/* * Designware SPI core controller driver (refer pxa2xx_spi.c) * * Copyright (c) 2009, Intel Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ #include #include #include #include #include #include #include #include #include "spi-dw.h" #ifdef CONFIG_DEBUG_FS #include #endif #define START_STATE ((void *)0) #define RUNNING_STATE ((void *)1) #define DONE_STATE ((void *)2) #define ERROR_STATE ((void *)-1) /* Slave spi_dev related */ struct chip_data { u16 cr0; u8 cs; /* chip select pin */ u8 n_bytes; /* current is a 1/2/4 byte op */ u8 tmode; /* TR/TO/RO/EEPROM */ u8 type; /* SPI/SSP/MicroWire */ u8 poll_mode; /* 1 means use poll mode */ u32 dma_width; u32 rx_threshold; u32 tx_threshold; u8 enable_dma; u8 bits_per_word; u16 clk_div; /* baud rate divider */ u32 speed_hz; /* baud rate */ void (*cs_control)(u32 command); }; #ifdef CONFIG_DEBUG_FS #define SPI_REGS_BUFSIZE 1024 static ssize_t dw_spi_show_regs(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { struct dw_spi *dws = file->private_data; char *buf; u32 len = 0; ssize_t ret; buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL); if (!buf) return 0; len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "%s registers:\n", dev_name(&dws->master->dev)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "=================================\n"); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "CTRL0: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL0)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "CTRL1: \t\t0x%08x\n", dw_readl(dws, DW_SPI_CTRL1)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "SSIENR: \t0x%08x\n", dw_readl(dws, DW_SPI_SSIENR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "SER: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SER)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "BAUDR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_BAUDR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "TXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_TXFLTR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "RXFTLR: \t0x%08x\n", dw_readl(dws, DW_SPI_RXFLTR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "TXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_TXFLR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "RXFLR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_RXFLR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "SR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_SR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "IMR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_IMR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "ISR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_ISR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "DMACR: \t\t0x%08x\n", dw_readl(dws, DW_SPI_DMACR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "DMATDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMATDLR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "DMARDLR: \t0x%08x\n", dw_readl(dws, DW_SPI_DMARDLR)); len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, "=================================\n"); ret = simple_read_from_buffer(user_buf, count, ppos, buf, len); kfree(buf); return ret; } static const struct file_operations dw_spi_regs_ops = { .owner = THIS_MODULE, .open = simple_open, .read = dw_spi_show_regs, .llseek = default_llseek, }; static int dw_spi_debugfs_init(struct dw_spi *dws) { dws->debugfs = debugfs_create_dir("dw_spi", NULL); if (!dws->debugfs) return -ENOMEM; debugfs_create_file("registers", S_IFREG | S_IRUGO, dws->debugfs, (void *)dws, &dw_spi_regs_ops); return 0; } static void dw_spi_debugfs_remove(struct dw_spi *dws) { debugfs_remove_recursive(dws->debugfs); } #else static inline int dw_spi_debugfs_init(struct dw_spi *dws) { return 0; } static inline void dw_spi_debugfs_remove(struct dw_spi *dws) { } #endif /* CONFIG_DEBUG_FS */ /* Return the max entries we can fill into tx fifo */ static inline u32 tx_max(struct dw_spi *dws) { u32 tx_left, tx_room, rxtx_gap; tx_left = (dws->tx_end - dws->tx) / dws->n_bytes; tx_room = dws->fifo_len - dw_readw(dws, DW_SPI_TXFLR); /* * Another concern is about the tx/rx mismatch, we * though to use (dws->fifo_len - rxflr - txflr) as * one maximum value for tx, but it doesn't