| /* Copyright (c) 2010-2012, The Linux Foundation. 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 The Linux Foundation 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 "AS IS" AND ANY EXPRESS OR IMPLIED |
| * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT |
| * 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 <string.h> |
| #include <stdlib.h> |
| #include <debug.h> |
| #include <reg.h> |
| #include <sys/types.h> |
| #include <platform/iomap.h> |
| #include <platform/irqs.h> |
| #include <platform/interrupts.h> |
| #include <platform/clock.h> |
| #include <platform/gpio.h> |
| #include <uart_dm.h> |
| #include <gsbi.h> |
| |
| #ifndef NULL |
| #define NULL 0 |
| #endif |
| |
| |
| static int uart_init_flag = 0; |
| |
| /* Note: |
| * This is a basic implementation of UART_DM protocol. More focus has been |
| * given on simplicity than efficiency. Few of the things to be noted are: |
| * - RX path may not be suitable for multi-threaded scenaraio because of the |
| * use of static variables. TX path shouldn't have any problem though. If |
| * multi-threaded support is required, a simple data-structure can |
| * be maintained for each thread. |
| * - Right now we are using polling method than interrupt based. |
| * - We are using legacy UART protocol without Data Mover. |
| * - Not all interrupts and error events are handled. |
| * - While waiting Watchdog hasn't been taken into consideration. |
| */ |
| |
| #define NON_PRINTABLE_ASCII_CHAR 128 |
| |
| static uint8_t pack_chars_into_words(uint8_t *buffer, uint8_t cnt, uint32_t *word) |
| { |
| uint8_t num_chars_writtten = 0; |
| |
| *word = 0; |
| |
| for(int j=0; j < cnt; j++) |
| { |
| if (buffer[num_chars_writtten] == '\n') |
| { |
| /* replace '\n' by the NON_PRINTABLE_ASCII_CHAR and print '\r'. |
| * While printing the NON_PRINTABLE_ASCII_CHAR, we will print '\n'. |
| * Thus successfully replacing '\n' by '\r' '\n'. |
| */ |
| *word |= ('\r' & 0xff) << (j * 8); |
| buffer[num_chars_writtten] = NON_PRINTABLE_ASCII_CHAR; |
| } |
| else |
| { |
| if (buffer[num_chars_writtten] == NON_PRINTABLE_ASCII_CHAR) |
| { |
| buffer[num_chars_writtten] = '\n'; |
| } |
| |
| *word |= (buffer[num_chars_writtten] & 0xff) << (j * 8); |
| |
| num_chars_writtten++; |
| } |
| } |
| |
| return num_chars_writtten; |
| } |
| |
| /* Static Function Prototype Declarations */ |
| static unsigned int msm_boot_uart_calculate_num_chars_to_write(char *data_in, |
| uint32_t *num_of_chars); |
| static unsigned int msm_boot_uart_dm_init(uint32_t base); |
| static unsigned int msm_boot_uart_dm_read(uint32_t base, |
| unsigned int *data, int wait); |
| static unsigned int msm_boot_uart_dm_write(uint32_t base, char *data, |
| unsigned int num_of_chars); |
| static unsigned int msm_boot_uart_dm_init_rx_transfer(uint32_t base); |
| static unsigned int msm_boot_uart_dm_reset(uint32_t base); |
| |
| /* Keep track of uart block vs port mapping. |
| */ |
| static uint32_t port_lookup[4]; |
| |
| /* Extern functions */ |
| void udelay(unsigned usecs); |
| |
| /* |
| * Helper function to keep track of Line Feed char "\n" with |
| * Carriage Return "\r\n". |
| */ |
| static unsigned int |
| msm_boot_uart_calculate_num_chars_to_write(char *data_in, |
| uint32_t *num_of_chars) |
| { |
| int i = 0, j = 0; |
| |
| if ((data_in == 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') { |
| j++; |
| } |
| |
| } |
| |
| *num_of_chars = j; |
| |
| return MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| /* |
