diff options
Diffstat (limited to 'target/linux/cns3xxx/files/drivers/spi')
-rw-r--r-- | target/linux/cns3xxx/files/drivers/spi/spi-cns3xxx.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/target/linux/cns3xxx/files/drivers/spi/spi-cns3xxx.c b/target/linux/cns3xxx/files/drivers/spi/spi-cns3xxx.c new file mode 100644 index 0000000..6301986 --- /dev/null +++ b/target/linux/cns3xxx/files/drivers/spi/spi-cns3xxx.c @@ -0,0 +1,448 @@ +/******************************************************************************* + * + * CNS3XXX SPI controller driver (master mode only) + * + * Copyright (c) 2008 Cavium Networks + * Copyright 2011 Gateworks Corporation + * Chris Lang <clang@gateworks.com> + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, Version 2, as + * published by the Free Software Foundation. + * + * This file is distributed in the hope that it will be useful, + * but AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or + * NONINFRINGEMENT. See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA or + * visit http://www.gnu.org/licenses/. + * + * This file may also be available under a different license from Cavium. + * Contact Cavium Networks for more information + * + ******************************************************************************/ + +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/platform_device.h> + +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/mtd/partitions.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> + +#include <asm/io.h> +#include <asm/memory.h> +#include <asm/dma.h> +#include <asm/delay.h> +#include <linux/module.h> + +/* + * define access macros + */ +#define SPI_MEM_MAP_VALUE(reg_offset) (*((u32 volatile *)(hw->base + reg_offset))) + +#define SPI_CONFIGURATION_REG SPI_MEM_MAP_VALUE(0x00) +#define SPI_SERVICE_STATUS_REG SPI_MEM_MAP_VALUE(0x04) +#define SPI_BIT_RATE_CONTROL_REG SPI_MEM_MAP_VALUE(0x08) +#define SPI_TRANSMIT_CONTROL_REG SPI_MEM_MAP_VALUE(0x0C) +#define SPI_TRANSMIT_BUFFER_REG SPI_MEM_MAP_VALUE(0x10) +#define SPI_RECEIVE_CONTROL_REG SPI_MEM_MAP_VALUE(0x14) +#define SPI_RECEIVE_BUFFER_REG SPI_MEM_MAP_VALUE(0x18) +#define SPI_FIFO_TRANSMIT_CONFIG_REG SPI_MEM_MAP_VALUE(0x1C) +#define SPI_FIFO_TRANSMIT_CONTROL_REG SPI_MEM_MAP_VALUE(0x20) +#define SPI_FIFO_RECEIVE_CONFIG_REG SPI_MEM_MAP_VALUE(0x24) +#define SPI_INTERRUPT_STATUS_REG SPI_MEM_MAP_VALUE(0x28) +#define SPI_INTERRUPT_ENABLE_REG SPI_MEM_MAP_VALUE(0x2C) + +#define SPI_TRANSMIT_BUFFER_REG_ADDR (CNS3XXX_SSP_BASE +0x10) +#define SPI_RECEIVE_BUFFER_REG_ADDR (CNS3XXX_SSP_BASE +0x18) + +/* Structure for SPI controller of CNS3XXX SOCs */ +struct cns3xxx_spi { + /* bitbang has to be first */ + struct spi_bitbang bitbang; + struct completion done; + wait_queue_head_t wait; + + int len; + int count; + int last_in_message_list; + + /* data buffers */ + const unsigned char *tx; + unsigned char *rx; + + void __iomem *base; + struct spi_master *master; + struct platform_device *pdev; + struct device *dev; +}; + +static inline u8 cns3xxx_spi_bus_idle(struct cns3xxx_spi *hw) +{ + return ((SPI_SERVICE_STATUS_REG & 0x1) ? 0 : 1); +} + +static inline u8 cns3xxx_spi_tx_buffer_empty(struct cns3xxx_spi *hw) +{ + return ((SPI_INTERRUPT_STATUS_REG & (0x1 << 3)) ? 1 : 0); +} + +static inline u8 cns3xxx_spi_rx_buffer_full(struct cns3xxx_spi *hw) +{ + return ((SPI_INTERRUPT_STATUS_REG & (0x1 << 2)) ? 1 : 0); +} + +u8 cns3xxx_spi_tx_rx(struct cns3xxx_spi *hw, u8 tx_channel, u8 tx_eof, + u32 tx_data, u32 * rx_data) +{ + u8 rx_channel; + u8 rx_eof; + + while (!cns3xxx_spi_bus_idle(hw)) ; // do nothing + + while (!cns3xxx_spi_tx_buffer_empty(hw)) ; // do nothing + + SPI_TRANSMIT_CONTROL_REG &= ~(0x7); + SPI_TRANSMIT_CONTROL_REG |= (tx_channel & 0x3) | ((tx_eof & 0x1) << 2); + + SPI_TRANSMIT_BUFFER_REG = tx_data; + + while (!cns3xxx_spi_rx_buffer_full(hw)) ; // do nothing + + rx_channel = SPI_RECEIVE_CONTROL_REG & 0x3; + rx_eof = (SPI_RECEIVE_CONTROL_REG & (0x1 << 2)) ? 