diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/orion_spi.c | 574 |
3 files changed, 581 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 2303521..b9d0efb 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -149,6 +149,12 @@ config SPI_OMAP24XX SPI master controller for OMAP24xx/OMAP34xx Multichannel SPI (McSPI) modules. +config SPI_ORION + tristate "Orion SPI master (EXPERIMENTAL)" + depends on PLAT_ORION && EXPERIMENTAL + help + This enables using the SPI master controller on the Orion chips. + config SPI_PXA2XX tristate "PXA2xx SSP SPI master" depends on ARCH_PXA && EXPERIMENTAL diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 7fca043..ccf18de 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o obj-$(CONFIG_SPI_OMAP_UWIRE) += omap_uwire.o obj-$(CONFIG_SPI_OMAP24XX) += omap2_mcspi.o +obj-$(CONFIG_SPI_ORION) += orion_spi.o obj-$(CONFIG_SPI_MPC52xx_PSC) += mpc52xx_psc_spi.o obj-$(CONFIG_SPI_MPC83xx) += spi_mpc83xx.o obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o diff --git a/drivers/spi/orion_spi.c b/drivers/spi/orion_spi.c new file mode 100644 index 0000000..c4eaacd --- /dev/null +++ b/drivers/spi/orion_spi.c @@ -0,0 +1,574 @@ +/* + * 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); + + if (spi->mode) { + dev_err(&spi->dev, "setup: unsupported mode bits %x\n", + spi->mode); + return -EINVAL; + } + + if (spi->bits_per_word == 0) + spi->bits_per_word = 8; + + 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 != NULL) && 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 != NULL) && (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 < 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; + + 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, + pdev->dev.bus_id)) { + 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"); |