diff options
Diffstat (limited to 'drivers/spi/orion_spi.c')
| -rw-r--r-- | drivers/spi/orion_spi.c | 573 |
1 files changed, 0 insertions, 573 deletions
diff --git a/drivers/spi/orion_spi.c b/drivers/spi/orion_spi.c deleted file mode 100644 index 0b677dc041ad..000000000000 --- a/drivers/spi/orion_spi.c +++ /dev/null @@ -1,573 +0,0 @@ -/* - * orion_spi.c -- Marvell Orion SPI controller driver - * - * Author: Shadi Ammouri <shadi@marvell.com> - * Copyright (C) 2007-2008 Marvell Ltd. - * - * This program 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. - */ - -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/platform_device.h> -#include <linux/err.h> -#include <linux/io.h> -#include <linux/spi/spi.h> -#include <linux/spi/orion_spi.h> -#include <asm/unaligned.h> - -#define DRIVER_NAME "orion_spi" - -#define ORION_NUM_CHIPSELECTS 1 /* only one slave is supported*/ -#define ORION_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */ - -#define ORION_SPI_IF_CTRL_REG 0x00 -#define ORION_SPI_IF_CONFIG_REG 0x04 -#define ORION_SPI_DATA_OUT_REG 0x08 -#define ORION_SPI_DATA_IN_REG 0x0c -#define ORION_SPI_INT_CAUSE_REG 0x10 - -#define ORION_SPI_IF_8_16_BIT_MODE (1 << 5) -#define ORION_SPI_CLK_PRESCALE_MASK 0x1F - -struct orion_spi { - struct work_struct work; - - /* Lock access to transfer list. */ - spinlock_t lock; - - struct list_head msg_queue; - struct spi_master *master; - void __iomem *base; - unsigned int max_speed; - unsigned int min_speed; - struct orion_spi_info *spi_info; -}; - -static struct workqueue_struct *orion_spi_wq; - -static inline void __iomem *spi_reg(struct orion_spi *orion_spi, u32 reg) -{ - return orion_spi->base + reg; -} - -static inline void -orion_spi_setbits(struct orion_spi *orion_spi, u32 reg, u32 mask) -{ - void __iomem *reg_addr = spi_reg(orion_spi, reg); - u32 val; - - val = readl(reg_addr); - val |= mask; - writel(val, reg_addr); -} - -static inline void -orion_spi_clrbits(struct orion_spi *orion_spi, u32 reg, u32 mask) -{ - void __iomem *reg_addr = spi_reg(orion_spi, reg); - u32 val; - - val = readl(reg_addr); - val &= ~mask; - writel(val, reg_addr); -} - -static int orion_spi_set_transfer_size(struct orion_spi *orion_spi, int size) -{ - if (size == 16) { - orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG, - ORION_SPI_IF_8_16_BIT_MODE); - } else if (size == 8) { - orion_spi_clrbits(orion_spi, ORION_SPI_IF_CONFIG_REG, - ORION_SPI_IF_8_16_BIT_MODE); - } else { - pr_debug("Bad bits per word value %d (only 8 or 16 are " - "allowed).\n", size); - return -EINVAL; - } - - return 0; -} - -static int orion_spi_baudrate_set(struct spi_device *spi, unsigned int speed) -{ - u32 tclk_hz; - u32 rate; - u32 prescale; - u32 reg; - struct orion_spi *orion_spi; - - orion_spi = spi_master_get_devdata(spi->master); - - tclk_hz = orion_spi->spi_info->tclk; - - /* - * the supported rates are: 4,6,8...30 - * round up as we look for equal or less speed - */ - rate = DIV_ROUND_UP(tclk_hz, speed); - rate = roundup(rate, 2); - - /* check if requested speed is too small */ - if (rate > 30) - return -EINVAL; - - if (rate < 4) - rate = 4; - - /* Convert the rate to SPI clock divisor value. */ - prescale = 0x10 + rate/2; - - reg = readl(spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); - reg = ((reg & ~ORION_SPI_CLK_PRESCALE_MASK) | prescale); - writel(reg, spi_reg(orion_spi, ORION_SPI_IF_CONFIG_REG)); - - return 