + GSBI_CTRL_REG_PROTOCOL_CODE_S, + GSBI_CTRL_REG(gsbi_base)); + writel(UART_DM_CLK_RX_TX_BIT_RATE, MSM_BOOT_UART_DM_CSR(dm_base)); + /* Intialize UART_DM */ + msm_boot_uart_dm_init(dm_base); + + return 0; +} + +/** + * ipq806x_serial_putc - transmits a character + * @c: character to transmit + */ +static void ipq806x_serial_putc(char c) +{ + msm_boot_uart_dm_write(&c, 1); +} + +/** + * ipq806x_serial_puts - transmits a string of data + * @s: string to transmit + */ +static void ipq806x_serial_puts(const char *s) +{ + while (*s != '\0') + serial_putc(*s++); +} + +/** + * ipq806x_serial_tstc - checks if data available for reading + * + * Returns 1 if data available, 0 otherwise + */ +static int ipq806x_serial_tstc(void) +{ + /* Return if data is already read */ + if (valid_data) + return 1; + + /* Read data from the FIFO */ + if (msm_boot_uart_dm_read(&word, &valid_data, 0) != MSM_BOOT_UART_DM_E_SUCCESS) + return 0; + + return 1; +} + +/** + * ipq806x_serial_getc - reads a character + * + * Returns the character read from serial port. + */ +static int ipq806x_serial_getc(void) +{ + int byte; + + while (!serial_tstc()) { + /* wait for incoming data */ + } + + byte = (int)word & 0xff; + word = word >> 8; + valid_data--; + + return byte; +} + +static struct serial_device ipq_serial_device = { + .name = "ipq_serial", + .start = uart_dm_init, + .getc = ipq806x_serial_getc, + .tstc = ipq806x_serial_tstc, + .putc = ipq806x_serial_putc, + .puts = ipq806x_serial_puts, +}; + +__weak struct serial_device *default_serial_console(void) +{ + return &ipq_serial_device; +} + +/** + * ipq806x_serial_init - initializes serial controller + */ +void ipq806x_serial_initialize(void) +{ + serial_register(&ipq_serial_device); +} |