diff options
Diffstat (limited to 'drivers/spi/mxc_spi.c')
| -rw-r--r-- | drivers/spi/mxc_spi.c | 1316 |
1 files changed, 1316 insertions, 0 deletions
diff --git a/drivers/spi/mxc_spi.c b/drivers/spi/mxc_spi.c new file mode 100644 index 000000000000..8e255f48bd7a --- /dev/null +++ b/drivers/spi/mxc_spi.c @@ -0,0 +1,1316 @@ +/* + * Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-licensisr_locke.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @defgroup SPI Configurable Serial Peripheral Interface (CSPI) Driver + */ + +/*! + * @file mxc_spi.c + * @brief This file contains the implementation of the SPI master controller services + * + * + * @ingroup SPI + */ + +#include <linux/slab.h> +#include <linux/completion.h> +#include <linux/platform_device.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/types.h> +#include <linux/clk.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/fsl_devices.h> + +#define MXC_CSPIRXDATA 0x00 +#define MXC_CSPITXDATA 0x04 +#define MXC_CSPICTRL 0x08 +#define MXC_CSPICONFIG 0x08 +#define MXC_CSPIINT 0x0C + +#define MXC_CSPICTRL_DISABLE 0x0 +#define MXC_CSPICTRL_SLAVE 0x0 +#define MXC_CSPICTRL_CSMASK 0x3 +#define MXC_CSPICTRL_SMC (1 << 3) + +#define MXC_CSPIINT_TEEN_SHIFT 0 +#define MXC_CSPIINT_THEN_SHIFT 1 +#define MXC_CSPIINT_TFEN_SHIFT 2 +#define MXC_CSPIINT_RREN_SHIFT 3 +#define MXC_CSPIINT_RHEN_SHIFT 4 +#define MXC_CSPIINT_RFEN_SHIFT 5 +#define MXC_CSPIINT_ROEN_SHIFT 6 + +#define MXC_HIGHPOL 0x0 +#define MXC_NOPHA 0x0 +#define MXC_LOWSSPOL 0x0 + +#define MXC_CSPISTAT_TE 0 +#define MXC_CSPISTAT_TH 1 +#define MXC_CSPISTAT_TF 2 +#define MXC_CSPISTAT_RR 3 +#define MXC_CSPISTAT_RH 4 +#define MXC_CSPISTAT_RF 5 +#define MXC_CSPISTAT_RO 6 + +#define MXC_CSPIPERIOD_32KHZ (1 << 15) + +/*! + * @struct mxc_spi_unique_def + * @brief This structure contains information that differs with + * SPI master controller hardware version + */ +struct mxc_spi_unique_def { + /* Width of valid bits in MXC_CSPIINT */ + unsigned int intr_bit_shift; + /* Chip Select shift */ + unsigned int cs_shift; + /* Bit count shift */ + unsigned int bc_shift; + /* Bit count mask */ + unsigned int bc_mask; + /* Data Control shift */ + unsigned int drctrl_shift; + /* Transfer Complete shift */ + unsigned int xfer_complete; + /* Bit counnter overflow shift */ + unsigned int bc_overflow; + /* FIFO Size */ + unsigned int fifo_size; + /* Control reg address */ + unsigned int ctrl_reg_addr; + /* Status reg address */ + unsigned int stat_reg_addr; + /* Period reg address */ + unsigned int period_reg_addr; + /* Test reg address */ + unsigned int test_reg_addr; + /* Reset reg address */ + unsigned int reset_reg_addr; + /* SPI mode mask */ + unsigned int mode_mask; + /* SPI enable */ + unsigned int spi_enable; + /* XCH bit */ + unsigned int xch; + /* Spi mode shift */ + unsigned int mode_shift; + /* Spi master mode enable */ + unsigned int master_enable; + /* TX interrupt enable diff */ + unsigned int tx_inten_dif; + /* RX interrupt enable bit diff */ + unsigned int rx_inten_dif; + /* Interrupt status diff */ + unsigned int int_status_dif; + /* Low pol shift */ + unsigned int low_pol_shift; + /* Phase shift */ + unsigned int pha_shift; + /* SS control shift */ + unsigned int ss_ctrl_shift; + /* SS pol shift */ + unsigned int ss_pol_shift; + /* Maximum data rate */ + unsigned int max_data_rate; + /* Data mask */ + unsigned int data_mask; + /* Data shift */ + unsigned int data_shift; + /* Loopback control */ + unsigned int lbc; + /* RX count off */ + unsigned int rx_cnt_off; + /* RX count mask */ + unsigned int rx_cnt_mask; + /* Reset start */ + unsigned int reset_start; + /* SCLK control inactive state shift */ + unsigned int sclk_ctl_shift; +}; + +struct mxc_spi; + +/*! + * Structure to group together all the data buffers and functions + * used in data transfers. + */ +struct mxc_spi_xfer { + /* Transmit buffer */ + const void *tx_buf; + /* Receive buffer */ + void *rx_buf; + /* Data transfered count */ + unsigned int count; + /* Data received count, descending sequence, zero means no more data to + be received */ + unsigned int rx_count; + /* Function to read the FIFO data to rx_buf */ + void (*rx_get) (struct mxc_spi *, u32 val); + /* Function to get the data to be written to FIFO */ + u32(*tx_get) (struct mxc_spi *); +}; + +/*! + * This structure is a way for the low level driver to define their own + * \b spi_master structure. This structure includes the core \b spi_master + * structure