0; -} - -/* - * called only when no transfer is active on the bus - */ -static int -orion_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) -{ - struct orion_spi *orion_spi; - unsigned int speed = spi->max_speed_hz; - unsigned int bits_per_word = spi->bits_per_word; - int rc; - - orion_spi = spi_master_get_devdata(spi->master); - - if ((t != NULL) && t->speed_hz) - speed = t->speed_hz; - - if ((t != NULL) && t->bits_per_word) - bits_per_word = t->bits_per_word; - - rc = orion_spi_baudrate_set(spi, speed); - if (rc) - return rc; - - return orion_spi_set_transfer_size(orion_spi, bits_per_word); -} - -static void orion_spi_set_cs(struct orion_spi *orion_spi, int enable) -{ - if (enable) - orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1); - else - orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1); -} - -static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi) -{ - int i; - - for (i = 0; i < ORION_SPI_WAIT_RDY_MAX_LOOP; i++) { - if (readl(spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG))) - return 1; - else - udelay(1); - } - - return -1; -} - -static inline int -orion_spi_write_read_8bit(struct spi_device *spi, - const u8 **tx_buf, u8 **rx_buf) -{ - void __iomem *tx_reg, *rx_reg, *int_reg; - struct orion_spi *orion_spi; - - orion_spi = spi_master_get_devdata(spi->master); - tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG); - rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG); - int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG); - - /* clear the interrupt cause register */ - writel(0x0, int_reg); - - if (tx_buf && *tx_buf) - writel(*(*tx_buf)++, tx_reg); - else - writel(0, tx_reg); - - if (orion_spi_wait_till_ready(orion_spi) < 0) { - dev_err(&spi->dev, "TXS timed out\n"); - return -1; - } - - if (rx_buf && *rx_buf) - *(*rx_buf)++ = readl(rx_reg); - - return 1; -} - -static inline int -orion_spi_write_read_16bit(struct spi_device *spi, - const u16 **tx_buf, u16 **rx_buf) -{ - void __iomem *tx_reg, *rx_reg, *int_reg; - struct orion_spi *orion_spi; - - orion_spi = spi_master_get_devdata(spi->master); - tx_reg = spi_reg(orion_spi, ORION_SPI_DATA_OUT_REG); - rx_reg = spi_reg(orion_spi, ORION_SPI_DATA_IN_REG); - int_reg = spi_reg(orion_spi, ORION_SPI_INT_CAUSE_REG); - - /* clear the interrupt cause register */ - writel(0x0, int_reg); - - if (tx_buf && *tx_buf) - writel(__cpu_to_le16(get_unaligned((*tx_buf)++)), tx_reg); - else - writel(0, tx_reg); - - if (orion_spi_wait_till_ready(orion_spi) < 0) { - dev_err(&spi->dev, "TXS timed out\n"); - return -1; - } - - if (rx_buf && *rx_buf) - put_unaligned(__le16_to_cpu(readl(rx_reg)), (*rx_buf)++); - - return 1; -} - -static unsigned int -orion_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer) -{ - struct orion_spi *orion_spi; - unsigned int count; - int word_len; - - orion_spi = spi_master_get_devdata(spi->master); - word_len = spi->bits_per_word; - count = xfer->len; - - if (word_len == 8) { - const u8 *tx = xfer->tx_buf; - u8 *rx = xfer->rx_buf; - - do { - if (orion_spi_write_read_8bit(spi, &tx, &rx) < 0) - goto out; - count--; - } while (count); - } else if (word_len == 16) { - const u16 *tx = xfer->tx_buf; - u16 *rx = xfer->rx_buf; - - do { - if (orion_spi_write_read_16bit(spi, &tx, &rx) < 0) - goto out; - count -= 2; - } while (count); - } - -out: - return xfer->len - count; -} - - -static