cover the * data which is out of tx/rx fifo and inside the * shift registers. So a control from sw point of * view is taken. */ rxtx_gap = ((dws->rx_end - dws->rx) - (dws->tx_end - dws->tx)) / dws->n_bytes; return min3(tx_left, tx_room, (u32) (dws->fifo_len - rxtx_gap)); } /* Return the max entries we should read out of rx fifo */ static inline u32 rx_max(struct dw_spi *dws) { u32 rx_left = (dws->rx_end - dws->rx) / dws->n_bytes; return min_t(u32, rx_left, dw_readw(dws, DW_SPI_RXFLR)); } static void dw_writer(struct dw_spi *dws) { u32 max = tx_max(dws); u16 txw = 0; while (max--) { /* Set the tx word if the transfer's original "tx" is not null */ if (dws->tx_end - dws->len) { if (dws->n_bytes == 1) txw = *(u8 *)(dws->tx); else txw = *(u16 *)(dws->tx); } dw_writew(dws, DW_SPI_DR, txw); dws->tx += dws->n_bytes; } } static void dw_reader(struct dw_spi *dws) { u32 max = rx_max(dws); u16 rxw; while (max--) { rxw = dw_readw(dws, DW_SPI_DR); /* Care rx only if the transfer's original "rx" is not null */ if (dws->rx_end - dws->len) { if (dws->n_bytes == 1) *(u8 *)(dws->rx) = rxw; else *(u16 *)(dws->rx) = rxw; } dws->rx += dws->n_bytes; } } static void *next_transfer(struct dw_spi *dws) { struct spi_message *msg = dws->cur_msg; struct spi_transfer *trans = dws->cur_transfer; /* Move to next transfer */ if (trans->transfer_list.next != &msg->transfers) { dws->cur_transfer = list_entry(trans->transfer_list.next, struct spi_transfer, transfer_list); return RUNNING_STATE; } return DONE_STATE; } /* * Note: first step is the protocol driver prepares * a dma-capable memory, and this func just need translate * the virt addr to physical */ static int map_dma_buffers(struct dw_spi *dws) { if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited || !dws->cur_chip->enable_dma || !dws->dma_ops) return 0; if (dws->cur_transfer->tx_dma) dws->tx_dma = dws->cur_transfer->tx_dma; if (dws->cur_transfer->rx_dma) dws->rx_dma = dws->cur_transfer->rx_dma; return 1; } /* Caller already set message->status; dma and pio irqs are blocked */ static void giveback(struct dw_spi *dws) { struct spi_transfer *last_transfer; struct spi_message *msg; msg = dws->cur_msg; dws->cur_msg = NULL; dws->cur_transfer = NULL; dws->prev_chip = dws->cur_chip; dws->cur_chip = NULL; dws->dma_mapped = 0; last_transfer = list_last_entry(&msg->transfers, struct spi_transfer, transfer_list); if (!last_transfer->cs_change) spi_chip_sel(dws, msg->spi, 0); spi_finalize_current_message(dws->master); } static void int_error_stop(struct dw_spi *dws, const char *msg) { spi_reset_chip(dws); dev_err(&dws->master->dev, "%s\n", msg); dws->cur_msg->state = ERROR_STATE; tasklet_schedule(&dws->pump_transfers); } void dw_spi_xfer_done(struct dw_spi *dws) { /* Update total byte transferred return count actual bytes read */ dws->cur_msg->actual_length += dws->len; /* Move to next transfer */ dws->cur_msg->state = next_transfer(dws); /* Handle end of message */ if (dws->cur_msg->state == DONE_STATE) { dws->cur_msg->status = 0; giveback(dws); } else tasklet_schedule(&dws->pump_transfers); } EXPORT_SYMBOL_GPL(dw_spi_xfer_done); static irqreturn_t interrupt_transfer(struct dw_spi *dws) { u16 irq_status = dw_readw(dws, DW_SPI_ISR); /* Error handling */ if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) { dw_readw(dws, DW_SPI_TXOICR); dw_readw(dws, DW_SPI_RXOICR); dw_readw(dws, DW_SPI_RXUICR); int_error_stop(dws, "interrupt_transfer: fifo overrun/underrun"); return IRQ_HANDLED; } dw_reader(dws); if (dws->rx_end == dws->rx) { spi_mask_intr(dws, SPI_INT_TXEI); dw_spi_xfer_done(dws); return IRQ_HANDLED; } if (irq_status & SPI_INT_TXEI) { spi_mask_intr(dws, SPI_INT_TXEI); dw_writer(dws); /* Enable TX irq always, it will be disabled when RX finished */ spi_umask_intr(dws, SPI_INT_TXEI); } return IRQ_HANDLED; } static irqreturn_t dw_spi_irq(int irq, void *dev_id) { struct dw_spi *dws = dev_id; u16 irq_status = dw_readw(dws, DW_SPI_ISR) & 0x3f; if (!irq_status) return IRQ_NONE; if (!dws->cur_msg) { spi_mask_intr(dws, SPI_INT_TXEI); return IRQ_HANDLED; } return dws->transfer_handler(dws); } /* Must be called inside pump_transfers() */ static void poll_transfer(struct dw_spi *dws) { do { dw_writer(dws); dw_reader(dws); cpu_relax(); } while (dws->rx_end > dws->rx); dw_spi_xfer_done(dws); } static void pump_transfers(unsigned long data) { struct dw_spi *dws = (struct dw_spi *)data; struct spi_message *message = NULL; struct spi_transfer *transfer = NULL; struct spi_transfer *previous = NULL; struct spi_device *spi = NULL; struct chip_data *chip = NULL; u8 bits = 0; u8 imask = 0; u8 cs_change = 0; u16 txlevel = 0; u16 clk_div = 0; u32 speed = 0; u32 cr0 = 0; /* Get current state information */ message = dws->cur_msg; transfer = dws->cur_transfer; chip = dws->cur_chip; spi = message->spi; if (message->state == ERROR_STATE) { message->status = -EIO; goto early_exit; } /* Handle end of message */ if (message->state == DONE_STATE) { message->status = 0; goto early_exit; } /* Delay if requested at end of transfer */ if (message->state == RUNNING_STATE) { previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); if (previous->delay_usecs) udelay(previous->delay_usecs); } dws->n_bytes = chip->n_bytes; dws->dma_width = chip->dma_width; dws->cs_control = chip->cs_control; dws->rx_dma = transfer->rx_dma; dws->tx_dma = transfer->tx_dma; dws->tx = (void *)transfer->tx_buf; dws->tx_end = dws->tx + transfer->len; dws->rx = transfer->rx_buf; dws->rx_end = dws->rx + transfer->len; dws->len = dws->cur_transfer->len; if (chip != dws->prev_chip) cs_change = 1; cr0 = chip->cr0; /* Handle per transfer options for bpw and speed */ if (transfer->speed_hz) { speed = chip->speed_hz; if ((transfer->speed_hz != speed) || !chip->clk_div) { speed = transfer->speed_hz; /* clk_div doesn't support odd number */ clk_div = (dws->max_freq / speed + 1) & 0xfffe; chip->speed_hz = speed; chip->clk_div = clk_div; } } if (transfer->bits_per_word) { bits = transfer->bits_per_word; dws->n_bytes = dws->dma_width = bits >> 3; cr0 = (bits - 1) | (chip->type << SPI_FRF_OFFSET) | (spi->mode << SPI_MODE_OFFSET) | (chip->tmode << SPI_TMOD_OFFSET); } message->state = RUNNING_STATE; /* * Adjust transfer mode if necessary. Requires platform dependent * chipselect mechanism. */ if (dws->cs_control) { if (dws->rx && dws->tx) chip->tmode = SPI_TMOD_TR; else if (dws->rx) chip->tmode = SPI_TMOD_RO; else chip->tmode = SPI_TMOD_TO; cr0 &= ~SPI_TMOD_MASK; cr0 |= (chip->tmode << SPI_TMOD_OFFSET); } /* Check if current transfer is a DMA transaction */ dws->dma_mapped = map_dma_buffers(dws); /* * Interrupt mode * we only need set the TXEI IRQ, as TX/RX always happen syncronizely */ if (!dws->dma_mapped && !chip->poll_mode) { txlevel = min_t(u16, dws->fifo_len / 2, dws->len / dws->n_bytes); imask |= SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI; dws->transfer_handler = interrupt_transfer; } /* * Reprogram registers only if * 1. chip select changes * 2. clk_div is changed * 3. control value changes */ if (dw_readw(dws, DW_SPI_CTRL0) != cr0 || cs_change || clk_div || imask) { spi_enable_chip(dws, 0); dw_writew(dws, DW_SPI_CTRL0, cr0); spi_set_clk(dws, chip->clk_div); spi_chip_sel(dws, spi, 1); /* Set the interrupt mask, for poll mode just disable all int */ spi_mask_intr(dws, 0xff); if (imask) spi_umask_intr(dws, imask); if (txlevel) dw_writew(dws, DW_SPI_TXFLTR, txlevel); spi_enable_chip(dws, 1); } if (cs_change) dws->prev_chip = chip; if (dws->dma_mapped) dws->dma_ops->dma_transfer(dws, cs_change); if (chip->poll_mode) poll_transfer(dws); return; early_exit: giveback(dws); } static int dw_spi_transfer_one_message(struct spi_master *master, struct spi_message *msg) { struct dw_spi *dws = spi_master_get_devdata(master); dws->cur_msg = msg; /* Initial message state */ dws->cur_msg->state = START_STATE; dws->cur_transfer = list_entry(dws->cur_msg->transfers.next, struct spi_transfer, transfer_list); dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi); /* Launch transfers */ tasklet_schedule(&dws->pump_transfers); return 0; } /* This may be called twice for each spi dev */ static int dw_spi_setup(struct spi_device *spi) { struct dw_spi_chip *chip_info = NULL; struct chip_data *chip; int ret; /* Only alloc on first setup */ chip = spi_get_ctldata(spi); if (!chip) { chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) return -ENOMEM; spi_set_ctldata(spi, chip); } /* * Protocol drivers may change the chip settings, so... * if chip_info exists, use