that is provided by Linux SPI Framework/driver as an + * element and has other elements that are specifically required by this + * low-level driver. + */ +struct mxc_spi { + /* SPI Master and a simple I/O queue runner */ + struct spi_bitbang mxc_bitbang; + /* Completion flags used in data transfers */ + struct completion xfer_done; + /* Data transfer structure */ + struct mxc_spi_xfer transfer; + /* Resource structure, which will maintain base addresses and IRQs */ + struct resource *res; + /* Base address of CSPI, used in readl and writel */ + void *base; + /* CSPI IRQ number */ + int irq; + /* CSPI Clock id */ + struct clk *clk; + /* CSPI input clock SCLK */ + unsigned long spi_ipg_clk; + /* CSPI registers' bit pattern */ + struct mxc_spi_unique_def *spi_ver_def; + /* Control reg address */ + void *ctrl_addr; + /* Status reg address */ + void *stat_addr; + /* Period reg address */ + void *period_addr; + /* Test reg address */ + void *test_addr; + /* Reset reg address */ + void *reset_addr; + /* Chipselect active function */ + void (*chipselect_active) (int cspi_mode, int status, int chipselect); + /* Chipselect inactive function */ + void (*chipselect_inactive) (int cspi_mode, int status, int chipselect); +}; + +#ifdef CONFIG_SPI_MXC_TEST_LOOPBACK +struct spi_chip_info { + int lb_enable; +}; + +static struct spi_chip_info lb_chip_info = { + .lb_enable = 1, +}; + +static struct spi_board_info loopback_info[] = { +#ifdef CONFIG_SPI_MXC_SELECT1 + { + .modalias = "spidev", + .controller_data = &lb_chip_info, + .irq = 0, + .max_speed_hz = 4000000, + .bus_num = 1, + .chip_select = 4, + }, +#endif +#ifdef CONFIG_SPI_MXC_SELECT2 + { + .modalias = "spidev", + .controller_data = &lb_chip_info, + .irq = 0, + .max_speed_hz = 4000000, + .bus_num = 2, + .chip_select = 4, + }, +#endif +#ifdef CONFIG_SPI_MXC_SELECT3 + { + .modalias = "spidev", + .controller_data = &lb_chip_info, + .irq = 0, + .max_speed_hz = 4000000, + .bus_num = 3, + .chip_select = 4, + }, +#endif +}; +#endif + +static struct mxc_spi_unique_def spi_ver_2_3 = { + .intr_bit_shift = 8, + .cs_shift = 18, + .bc_shift = 20, + .bc_mask = 0xFFF, + .drctrl_shift = 16, + .xfer_complete = (1 << 7), + .bc_overflow = 0, + .fifo_size = 64, + .ctrl_reg_addr = 4, + .stat_reg_addr = 0x18, + .period_reg_addr = 0x1C, + .test_reg_addr = 0x20, + .reset_reg_addr = 0x8, + .mode_mask = 0xF, + .spi_enable = 0x1, + .xch = (1 << 2), + .mode_shift = 4, + .master_enable = 0, + .tx_inten_dif = 0, + .rx_inten_dif = 0, + .int_status_dif = 0, + .low_pol_shift = 4, + .pha_shift = 0, + .ss_ctrl_shift = 8, + .ss_pol_shift = 12, + .max_data_rate = 0xF, + .data_mask = 0xFF, + .data_shift = 8, + .lbc = (1 << 31), + .rx_cnt_off = 8, + .rx_cnt_mask = (0x7F << 8), + .reset_start = 0, + .sclk_ctl_shift = 20, +}; + +static struct mxc_spi_unique_def spi_ver_0_7 = { + .intr_bit_shift = 8, + .cs_shift = 12, + .bc_shift = 20, + .bc_mask = 0xFFF, + .drctrl_shift = 8, + .xfer_complete = (1 << 7), + .bc_overflow = 0, + .fifo_size = 8, + .ctrl_reg_addr = 0, + .stat_reg_addr = 0x14, + .period_reg_addr = 0x18, + .test_reg_addr = 0x1C, + .reset_reg_addr = 0x0, + .mode_mask = 0x1, + .spi_enable = 0x1, + .xch = (1 << 2), + .mode_shift = 1, + .master_enable = 1 << 1, + .tx_inten_dif = 0, + .rx_inten_dif = 0, + .int_status_dif = 0, + .low_pol_shift = 4, + .pha_shift = 5, + .ss_ctrl_shift = 6, + .ss_pol_shift = 7, + .max_data_rate = 0x7, + .data_mask = 0x7, + .data_shift = 16, + .lbc = (1 << 14), + .rx_cnt_off = 4, + .rx_cnt_mask = (0xF << 4), + .reset_start = 1, +}; + +static struct mxc_spi_unique_def spi_ver_0_5 = { + .intr_bit_shift = 9, + .cs_shift = 12, + .bc_shift = 20, + .bc_mask = 0xFFF, + .drctrl_shift = 8, + .xfer_complete = (1 << 8), + .bc_overflow = (1 << 7), + .fifo_size = 8, + .ctrl_reg_addr = 0, + .stat_reg_addr = 0x14, + .period_reg_addr = 0x18, + .test_reg_addr = 0x1C, + .reset_reg_addr = 0x0, + .mode_mask = 0x1, + .spi_enable = 0x1, + .xch = (1 << 2), + .mode_shift = 1, + .master_enable = 1 << 1, + .tx_inten_dif = 0, + .rx_inten_dif = 0, + .int_status_dif = 0, + .low_pol_shift = 4, + .pha_shift = 5, + .ss_ctrl_shift = 6, + .ss_pol_shift = 7, + .max_data_rate = 0x7, + .data_mask = 0x7, + .data_shift = 16, + .lbc = (1 << 14), + .rx_cnt_off = 4, + .rx_cnt_mask = (0xF << 4), + .reset_start = 1, +}; + +static struct mxc_spi_unique_def spi_ver_0_4 = { + .intr_bit_shift = 9, + .cs_shift = 24, + .bc_shift = 8, + .bc_mask = 0x1F, + .drctrl_shift = 20, + .xfer_complete = (1 << 8), + .bc_overflow = (1 << 7), + .fifo_size = 8, + .ctrl_reg_addr = 0, + .stat_reg_addr = 0x14, + .period_reg_addr = 0x18, + .test_reg_addr = 0x1C, + .reset_reg_addr = 0x0, + .mode_mask = 0x1, + .spi_enable = 0x1, + .xch = (1 << 2), + .mode_shift = 1, + .master_enable = 1 << 1, + .tx_inten_dif = 0, + .rx_inten_dif = 0, + .int_status_dif = 0, + .low_pol_shift = 4, + .pha_shift = 5, + .ss_ctrl_shift = 6, + .ss_pol_shift = 7, + .max_data_rate = 0x7, + .data_mask = 0x7, + .data_shift = 16, + .lbc = (1 << 14), + .rx_cnt_off = 4, + .rx_cnt_mask = (0xF << 4), + .reset_start = 1, +}; + +static struct mxc_spi_unique_def spi_ver_0_0 = { + .intr_bit_shift = 18, + .cs_shift = 19, + .bc_shift = 0, + .bc_mask = 0x1F, + .drctrl_shift = 12, + .xfer_complete = (1 << 3), + .bc_overflow = (1 << 8), + .fifo_size = 8, + .ctrl_reg_addr = 0, + .stat_reg_addr = 0x0C, + .period_reg_addr = 0x14, + .test_reg_addr = 0x10, + .reset_reg_addr = 0x1C, + .mode_mask = 0x1, + .spi_enable = (1 << 10), + .xch = (1 << 9), + .mode_shift = 11, + .master_enable = 1 << 11, + .tx_inten_dif = 9, + .rx_inten_dif = 10, + .int_status_dif = 1, + .low_pol_shift = 5, + .pha_shift = 6, + .ss_ctrl_shift = 7, + .ss_pol_shift = 8, + .max_data_rate = 0x10, + .data_mask = 0x1F, + .data_shift = 14, + .lbc = (1 << 14), + .rx_cnt_off = 4, + .rx_cnt_mask = (0xF << 4), + .reset_start = 1, +}; + +extern void gpio_spi_active(int cspi_mod); +extern void gpio_spi_inactive(int cspi_mod); + +#define MXC_SPI_BUF_RX(type) \ +void mxc_spi_buf_rx_##type(struct mxc_spi *master_drv_data, u32 val)\ +{\ + type *rx = master_drv_data->transfer.rx_buf;\ + *rx++ = (type)val;\ + master_drv_data->transfer.rx_buf = rx;\ +} + +#define MXC_SPI_BUF_TX(type) \ +u32 mxc_spi_buf_tx_##type(struct mxc_spi *master_drv_data)\ +{\ + u32 val;\ + const type *tx = master_drv_data->transfer.tx_buf;\ + val = *tx++;\ + master_drv_data->transfer.tx_buf = tx;\ + return val;\ +} + +MXC_SPI_BUF_RX(u8) + MXC_SPI_BUF_TX(u8) + MXC_SPI_BUF_RX(u16) + MXC_SPI_BUF_TX(u16) + MXC_SPI_BUF_RX(u32) + MXC_SPI_BUF_TX(u32) + +/*! + * This function enables CSPI interrupt(s) + * + * @param master_data the pointer to mxc_spi structure + * @param irqs the irq(s) to set (can be a combination) + * + * @return This function returns 0 if successful, -1 otherwise. + */ +static int spi_enable_interrupt(struct mxc_spi *master_data, unsigned int irqs) +{ + if (irqs & ~((1 << master_data->spi_ver_def->intr_bit_shift) - 1)) { + return -1; + } + + __raw_writel((irqs | __raw_readl(MXC_CSPIINT + master_data->ctrl_addr)), + MXC_CSPIINT + master_data->ctrl_addr); + return 0; +} + +/*! + * This function disables CSPI interrupt(s) + * + * @param master_data the pointer to mxc_spi structure + * @param irqs the irq(s) to reset (can be a combination) + * + * @return This function returns 0 if successful, -1 otherwise. + */ +static int spi_disable_interrupt(struct mxc_spi *master_data, unsigned int irqs) +{ + if (irqs & ~((1 << master_data->spi_ver_def->intr_bit_shift) - 1)) { + return -1; + } + + __raw_writel((~irqs & + __raw_readl(MXC_CSPIINT + master_data->ctrl_addr)), + MXC_CSPIINT + master_data->ctrl_addr); + return 0; +} + +/*! + * This function sets the baud rate for the SPI module. + * + * @param master_data the pointer to mxc_spi structure + * @param baud the baud rate + * + * @return This function returns the baud rate divisor. + */ +static unsigned int spi_find_baudrate(struct mxc_spi *master_data, + unsigned int baud) +{ + unsigned int divisor; + unsigned int shift = 0; + + /* Calculate required divisor (rounded) */ + divisor = (master_data->spi_ipg_clk + baud / 2) / baud; + while (divisor >>= 1) + shift++; + + if (master_data->spi_ver_def == &spi_ver_0_0) { + shift = (shift - 1) * 2; + } else if (master_data->spi_ver_def == &spi_ver_2_3) { + shift = shift; + } else { + shift -= 2; + } + + if (shift > master_data->spi_ver_def->max_data_rate) + shift = master_data->spi_ver_def->max_data_rate; + + return shift << master_data->spi_ver_def->data_shift; +} + +/*! + * This function loads the transmit fifo. + * + * @param base the CSPI base address + * @param count number of words to put in the TxFIFO + * @param master_drv_data spi master structure + */ +static void spi_put_tx_data(void *base, unsigned int count, + struct mxc_spi *master_drv_data) +{ + unsigned int ctrl_reg; + unsigned int data; + int i = 0; + + /* Perform Tx transaction */ + for (i = 0; i < count; i++) { + data = master_drv_data->transfer.tx_get(master_drv_data); + __raw_writel(data, base + MXC_CSPITXDATA); + } + + ctrl_reg = __raw_readl(base + MXC_CSPICTRL); + + ctrl_reg |= master_drv_data->spi_ver_def->xch; + + __raw_writel(ctrl_reg, base + MXC_CSPICTRL); + + return; +} + +/*! + * This function configures the hardware CSPI for the current SPI device. + * It sets the word size, transfer mode, data rate for this device. + * + * @param spi the current SPI device + * @param is_active indicates whether to active/deactivate the current device + */ +void mxc_spi_chipselect(struct spi_device *spi, int is_active) +{ + struct mxc_spi *master_drv_data; + struct mxc_spi_xfer *ptransfer; + struct mxc_spi_unique_def *spi_ver_def; + unsigned int ctrl_reg = 0; + unsigned int config_reg = 0; + unsigned int xfer_len; + unsigned int cs_value; + + if (is_active == BITBANG_CS_INACTIVE) { + /*Need to deselect the slave */ + return; + } + + /* Get the master controller driver data from spi device's master */ + + master_drv_data = spi_master_get_devdata(spi->master); + clk_enable(master_drv_data->clk); + spi_ver_def = master_drv_data->spi_ver_def; + + xfer_len = spi->bits_per_word; + + if (spi_ver_def == &spi_ver_2_3) { + /* Control Register Settings for transfer to this slave */ + ctrl_reg = master_drv_data->spi_ver_def->spi_enable; + ctrl_reg |= + ((spi->chip_select & MXC_CSPICTRL_CSMASK) << spi_ver_def-> + cs_shift); + ctrl_reg |= + (((1 << (spi->chip_select & MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) << spi_ver_def->mode_shift); + ctrl_reg |= + spi_find_baudrate(master_drv_data, spi->max_speed_hz); + ctrl_reg |= + (((xfer_len - + 1) & spi_ver_def->bc_mask) << spi_ver_def->bc_shift); + + if (spi->mode & SPI_CPHA) + config_reg |= + (((1 << (spi->chip_select & MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) << + spi_ver_def->pha_shift); + + if ((spi->mode & SPI_CPOL)) { + config_reg |= + (((1 << (spi->chip_select & MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) << + spi_ver_def->low_pol_shift); + config_reg |= + (((1 << (spi->chip_select & MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) << + spi_ver_def->sclk_ctl_shift); + } + cs_value = (__raw_readl(MXC_CSPICONFIG + + master_drv_data->ctrl_addr) >> + spi_ver_def->ss_pol_shift) & spi_ver_def->mode_mask; + if (spi->mode & SPI_CS_HIGH) { + config_reg |= + ((((1 << (spi->chip_select & MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) | cs_value) << + spi_ver_def->ss_pol_shift); + } else + config_reg |= + ((~((1 << (spi->chip_select & + MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) & cs_value) << + spi_ver_def->ss_pol_shift); + config_reg |= + (((1 << (spi->chip_select & MXC_CSPICTRL_CSMASK)) & + spi_ver_def->mode_mask) << spi_ver_def->ss_ctrl_shift); + __raw_writel(0, master_drv_data->base + MXC_CSPICTRL); + __raw_writel(ctrl_reg, master_drv_data->base + MXC_CSPICTRL); + __raw_writel(config_reg, + MXC_CSPICONFIG + master_drv_data->ctrl_addr); + } else { + /* Control Register Settings for transfer to this slave */ + ctrl_reg = master_drv_data->spi_ver_def->spi_enable; + ctrl_reg |= + (((spi->chip_select & MXC_CSPICTRL_CSMASK) << spi_ver_def-> + cs_shift) | spi_ver_def->mode_mask << + spi_ver_def->mode_shift); + ctrl_reg |= + spi_find_baudrate(master_drv_data, spi->max_speed_hz); + ctrl_reg |= + (((xfer_len - + 1) & spi_ver_def->bc_mask) << spi_ver_def->bc_shift); + if (spi->mode & SPI_CPHA) + ctrl_reg |= + spi_ver_def->mode_mask << spi_ver_def->pha_shift; + if (spi->mode & SPI_CPOL) + ctrl_reg |= + spi_ver_def->mode_mask << spi_ver_def-> + low_pol_shift; + if (spi->mode & SPI_CS_HIGH) + ctrl_reg |= + spi_ver_def->mode_mask << spi_ver_def->ss_pol_shift; + if (spi_ver_def == &spi_ver_0_7) + ctrl_reg |= + spi_ver_def->mode_mask << spi_ver_def-> + ss_ctrl_shift; + + __raw_writel(ctrl_reg, master_drv_data->base + MXC_CSPICTRL); + } + + /* Initialize the functions for transfer */ + ptransfer = &master_drv_data->transfer; + if (xfer_len <= 8) { + ptransfer->rx_get = mxc_spi_buf_rx_u8; + ptransfer->tx_get = mxc_spi_buf_tx_u8; + } else if (xfer_len <= 16) { + ptransfer->rx_get = mxc_spi_buf_rx_u16; + ptransfer->tx_get = mxc_spi_buf_tx_u16; + } else { + ptransfer->rx_get = mxc_spi_buf_rx_u32; + ptransfer->tx_get = mxc_spi_buf_tx_u32; + } +#ifdef CONFIG_SPI_MXC_TEST_LOOPBACK + { + struct spi_chip_info *lb_chip = + (struct spi_chip_info *)spi->controller_data; + if (!lb_chip) + __raw_writel(0, master_drv_data->test_addr); + else if (lb_chip->lb_enable) + __raw_writel(spi_ver_def->lbc, + master_drv_data->test_addr); + } +#endif + clk_disable(master_drv_data->clk); + return; +} + +/*! + * This function is called when an interrupt occurs on the SPI modules. + * It is the interrupt handler for the SPI modules. + * + * @param irq the irq number + * @param dev_id the pointer on the device + * + * @return The function returns IRQ_HANDLED when handled. + */ +static irqreturn_t mxc_spi_isr(int irq, void *dev_id) +{ + struct mxc_spi *master_drv_data = dev_id; + irqreturn_t ret = IRQ_NONE; + unsigned int status; + int fifo_size; + unsigned int pass_counter; + + fifo_size = master_drv_data->spi_ver_def->fifo_size; + pass_counter = fifo_size; + + /* Read the interrupt status register to determine the source */ + status = __raw_readl(master_drv_data->stat_addr); + do { + u32 rx_tmp = + __raw_readl(master_drv_data->base + MXC_CSPIRXDATA); + + if (master_drv_data->transfer.rx_buf) + master_drv_data->transfer.rx_get(master_drv_data, + rx_tmp); + (master_drv_data->transfer.count)--; + (master_drv_data->transfer.rx_count)--; + ret = IRQ_HANDLED; + if (pass_counter-- == 0) { + break; + } + status = __raw_readl(master_drv_data->stat_addr); + } while (status & + (1 << + (MXC_CSPISTAT_RR + + master_drv_data->spi_ver_def->int_status_dif))); + + if (master_drv_data->transfer.rx_count) + return ret; + + if (master_drv_data->transfer.count) { + if (master_drv_data->transfer.tx_buf) { + u32 count = (master_drv_data->transfer.count > + fifo_size) ? fifo_size : + master_drv_data->transfer.count; + master_drv_data->transfer.rx_count = count; + spi_put_tx_data(master_drv_data->base, count, + master_drv_data); + } + } else { + complete(&master_drv_data->xfer_done); + } + + return ret; +} + +/*! + * This function initialize the current SPI device. + * + * @param spi the current SPI device. + * + */ +int mxc_spi_setup(struct spi_device *spi) +{ + if (spi->max_speed_hz < 0) { + return -EINVAL; + } + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + pr_debug("%s: mode %d, %u bpw, %d hz\n", __FUNCTION__, + spi->mode, spi->bits_per_word, spi->max_speed_hz); + + return 0; +} + +static int mxc_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) +{ + return 0; +} + +/*! + * This function is called when the data has to transfer from/to the + * current SPI device in poll mode + * + * @param spi the current spi device + * @param t the transfer request - read/write buffer pairs + * + * @return Returns 0 on success. + */ +int mxc_spi_poll_transfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct mxc_spi *master_drv_data = NULL; + int count, i; + volatile unsigned int status; + u32 rx_tmp; + u32 fifo_size; + int chipselect_status; + + mxc_spi_chipselect(spi, BITBANG_CS_ACTIVE); + + /* Get the master controller driver data from spi device's master */ + master_drv_data = spi_master_get_devdata(spi->master); + + chipselect_status = __raw_readl(MXC_CSPICONFIG + + master_drv_data->ctrl_addr); + chipselect_status >>= master_drv_data->spi_ver_def->ss_pol_shift & + master_drv_data->spi_ver_def->mode_mask; + if (master_drv_data->chipselect_active) + master_drv_data->chipselect_active(spi->master->bus_num, + chipselect_status, + (spi->chip_select & + MXC_CSPICTRL_CSMASK) + 1); + + clk_enable(master_drv_data->clk); + + /* Modify the Tx, Rx, Count */ + master_drv_data->transfer.tx_buf = t->tx_buf; + master_drv_data->transfer.rx_buf = t->rx_buf; + master_drv_data->transfer.count = t->len; + fifo_size = master_drv_data->spi_ver_def->fifo_size; + + count = (t->len > fifo_size) ? fifo_size : t->len; + spi_put_tx_data(master_drv_data->base, count, master_drv_data); + + while ((((status = __raw_readl(master_drv_data->test_addr)) & + master_drv_data->spi_ver_def->rx_cnt_mask) >> master_drv_data-> + spi_ver_def->rx_cnt_off) != count) + ; + + for (i = 0; i < count; i++) { + rx_tmp = __raw_readl(master_drv_data->base + MXC_CSPIRXDATA); + master_drv_data->transfer.rx_get(master_drv_data, rx_tmp); + } + + clk_disable(master_drv_data->clk); + if (master_drv_data->chipselect_inactive) + master_drv_data->chipselect_inactive(spi->master->bus_num, + chipselect_status, + (spi->chip_select & + MXC_CSPICTRL_CSMASK) + 1); + return 0; +} + +/*! + * This function is called when the data has to transfer from/to the + * current SPI device. It enables the Rx interrupt, initiates the transfer. + * When Rx interrupt occurs, the completion flag is set. It then disables + * the Rx