void orion_spi_work(struct work_struct *work) -{ - struct orion_spi *orion_spi = - container_of(work, struct orion_spi, work); - - spin_lock_irq(&orion_spi->lock); - while (!list_empty(&orion_spi->msg_queue)) { - struct spi_message *m; - struct spi_device *spi; - struct spi_transfer *t = NULL; - int par_override = 0; - int status = 0; - int cs_active = 0; - - m = container_of(orion_spi->msg_queue.next, struct spi_message, - queue); - - list_del_init(&m->queue); - spin_unlock_irq(&orion_spi->lock); - - spi = m->spi; - - /* Load defaults */ - status = orion_spi_setup_transfer(spi, NULL); - - if (status < 0) - goto msg_done; - - list_for_each_entry(t, &m->transfers, transfer_list) { - if (par_override || t->speed_hz || t->bits_per_word) { - par_override = 1; - status = orion_spi_setup_transfer(spi, t); - if (status < 0) - break; - if (!t->speed_hz && !t->bits_per_word) - par_override = 0; - } - - if (!cs_active) { - orion_spi_set_cs(orion_spi, 1); - cs_active = 1; - } - - if (t->len) - m->actual_length += - orion_spi_write_read(spi, t); - - if (t->delay_usecs) - udelay(t->delay_usecs); - - if (t->cs_change) { - orion_spi_set_cs(orion_spi, 0); - cs_active = 0; - } - } - -msg_done: - if (cs_active) - orion_spi_set_cs(orion_spi, 0); - - m->status = status; - m->complete(m->context); - - spin_lock_irq(&orion_spi->lock); - } - - spin_unlock_irq(&orion_spi->lock); -} - -static int __init orion_spi_reset(struct orion_spi *orion_spi) -{ - /* Verify that the CS is deasserted */ - orion_spi_set_cs(orion_spi, 0); - - return 0; -} - -static int orion_spi_setup(struct spi_device *spi) -{ - struct orion_spi *orion_spi; - - orion_spi = spi_master_get_devdata(spi->master); - - /* Fix ac timing if required. */ - if (orion_spi->spi_info->enable_clock_fix) - orion_spi_setbits(orion_spi, ORION_SPI_IF_CONFIG_REG, - (1 << 14)); - - if ((spi->max_speed_hz == 0) - || (spi->max_speed_hz > orion_spi->max_speed)) - spi->max_speed_hz = orion_spi->max_speed; - - if (spi->max_speed_hz < orion_spi->min_speed) { - dev_err(&spi->dev, "setup: requested speed too low %d Hz\n", - spi->max_speed_hz); - return -EINVAL; - } - - /* - * baudrate & width will be set orion_spi_setup_transfer - */ - return 0; -} - -static int orion_spi_transfer(struct spi_device *spi, struct spi_message *m) -{ - struct orion_spi *orion_spi; - struct spi_transfer *t = NULL; - unsigned long flags; - - m->actual_length = 0; - m->status = 0; - - /* reject invalid messages and transfers */ - if (list_empty(&m->transfers) || !m->complete) - return -EINVAL; - - orion_spi = spi_master_get_devdata(spi->master); - - list_for_each_entry(t, &m->transfers, transfer_list) { - unsigned int bits_per_word = spi->bits_per_word; - - if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) { - dev_err(&spi->dev, - "message rejected : " - "invalid transfer data buffers\n"); - goto msg_rejected; - } - - if (t->bits_per_word) - bits_per_word = t->bits_per_word; - - if ((bits_per_word != 8) && (bits_per_word != 16)) { - dev_err(&spi->dev, - "message rejected : " - "invalid transfer bits_per_word (%d bits)\n", - bits_per_word); - goto msg_rejected; - } - /*make sure buffer length is even when working in 16 bit mode*/ - if ((t->bits_per_word == 16) && (t->len & 1)) { - dev_err(&spi->dev, - "message rejected : " - "odd data length (%d) while in 16 bit mode\n", - t->len); - goto msg_rejected; - } - - if (t->speed_hz && t->speed_hz < orion_spi->min_speed) { - dev_err(&spi->dev, - "message rejected : " - "device min speed (%d Hz) exceeds " - "required transfer speed (%d Hz)\n", - orion_spi->min_speed, t->speed_hz); - goto msg_rejected; - } - } - - - spin_lock_irqsave(&orion_spi->lock, flags); - list_add_tail(&m->queue, &orion_spi->msg_queue); - queue_work(orion_spi_wq, &orion_spi->work); - spin_unlock_irqrestore(&orion_spi->lock, flags); - - return 0; -msg_rejected: - /* Message rejected and not queued */ - m->status = -EINVAL; - if (m->complete) - m->complete(m->context); - return -EINVAL; -} - -static int __init orion_spi_probe(struct platform_device *pdev) -{ - struct spi_master *master; - struct orion_spi *spi; - struct resource *r; - struct orion_spi_info *spi_info; - int status = 0; - - spi_info = pdev->dev.platform_data; - - master = spi_alloc_master(&pdev->dev, sizeof *spi); - if (master == NULL) { - dev_dbg(&pdev->dev, "master allocation failed\n"); - return -ENOMEM; - } - - if (pdev->id != -1) - master->bus_num = pdev->id; - - /* we support only mode 0, and no options */ - master->mode_bits = 0; - - master->setup = orion_spi_setup; - master->transfer = orion_spi_transfer; - master->num_chipselect = ORION_NUM_CHIPSELECTS; - - dev_set_drvdata(&pdev->dev, master); - - spi = spi_master_get_devdata(master); - spi->master = master; - spi->spi_info = spi_info; - - spi->max_speed = DIV_ROUND_UP(spi_info->tclk, 4); - spi->min_speed = DIV_ROUND_UP(spi_info->tclk, 30); - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (r == NULL) { - status = -ENODEV; - goto out; - } - - if (!request_mem_region(r->start, (r->end - r->start) + 1, - dev_name(&pdev->dev))) { - status = -EBUSY; - goto out; - } - spi->base = ioremap(r->start, SZ_1K); - - INIT_WORK(&spi->work, orion_spi_work); - - spin_lock_init(&spi->lock); - INIT_LIST_HEAD(&spi->msg_queue); - - if (orion_spi_reset(spi) < 0) - goto out_rel_mem; - - status = spi_register_master(master); - if (status < 0) - goto out_rel_mem; - - return status; - -out_rel_mem: - release_mem_region(r->start, (r->end - r->start) + 1); - -out: - spi_master_put(master); - return status; -} - - -static int __exit orion_spi_remove(struct platform_device *pdev) -{ - struct spi_master *master; - struct orion_spi *spi; - struct resource *r; - - master = dev_get_drvdata(&pdev->dev); - spi = spi_master_get_devdata(master); - - cancel_work_sync(&spi->work); - - r = platform_get_resource(pdev, IORESOURCE_MEM, 0); - release_mem_region(r->start, (r->end - r->start) + 1); - - spi_unregister_master(master); - - return 0; -} - -MODULE_ALIAS("platform:" DRIVER_NAME); - -static struct platform_driver orion_spi_driver = { - .driver = { - .name = DRIVER_NAME, - .owner = THIS_MODULE, - }, - .remove = __exit_p(orion_spi_remove), -}; - -static int __init orion_spi_init(void) -{ - orion_spi_wq = create_singlethread_workqueue( - orion_spi_driver.driver.name); - if (orion_spi_wq == NULL) - return -ENOMEM; - - return platform_driver_probe(&orion_spi_driver, orion_spi_probe); -} -module_init(orion_spi_init); - -static void __exit orion_spi_exit(void) -{ - flush_workqueue(orion_spi_wq); - platform_driver_unregister(&orion_spi_driver); - - destroy_workqueue(orion_spi_wq); -} -module_exit(orion_spi_exit); - -MODULE_DESCRIPTION("Orion SPI driver"); -MODULE_AUTHOR("Shadi Ammouri <shadi@marvell.com>"); -MODULE_LICENSE("GPL"); |