| * Reset the UART |
| */ |
| static unsigned int msm_boot_uart_dm_reset(uint32_t 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; |
| } |
| |
| /* |
| * Initialize UART_DM - configure clock and required registers. |
| */ |
| static unsigned int msm_boot_uart_dm_init(uint32_t 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 and enable sim interface if required */ |
| |
| /* 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 and receiver */ |
| writel(MSM_BOOT_UART_DM_CR_RX_ENABLE, MSM_BOOT_UART_DM_CR(uart_dm_base)); |
| 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 MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| /* |
| * Initialize Receive Path |
| */ |
| static unsigned int msm_boot_uart_dm_init_rx_transfer(uint32_t uart_dm_base) |
| { |
| writel(MSM_BOOT_UART_DM_GCMD_DIS_STALE_EVT, MSM_BOOT_UART_DM_CR(uart_dm_base)); |
| writel(MSM_BOOT_UART_DM_CMD_RES_STALE_INT, MSM_BOOT_UART_DM_CR(uart_dm_base)); |
| writel(MSM_BOOT_UART_DM_DMRX_DEF_VALUE, MSM_BOOT_UART_DM_DMRX(uart_dm_base)); |
| writel(MSM_BOOT_UART_DM_GCMD_ENA_STALE_EVT, MSM_BOOT_UART_DM_CR(uart_dm_base)); |
| |
| return MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| /* |
| * UART Receive operation |
| * Reads a word from the RX FIFO. |
| */ |
| static unsigned int |
| msm_boot_uart_dm_read(uint32_t base, unsigned int *data, int wait) |
| { |
| static int rx_last_snap_count = 0; |
| static int rx_chars_read_since_last_xfer = 0; |
| |
| if (data == NULL) { |
| return MSM_BOOT_UART_DM_E_INVAL; |
| } |
| |
| /* We will be polling RXRDY status bit */ |
| while (!(readl(MSM_BOOT_UART_DM_SR(base)) & MSM_BOOT_UART_DM_SR_RXRDY)) { |
| /* if this is not a blocking call, we'll just return */ |
| 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)); |
| } |
| |
| /* RX FIFO is ready; read a word. */ |
| *data = readl(MSM_BOOT_UART_DM_RF(base, 0)); |
| |
| /* increment the total count of chars we've read so far */ |
| rx_chars_read_since_last_xfer += 4; |
| |
| /* Rx transfer ends when one of the conditions is met: |
| * - The number of characters received since the end of the previous |
| * xfer equals the value written to DMRX at Transfer Initialization |
| * - A stale event occurred |
| */ |
| |
| /* If RX transfer has not ended yet */ |
| if (rx_last_snap_count == 0) { |
| /* Check if we've received stale event */ |
| if (readl(MSM_BOOT_UART_DM_MISR(base)) & MSM_BOOT_UART_DM_RXSTALE) { |
| /* Send command to reset stale interrupt */ |
| writel(MSM_BOOT_UART_DM_CMD_RES_STALE_INT, MSM_BOOT_UART_DM_CR(base)); |
| } |
| |
| /* Check if we haven't read more than DMRX value */ |
| else if ((unsigned int)rx_chars_read_since_last_xfer < |
| readl(MSM_BOOT_UART_DM_DMRX(base))) { |
| /* We can still continue reading before initializing RX transfer */ |
| return MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| /* If we've reached here it means RX |
| * xfer end conditions been met |
| */ |
| |
| /* Read UART_DM_RX_TOTAL_SNAP register |
| * to know how many valid chars |
| * we've read so far since last transfer |
| */ |
| rx_last_snap_count = readl(MSM_BOOT_UART_DM_RX_TOTAL_SNAP(base)); |
| |
| } |
| |
| /* If there are still data left in FIFO we'll read them before |
| * initializing RX Transfer again */ |
| if ((rx_last_snap_count - rx_chars_read_since_last_xfer) >= 0) { |
| return MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| msm_boot_uart_dm_init_rx_transfer(base); |
| rx_last_snap_count = 0; |