interrupt. + * + * @param spi the current spi device + * @param t the transfer request - read/write buffer pairs + * + * @return Returns 0 on success -1 on failure. + */ +int mxc_spi_transfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct mxc_spi *master_drv_data = NULL; + int count; + int chipselect_status; + u32 fifo_size; + + /* Get the master controller driver data from spi device's master */ + + master_drv_data = spi_master_get_devdata(spi->master); + + chipselect_status = __raw_readl(MXC_CSPICONFIG + + master_drv_data->ctrl_addr); + chipselect_status >>= master_drv_data->spi_ver_def->ss_pol_shift & + master_drv_data->spi_ver_def->mode_mask; + if (master_drv_data->chipselect_active) + master_drv_data->chipselect_active(spi->master->bus_num, + chipselect_status, + (spi->chip_select & + MXC_CSPICTRL_CSMASK) + 1); + + clk_enable(master_drv_data->clk); + /* Modify the Tx, Rx, Count */ + master_drv_data->transfer.tx_buf = t->tx_buf; + master_drv_data->transfer.rx_buf = t->rx_buf; + master_drv_data->transfer.count = t->len; + fifo_size = master_drv_data->spi_ver_def->fifo_size; + INIT_COMPLETION(master_drv_data->xfer_done); + + /* Enable the Rx Interrupts */ + + spi_enable_interrupt(master_drv_data, + 1 << (MXC_CSPIINT_RREN_SHIFT + + master_drv_data->spi_ver_def->rx_inten_dif)); + count = (t->len > fifo_size) ? fifo_size : t->len; + + /* Perform Tx transaction */ + master_drv_data->transfer.rx_count = count; + spi_put_tx_data(master_drv_data->base, count, master_drv_data); + + /* Wait for transfer completion */ + wait_for_completion(&master_drv_data->xfer_done); + + /* Disable the Rx Interrupts */ + + spi_disable_interrupt(master_drv_data, + 1 << (MXC_CSPIINT_RREN_SHIFT + + master_drv_data->spi_ver_def-> + rx_inten_dif)); + + clk_disable(master_drv_data->clk); + if (master_drv_data->chipselect_inactive) + master_drv_data->chipselect_inactive(spi->master->bus_num, + chipselect_status, + (spi->chip_select & + MXC_CSPICTRL_CSMASK) + 1); + return t->len - master_drv_data->transfer.count; +} + +/*! + * This function releases the current SPI device's resources. + * + * @param spi the current SPI device. + * + */ +void mxc_spi_cleanup(struct spi_device *spi) +{ +} + +/*! + * This function is called during the driver binding process. Based on the CSPI + * hardware module that is being probed this function adds the appropriate SPI module + * structure in the SPI core driver. + * + * @param pdev the device structure used to store device specific + * information that is used by the suspend, resume and remove + * functions. + * + * @return The function returns 0 on successful registration and initialization + * of CSPI module. Otherwise returns specific error code. + */ +static int mxc_spi_probe(struct platform_device *pdev) +{ + struct mxc_spi_master *mxc_platform_info; + struct spi_master *master; + struct mxc_spi *master_drv_data = NULL; + unsigned int spi_ver; + int ret = -ENODEV; + + /* Get the platform specific data for this master device */ + + mxc_platform_info = (struct mxc_spi_master *)pdev->dev.platform_data; + if (!mxc_platform_info) { + dev_err(&pdev->dev, "can't get the platform data for CSPI\n"); + return -EINVAL; + } + + /* Allocate SPI master controller */ + + master = spi_alloc_master(&pdev->dev, sizeof(struct mxc_spi)); + if (!master) { + dev_err(&pdev->dev, "can't alloc for spi_master\n"); + return -ENOMEM; + } + + /* Set this device's driver data to master */ + + platform_set_drvdata(pdev, master); + + /* Set this master's data from platform_info */ + + master->bus_num = pdev->id + 1; + master->num_chipselect = mxc_platform_info->maxchipselect; + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; +#ifdef CONFIG_SPI_MXC_TEST_LOOPBACK + master->num_chipselect += 1; +#endif + /* Set the master controller driver data for this master */ + + master_drv_data = spi_master_get_devdata(master); + master_drv_data->mxc_bitbang.master = spi_master_get(master); + if (mxc_platform_info->chipselect_active) + master_drv_data->chipselect_active = + mxc_platform_info->chipselect_active; + if (mxc_platform_info->chipselect_inactive) + master_drv_data->chipselect_inactive = + mxc_platform_info->chipselect_inactive; + + /* Identify SPI version */ + + spi_ver = mxc_platform_info->spi_version; + if (spi_ver == 7) { + master_drv_data->spi_ver_def = &spi_ver_0_7; + } else if (spi_ver == 5) { + master_drv_data->spi_ver_def = &spi_ver_0_5; + } else if (spi_ver == 4) { + master_drv_data->spi_ver_def = &spi_ver_0_4; + } else if (spi_ver == 0) { + master_drv_data->spi_ver_def = &spi_ver_0_0; + } else if (spi_ver == 23) { + master_drv_data->spi_ver_def = &spi_ver_2_3; + } + + dev_dbg(&pdev->dev, "SPI_REV 0.