1 : 0; + + *rx_data = SPI_RECEIVE_BUFFER_REG; + + if ((tx_channel != rx_channel) || (tx_eof != rx_eof)) { + return 0; + } else { + return 1; + } +} + +u8 cns3xxx_spi_tx(struct cns3xxx_spi *hw, u8 tx_channel, u8 tx_eof, u32 tx_data) +{ + + while (!cns3xxx_spi_bus_idle(hw)) ; // do nothing + + while (!cns3xxx_spi_tx_buffer_empty(hw)) ; // do nothing + + SPI_TRANSMIT_CONTROL_REG &= ~(0x7); + SPI_TRANSMIT_CONTROL_REG |= (tx_channel & 0x3) | ((tx_eof & 0x1) << 2); + + SPI_TRANSMIT_BUFFER_REG = tx_data; + + return 1; +} + +static inline struct cns3xxx_spi *to_hw(struct spi_device *sdev) +{ + return spi_master_get_devdata(sdev->master); +} + +static int cns3xxx_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + return 0; +} + +static void cns3xxx_spi_chipselect(struct spi_device *spi, int value) +{ + struct cns3xxx_spi *hw = to_hw(spi); + unsigned int spi_config; + + switch (value) { + case BITBANG_CS_INACTIVE: + break; + + case BITBANG_CS_ACTIVE: + spi_config = SPI_CONFIGURATION_REG; + + if (spi->mode & SPI_CPHA) + spi_config |= (0x1 << 13); + else + spi_config &= ~(0x1 << 13); + + if (spi->mode & SPI_CPOL) + spi_config |= (0x1 << 14); + else + spi_config &= ~(0x1 << 14); + + /* write new configration */ + SPI_CONFIGURATION_REG = spi_config; + + SPI_TRANSMIT_CONTROL_REG &= ~(0x7); + SPI_TRANSMIT_CONTROL_REG |= (spi->chip_select & 0x3); + + break; + } +} + +static int cns3xxx_spi_setup(struct spi_device *spi) +{ + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + return 0; +} + +static int cns3xxx_spi_txrx(struct spi_device *spi, struct spi_transfer *t) +{ + struct cns3xxx_spi *hw = to_hw(spi); + + dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", t->tx_buf, t->rx_buf, + t->len); + + hw->tx = t->tx_buf; + hw->rx = t->rx_buf; + hw->len = t->len; + hw->count = 0; + hw->last_in_message_list = t->last_in_message_list; + + init_completion(&hw->done); + + if (hw->tx) { + int i; + u32 rx_data; + for (i = 0; i < (hw->len - 1); i++) { + dev_dbg(&spi->dev, + "[SPI_CNS3XXX_DEBUG] hw->tx[%02d]: 0x%02x\n", i, + hw->tx[i]); + cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, hw->tx[i], + &rx_data); + if (hw->rx) { + hw->rx[i] = rx_data; + dev_dbg(&spi->dev, + "[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n", + i, hw->rx[i]); + } + } + + if (t->last_in_message_list) { + cns3xxx_spi_tx_rx(hw, spi->chip_select, 1, hw->tx[i], + &rx_data); + if (hw->rx) { + hw->rx[i] = rx_data; + dev_dbg(&spi->dev, + "[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n", + i, hw->rx[i]); + } + } else { + cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, hw->tx[i], + &rx_data); + } + goto done; + } + + if (hw->rx) { + int i; + u32 rx_data; + for (i = 0; i < (hw->len - 1); i++) { + cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, 0xff, &rx_data); + hw->rx[i] = rx_data; + dev_dbg(&spi->dev, + "[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n", i, + hw->rx[i]); + } + + if (t->last_in_message_list) { + cns3xxx_spi_tx_rx(hw, spi->chip_select, 1, 0xff, &rx_data); + } else { + cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, 0xff, &rx_data); + } + hw->rx[i] = rx_data; + dev_dbg(&spi->dev, "[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n", + i, hw->rx[i]); + } +done: + return hw->len; +} + +static void __init cns3xxx_spi_initial(struct cns3xxx_spi *hw) +{ + SPI_CONFIGURATION_REG = (((0x0 & 0x3) << 0) | /* 8bits shift length */ + (0x0 << 9) | /* SPI mode */ + (0x0 << 10) | /* disable FIFO */ + (0x1 << 11) | /* SPI master mode */ + (0x0 << 12) | /* disable SPI loopback mode */ + (0x1 << 13) | /* clock phase */ + (0x1 << 14) | /* clock polarity */ + (0x0 << 24) | /* disable - SPI data swap */ + (0x1 << 29) | /* enable - 2IO Read mode */ + (0x0 << 30) | /* disable - SPI high speed read for system boot up */ + (0x0 << 31)); /* disable - SPI */ + + /* Set SPI bit rate PCLK/2 */ + SPI_BIT_RATE_CONTROL_REG = 0x1; + + /* Set SPI Tx channel 0 */ + SPI_TRANSMIT_CONTROL_REG = 0x0; + + /* Set Tx FIFO Threshold, Tx FIFO has 2 words */ + SPI_FIFO_TRANSMIT_CONFIG_REG &= ~(0x03 << 4); + SPI_FIFO_TRANSMIT_CONFIG_REG |= ((0x0 & 0x03) << 4); + + /* Set Rx FIFO Threshold, Rx FIFO has 2 words */ + SPI_FIFO_RECEIVE_CONFIG_REG &= ~(0x03 << 4); + SPI_FIFO_RECEIVE_CONFIG_REG |= ((0x0 & 0x03) << 4); + + /* Disable all interrupt */ + SPI_INTERRUPT_ENABLE_REG = 0x0; + + /* Clear spurious interrupt sources */ + SPI_INTERRUPT_STATUS_REG = (0x0F << 4); + + /* Enable SPI */ + SPI_CONFIGURATION_REG |= (0x1 << 31); + + return; +} + +static int cns3xxx_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct cns3xxx_spi *hw; + struct resource *res; + int err = 0; + + printk("%s: setup CNS3XXX SPI Controller\n", __FUNCTION__); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + /* Allocate master with space for cns3xxx_spi */ + master = spi_alloc_master(&pdev->dev, sizeof(struct cns3xxx_spi)); + if (master == NULL) { + dev_err(&pdev->dev, "No memory for spi_master\n"); + err = -ENOMEM; + goto err_nomem; + } + + hw = spi_master_get_devdata(master); + memset(hw, 0, sizeof(struct cns3xxx_spi)); + + hw->master = spi_master_get(master); + hw->dev = &pdev->dev; + + hw->base = devm_ioremap_resource(hw->dev, res); + if (IS_ERR(hw->base)) { + dev_err(hw->dev, "Unable to map registers\n"); + err = PTR_ERR(hw->base); + goto err_register; + } + + platform_set_drvdata(pdev, hw); + init_completion(&hw->done); + + /* setup the master state. */ + + master->num_chipselect = 4; + master->bus_num = 1; + + /* setup the state for the bitbang driver */ + + hw->bitbang.master = hw->master; + hw->bitbang.setup_transfer = cns3xxx_spi_setup_transfer; + hw->bitbang.chipselect = cns3xxx_spi_chipselect; + hw->bitbang.txrx_bufs = cns3xxx_spi_txrx; + hw->bitbang.master->setup = cns3xxx_spi_setup; + + dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang); + + /* SPI controller initializations */ + cns3xxx_spi_initial(hw); + + /* register SPI controller */ + + err = spi_bitbang_start(&hw->bitbang); + if (err) { + dev_err(&pdev->dev, "Failed to register SPI master\n"); + goto err_register; + } + + return 0; + +err_register: + spi_master_put(hw->master);; + +err_nomem: + return err; +} + +static int cns3xxx_spi_remove(struct platform_device *dev) +{ + struct cns3xxx_spi *hw = platform_get_drvdata(dev); + + platform_set_drvdata(dev, NULL); + + spi_unregister_master(hw->master); + + spi_master_put(hw->master); + return 0; +} + +#ifdef CONFIG_PM + +static int cns3xxx_spi_suspend(struct platform_device *pdev, pm_message_t msg) +{ + struct cns3xxx_spi *hw = platform_get_drvdata(pdev); + + return 0; +} + +static int cns3xxx_spi_resume(struct platform_device *pdev) +{ + struct cns3xxx_spi *hw = platform_get_drvdata(pdev); + + return 0; +} + +#else +#define cns3xxx_spi_suspend NULL +#define cns3xxx_spi_resume NULL +#endif + +static struct platform_driver cns3xxx_spi_driver = { + .probe = cns3xxx_spi_probe, + .remove = cns3xxx_spi_remove, + .suspend = cns3xxx_spi_suspend, + .resume = cns3xxx_spi_resume, + .driver = { + .name = "cns3xxx_spi", + .owner = THIS_MODULE, + }, +}; + +static int __init cns3xxx_spi_init(void) +{ + return platform_driver_register(&cns3xxx_spi_driver); +} + +static void __exit cns3xxx_spi_exit(void) +{ + platform_driver_unregister(&cns3xxx_spi_driver); +} + +module_init(cns3xxx_spi_init); +module_exit(cns3xxx_spi_exit); + +MODULE_AUTHOR("Cavium Networks"); +MODULE_DESCRIPTION("CNS3XXX SPI Controller Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:cns3xxx_spi"); + +EXPORT_SYMBOL_GPL(cns3xxx_spi_tx_rx); |