| rx_chars_read_since_last_xfer = 0; |
| |
| return MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| /* |
| * UART transmit operation |
| */ |
| static unsigned int |
| msm_boot_uart_dm_write(uint32_t base, 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; |
| uint8_t num_chars_written; |
| |
| if ((data == NULL) || (num_of_chars <= 0)) { |
| return MSM_BOOT_UART_DM_E_INVAL; |
| } |
| |
| msm_boot_uart_calculate_num_chars_to_write(data, &num_of_chars); |
| |
| tx_data = data; |
| |
| /* 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); |
| /* Kick watchdog? */ |
| } |
| } |
| |
| /* 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; |
| num_chars_written = 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 + num_chars_written; |
| } |
| |
| return MSM_BOOT_UART_DM_E_SUCCESS; |
| } |
| |
| /* Defining functions that's exposed to outside world and in coformance to |
| * existing uart implemention. These functions are being called to initialize |
| * UART and print debug messages in bootloader. |
| */ |
| void uart_dm_init(uint8_t id, uint32_t gsbi_base, uint32_t uart_dm_base) |
| { |
| static uint8_t port = 0; |
| char *data = "Android Bootloader - UART_DM Initialized!!!\n"; |
| |
| /* Configure the uart clock */ |
| clock_config_uart_dm(id); |
| dsb(); |
| |
| /* Configure GPIO to provide connectivity between UART block |
| product ports and chip pads */ |
| gpio_config_uart_dm(id); |
| dsb(); |
| |
| /* Configure GSBI for UART_DM protocol. |
| * I2C on 2 ports, UART (without HS flow control) on the other 2. |
| * This is only on chips that have GSBI block |
| */ |
| if(gsbi_base) |
| writel(GSBI_PROTOCOL_CODE_I2C_UART << |
| GSBI_CTRL_REG_PROTOCOL_CODE_S, |
| GSBI_CTRL_REG(gsbi_base)); |
| dsb(); |
| |
| /* Configure clock selection register for tx and rx rates. |
| * Selecting 115.2k for both RX and TX. |
| */ |
| writel(UART_DM_CLK_RX_TX_BIT_RATE, MSM_BOOT_UART_DM_CSR(uart_dm_base)); |
| dsb(); |
| |
| /* Intialize UART_DM */ |
| msm_boot_uart_dm_init(uart_dm_base); |
| |
| msm_boot_uart_dm_write(uart_dm_base, data, 44); |
| |
| ASSERT(port < ARRAY_SIZE(port_lookup)); |
| port_lookup[port++] = uart_dm_base; |
| |
| /* Set UART init flag */ |
| uart_init_flag = 1; |
| } |
| |
| /* UART_DM uses four character word FIFO where as UART core |
| * uses a character FIFO. so it's really inefficient to try |
| * to write single character. But that's how dprintf has been |
| * implemented. |
| */ |
| int uart_putc(int port, char c) |
| { |
| uint32_t uart_base = port_lookup[port]; |
| |
| /* Don't do anything if UART is not initialized */ |
| if (!uart_init_flag) |
| return -1; |
| |
| msm_boot_uart_dm_write(uart_base, &c, 1); |
| |
| return 0; |
| } |
| |
| /* UART_DM uses four character word FIFO whereas uart_getc |
| * is supposed to read only one character. So we need to |
| * read a word and keep track of each character in the word. |
| */ |
| int uart_getc(int port, bool wait) |
| { |
| int byte; |
| static unsigned int word = 0; |
| uint32_t uart_base = port_lookup[port]; |
| |
| /* Don't do anything if UART is not initialized */ |
| if (!uart_init_flag) |
| return -1; |
| |
| if (!word) { |
| /* Read from FIFO only if it's a first read or all the four |
| * characters out of a word have been read */ |
| if (msm_boot_uart_dm_read(uart_base, &word, wait) != MSM_BOOT_UART_DM_E_SUCCESS) { |
| return -1; |
| } |
| |
| } |
| |
| byte = (int)word & 0xff; |
| word = word >> 8; |
| |
| return byte; |
| } |