%d\n", spi_ver); + + /* Set the master bitbang data */ + + master_drv_data->mxc_bitbang.chipselect = mxc_spi_chipselect; + master_drv_data->mxc_bitbang.txrx_bufs = mxc_spi_transfer; + master_drv_data->mxc_bitbang.master->setup = mxc_spi_setup; + master_drv_data->mxc_bitbang.master->cleanup = mxc_spi_cleanup; + master_drv_data->mxc_bitbang.setup_transfer = mxc_spi_setup_transfer; + + /* Initialize the completion object */ + + init_completion(&master_drv_data->xfer_done); + + /* Set the master controller register addresses and irqs */ + + master_drv_data->res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!master_drv_data->res) { + dev_err(&pdev->dev, "can't get platform resource for CSPI%d\n", + master->bus_num); + ret = -ENOMEM; + goto err; + } + + if (!request_mem_region(master_drv_data->res->start, + master_drv_data->res->end - + master_drv_data->res->start + 1, pdev->name)) { + dev_err(&pdev->dev, "request_mem_region failed for CSPI%d\n", + master->bus_num); + ret = -ENOMEM; + goto err; + } + + master_drv_data->base = ioremap(master_drv_data->res->start, + master_drv_data->res->end - master_drv_data->res->start + 1); + if (!master_drv_data->base) { + dev_err(&pdev->dev, "invalid base address for CSPI%d\n", + master->bus_num); + ret = -EINVAL; + goto err1; + } + + master_drv_data->irq = platform_get_irq(pdev, 0); + if (master_drv_data->irq < 0) { + dev_err(&pdev->dev, "can't get IRQ for CSPI%d\n", + master->bus_num); + ret = -EINVAL; + goto err1; + } + + /* Register for SPI Interrupt */ + + ret = request_irq(master_drv_data->irq, mxc_spi_isr, + 0, "CSPI_IRQ", master_drv_data); + if (ret != 0) { + dev_err(&pdev->dev, "request_irq failed for CSPI%d\n", + master->bus_num); + goto err1; + } + + /* Setup any GPIO active */ + + gpio_spi_active(master->bus_num - 1); + + /* Enable the CSPI Clock, CSPI Module, set as a master */ + + master_drv_data->ctrl_addr = + master_drv_data->base + master_drv_data->spi_ver_def->ctrl_reg_addr; + master_drv_data->stat_addr = + master_drv_data->base + master_drv_data->spi_ver_def->stat_reg_addr; + master_drv_data->period_addr = + master_drv_data->base + + master_drv_data->spi_ver_def->period_reg_addr; + master_drv_data->test_addr = + master_drv_data->base + master_drv_data->spi_ver_def->test_reg_addr; + master_drv_data->reset_addr = + master_drv_data->base + + master_drv_data->spi_ver_def->reset_reg_addr; + + master_drv_data->clk = clk_get(&pdev->dev, "cspi_clk"); + clk_enable(master_drv_data->clk); + master_drv_data->spi_ipg_clk = clk_get_rate(master_drv_data->clk); + + __raw_writel(master_drv_data->spi_ver_def->reset_start, + master_drv_data->reset_addr); + udelay(1); + __raw_writel((master_drv_data->spi_ver_def->spi_enable + + master_drv_data->spi_ver_def->master_enable), + master_drv_data->base + MXC_CSPICTRL); + __raw_writel(MXC_CSPIPERIOD_32KHZ, master_drv_data->period_addr); + __raw_writel(0, MXC_CSPIINT + master_drv_data->ctrl_addr); + + /* Start the SPI Master Controller driver */ + + ret = spi_bitbang_start(&master_drv_data->mxc_bitbang); + + if (ret != 0) + goto err2; + + printk(KERN_INFO "CSPI: %s-%d probed\n", pdev->name, pdev->id); + +#ifdef CONFIG_SPI_MXC_TEST_LOOPBACK + { + int i; + struct spi_board_info *bi = &loopback_info[0]; + for (i = 0; i < ARRAY_SIZE(loopback_info); i++, bi++) { + if (bi->bus_num != master->bus_num) + continue; + + dev_info(&pdev->dev, + "registering loopback device '%s'\n", + bi->modalias); + + spi_new_device(master, bi); + } + } +#endif + clk_disable(master_drv_data->clk); + return ret; + + err2: + gpio_spi_inactive(master->bus_num - 1); + clk_disable(master_drv_data->clk); + clk_put(master_drv_data->clk); + free_irq(master_drv_data->irq, master_drv_data); + err1: + iounmap(master_drv_data->base); + release_mem_region(pdev->resource[0].start, + pdev->resource[0].end - pdev->resource[0].start + 1); + err: + spi_master_put(master); + kfree(master); + platform_set_drvdata(pdev, NULL); + return ret; +} + +/*! + * Dissociates the driver from the SPI master controller. Disables the CSPI module. + * It handles the release of SPI resources like IRQ, memory,..etc. + * + * @param pdev the device structure used to give information on which SPI + * to remove + * + * @return The function always