it */ chip_info = spi->controller_data; /* chip_info doesn't always exist */ if (chip_info) { if (chip_info->cs_control) chip->cs_control = chip_info->cs_control; chip->poll_mode = chip_info->poll_mode; chip->type = chip_info->type; chip->rx_threshold = 0; chip->tx_threshold = 0; chip->enable_dma = chip_info->enable_dma; } if (spi->bits_per_word == 8) { chip->n_bytes = 1; chip->dma_width = 1; } else if (spi->bits_per_word == 16) { chip->n_bytes = 2; chip->dma_width = 2; } chip->bits_per_word = spi->bits_per_word; if (!spi->max_speed_hz) { dev_err(&spi->dev, "No max speed HZ parameter\n"); return -EINVAL; } chip->tmode = 0; /* Tx & Rx */ /* Default SPI mode is SCPOL = 0, SCPH = 0 */ chip->cr0 = (chip->bits_per_word - 1) | (chip->type << SPI_FRF_OFFSET) | (spi->mode << SPI_MODE_OFFSET) | (chip->tmode << SPI_TMOD_OFFSET); if (spi->mode & SPI_LOOP) chip->cr0 |= 1 << SPI_SRL_OFFSET; if (gpio_is_valid(spi->cs_gpio)) { ret = gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); if (ret) return ret; } return 0; } static void dw_spi_cleanup(struct spi_device *spi) { struct chip_data *chip = spi_get_ctldata(spi); kfree(chip); spi_set_ctldata(spi, NULL); } /* Restart the controller, disable all interrupts, clean rx fifo */ static void spi_hw_init(struct device *dev, struct dw_spi *dws) { spi_reset_chip(dws); /* * Try to detect the FIFO depth if not set by interface driver, * the depth could be from 2 to 256 from HW spec */ if (!dws->fifo_len) { u32 fifo; for (fifo = 2; fifo <= 256; fifo++) { dw_writew(dws, DW_SPI_TXFLTR, fifo); if (fifo != dw_readw(dws, DW_SPI_TXFLTR)) break; } dw_writew(dws, DW_SPI_TXFLTR, 0); dws->fifo_len = (fifo == 2) ? 0 : fifo - 1; dev_dbg(dev, "Detected FIFO size: %u bytes\n", dws->fifo_len); } } int dw_spi_add_host(struct device *dev, struct dw_spi *dws) { struct spi_master *master; int ret; BUG_ON(dws == NULL); master = spi_alloc_master(dev, 0); if (!master) return -ENOMEM; dws->master = master; dws->type = SSI_MOTO_SPI; dws->prev_chip = NULL; dws->dma_inited = 0; dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60); snprintf(dws->name, sizeof(dws->name), "dw_spi%d", dws->bus_num); ret = devm_request_irq(dev, dws->irq, dw_spi_irq, IRQF_SHARED, dws->name, dws); if (ret < 0) { dev_err(&master->dev, "can not get IRQ\n"); goto err_free_master; } master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP; master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16); master->bus_num = dws->bus_num; master->num_chipselect = dws->num_cs; master->setup = dw_spi_setup; master->cleanup = dw_spi_cleanup; master->transfer_one_message = dw_spi_transfer_one_message; master->max_speed_hz = dws->max_freq; master->dev.of_node = dev->of_node; /* Basic HW init */ spi_hw_init(dev, dws); if (dws->dma_ops && dws->dma_ops->dma_init) { ret = dws->dma_ops->dma_init(dws); if (ret) { dev_warn(dev, "DMA init failed\n"); dws->dma_inited = 0; } } tasklet_init(&dws->pump_transfers, pump_transfers, (unsigned long)dws); spi_master_set_devdata(master, dws); ret = devm_spi_register_master(dev, master); if (ret) { dev_err(&master->dev, "problem registering spi master\n"); goto err_dma_exit; } dw_spi_debugfs_init(dws); return 0; err_dma_exit: if (dws->dma_ops && dws->dma_ops->dma_exit) dws->dma_ops->dma_exit(dws); spi_enable_chip(dws, 0); err_free_master: spi_master_put(master); return ret; } EXPORT_SYMBOL_GPL(dw_spi_add_host); void dw_spi_remove_host(struct dw_spi *dws) { if (!dws) return; dw_spi_debugfs_remove(dws); if (dws->dma_ops && dws->dma_ops->dma_exit) dws->dma_ops->dma_exit(dws); spi_enable_chip(dws, 0); /* Disable clk */ spi_set_clk(dws, 0); } EXPORT_SYMBOL_GPL(dw_spi_remove_host); int dw_spi_suspend_host(struct dw_spi *dws) { int ret = 0; ret = spi_master_suspend(dws->master); if (ret) return ret; spi_enable_chip(dws, 0); spi_set_clk(dws, 0); return ret; } EXPORT_SYMBOL_GPL(dw_spi_suspend_host); int dw_spi_resume_host(struct dw_spi *dws) { int ret; spi_hw_init(&dws->master->dev, dws); ret = spi_master_resume(dws->master); if (ret) dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret); return ret; } EXPORT_SYMBOL_GPL(dw_spi_resume_host); MODULE_AUTHOR("Feng Tang "); MODULE_DESCRIPTION("Driver for DesignWare SPI controller core"); MODULE_LICENSE("GPL v2");