returns 0. + */ +static int mxc_spi_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + + if (master) { + struct mxc_spi *master_drv_data = + spi_master_get_devdata(master); + + gpio_spi_inactive(master->bus_num - 1); + + /* Disable the CSPI module */ + clk_enable(master_drv_data->clk); + __raw_writel(MXC_CSPICTRL_DISABLE, + master_drv_data->base + MXC_CSPICTRL); + clk_disable(master_drv_data->clk); + /* Unregister for SPI Interrupt */ + + free_irq(master_drv_data->irq, master_drv_data); + + iounmap(master_drv_data->base); + release_mem_region(master_drv_data->res->start, + master_drv_data->res->end - + master_drv_data->res->start + 1); + + /* Stop the SPI Master Controller driver */ + + spi_bitbang_stop(&master_drv_data->mxc_bitbang); + + spi_master_put(master); + } + + printk(KERN_INFO "CSPI: %s-%d removed\n", pdev->name, pdev->id); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +#ifdef CONFIG_PM +static int spi_bitbang_suspend(struct spi_bitbang *bitbang) +{ + unsigned long flags; + unsigned limit = 500; + + spin_lock_irqsave(&bitbang->lock, flags); + while (!list_empty(&bitbang->queue) && limit--) { + spin_unlock_irqrestore(&bitbang->lock, flags); + + dev_dbg(&bitbang->master->dev, "wait for queue\n"); + msleep(10); + + spin_lock_irqsave(&bitbang->lock, flags); + } + if (!list_empty(&bitbang->queue)) { + dev_err(&bitbang->master->dev, "queue didn't empty\n"); + spin_unlock_irqrestore(&bitbang->lock, flags); + return -EBUSY; + } + spin_unlock_irqrestore(&bitbang->lock, flags); + + return 0; +} + +static void spi_bitbang_resume(struct spi_bitbang *bitbang) +{ + spin_lock_init(&bitbang->lock); + INIT_LIST_HEAD(&bitbang->queue); + + bitbang->busy = 0; +} + +/*! + * This function puts the SPI master controller in low-power mode/state. + * + * @param pdev the device structure used to give information on which SDHC + * to suspend + * @param state the power state the device is entering + * + * @return The function always returns 0. + */ +static int mxc_spi_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct mxc_spi *master_drv_data = spi_master_get_devdata(master); + int ret = 0; + + spi_bitbang_suspend(&master_drv_data->mxc_bitbang); + clk_enable(master_drv_data->clk); + __raw_writel(MXC_CSPICTRL_DISABLE, + master_drv_data->base + MXC_CSPICTRL); + clk_disable(master_drv_data->clk); + gpio_spi_inactive(master->bus_num - 1); + + return ret; +} + +/*! + * This function brings the SPI master controller back from low-power state. + * + * @param pdev the device structure used to give information on which SDHC + * to resume + * + * @return The function always returns 0. + */ +static int mxc_spi_resume(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct mxc_spi *master_drv_data = spi_master_get_devdata(master); + + gpio_spi_active(master->bus_num - 1); + + spi_bitbang_resume(&master_drv_data->mxc_bitbang); + clk_enable(master_drv_data->clk); + __raw_writel((master_drv_data->spi_ver_def->spi_enable + + master_drv_data->spi_ver_def->master_enable), + master_drv_data->base + MXC_CSPICTRL); + clk_disable(master_drv_data->clk); + + return 0; +} +#else +#define mxc_spi_suspend NULL +#define mxc_spi_resume NULL +#endif /* CONFIG_PM */ + +/*! + * This structure contains pointers to the power management callback functions. + */ +static struct platform_driver mxc_spi_driver = { + .driver = { + .name = "mxc_spi", + .owner = THIS_MODULE, + }, + .probe = mxc_spi_probe, + .remove = mxc_spi_remove, + .suspend = mxc_spi_suspend, + .resume = mxc_spi_resume, +}; + +/*! + * This function implements the init function of the SPI device. + * It is called when the module is loaded. It enables the required + * clocks to CSPI module(if any) and activates necessary GPIO pins. + * + * @return This function returns 0. + */ +static int __init mxc_spi_init(void) +{ + pr_debug("Registering the SPI Controller Driver\n"); + return platform_driver_register(&mxc_spi_driver); +} + +/*! + * This function implements the exit function of the SPI device. + * It is called when the module is unloaded. It deactivates the + * the GPIO pin associated with CSPI hardware modules. + * + */ +static void __exit mxc_spi_exit(void) +{ + pr_debug("Unregistering the SPI Controller Driver\n"); + platform_driver_unregister(&mxc_spi_driver); +} + +subsys_initcall(mxc_spi_init); +module_exit(mxc_spi_exit); + +MODULE_DESCRIPTION("SPI Master Controller driver"); +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_LICENSE("GPL"); |