diff options
Diffstat (limited to 'drivers/spi/spi-ti-ssp.c')
-rw-r--r-- | drivers/spi/spi-ti-ssp.c | 378 |
1 files changed, 0 insertions, 378 deletions
diff --git a/drivers/spi/spi-ti-ssp.c b/drivers/spi/spi-ti-ssp.c deleted file mode 100644 index 7d20e121e4c..00000000000 --- a/drivers/spi/spi-ti-ssp.c +++ /dev/null @@ -1,378 +0,0 @@ -/* - * Sequencer Serial Port (SSP) based SPI master driver - * - * Copyright (C) 2010 Texas Instruments Inc - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that 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. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -#include <linux/kernel.h> -#include <linux/err.h> -#include <linux/completion.h> -#include <linux/delay.h> -#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/spi/spi.h> -#include <linux/mfd/ti_ssp.h> - -#define MODE_BITS (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH) - -struct ti_ssp_spi { - struct spi_master *master; - struct device *dev; - spinlock_t lock; - struct list_head msg_queue; - struct completion complete; - bool shutdown; - struct workqueue_struct *workqueue; - struct work_struct work; - u8 mode, bpw; - int cs_active; - u32 pc_en, pc_dis, pc_wr, pc_rd; - void (*select)(int cs); -}; - -static u32 ti_ssp_spi_rx(struct ti_ssp_spi *hw) -{ - u32 ret; - - ti_ssp_run(hw->dev, hw->pc_rd, 0, &ret); - return ret; -} - -static void ti_ssp_spi_tx(struct ti_ssp_spi *hw, u32 data) -{ - ti_ssp_run(hw->dev, hw->pc_wr, data << (32 - hw->bpw), NULL); -} - -static int ti_ssp_spi_txrx(struct ti_ssp_spi *hw, struct spi_message *msg, - struct spi_transfer *t) -{ - int count; - - if (hw->bpw <= 8) { - u8 *rx = t->rx_buf; - const u8 *tx = t->tx_buf; - - for (count = 0; count < t->len; count += 1) { - if (t->tx_buf) - ti_ssp_spi_tx(hw, *tx++); - if (t->rx_buf) - *rx++ = ti_ssp_spi_rx(hw); - } - } else if (hw->bpw <= 16) { - u16 *rx = t->rx_buf; - const u16 *tx = t->tx_buf; - - for (count = 0; count < t->len; count += 2) { - if (t->tx_buf) - ti_ssp_spi_tx(hw, *tx++); - if (t->rx_buf) - *rx++ = ti_ssp_spi_rx(hw); - } - } else { - u32 *rx = t->rx_buf; - const u32 *tx = t->tx_buf; - - for (count = 0; count < t->len; count += 4) { - if (t->tx_buf) - ti_ssp_spi_tx(hw, *tx++); - if (t->rx_buf) - *rx++ = ti_ssp_spi_rx(hw); - } - } - - msg->actual_length += count; /* bytes transferred */ - - dev_dbg(&msg->spi->dev, "xfer %s%s, %d bytes, %d bpw, count %d%s\n", - t->tx_buf ? "tx" : "", t->rx_buf ? "rx" : "", t->len, - hw->bpw, count, (count < t->len) ? " (under)" : ""); - - return (count < t->len) ? -EIO : 0; /* left over data */ -} - -static void ti_ssp_spi_chip_select(struct ti_ssp_spi *hw, int cs_active) -{ - cs_active = !!cs_active; - if (cs_active == hw->cs_active) - return; - ti_ssp_run(hw->dev, cs_active ? hw->pc_en : hw->pc_dis, 0, NULL); - hw->cs_active = cs_active; -} - -#define __SHIFT_OUT(bits) (SSP_OPCODE_SHIFT | SSP_OUT_MODE | \ - cs_en | clk | SSP_COUNT((bits) * 2 - 1)) -#define __SHIFT_IN(bits) (SSP_OPCODE_SHIFT | SSP_IN_MODE | \ - cs_en | clk | SSP_COUNT((bits) * 2 - 1)) - -static int ti_ssp_spi_setup_transfer(struct ti_ssp_spi *hw, u8 bpw, u8 mode) -{ - int error, idx = 0; - u32 seqram[16]; - u32 cs_en, cs_dis, clk; - u32 topbits, botbits; - - mode &= MODE_BITS; - if (mode == hw->mode && bpw == hw->bpw) - return 0; - - cs_en = (mode & SPI_CS_HIGH) ? SSP_CS_HIGH : SSP_CS_LOW; - cs_dis = (mode & SPI_CS_HIGH) ? SSP_CS_LOW : SSP_CS_HIGH; - clk = (mode & SPI_CPOL) ? SSP_CLK_HIGH : SSP_CLK_LOW; - - /* Construct instructions */ - - /* Disable Chip Select */ - hw->pc_dis = idx; - seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_dis | clk; - seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_dis | clk; - - /* Enable Chip Select */ - hw->pc_en = idx; - seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_en | clk; - seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; - - /* Reads and writes need to be split for bpw > 16 */ - topbits = (bpw > 16) ? 16 : bpw; - botbits = bpw - topbits; - - /* Write */ - hw->pc_wr = idx; - seqram[idx++] = __SHIFT_OUT(topbits) | SSP_ADDR_REG; - if (botbits) - seqram[idx++] = __SHIFT_OUT(botbits) | SSP_DATA_REG; - seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; - - /* Read */ - hw->pc_rd = idx; - if (botbits) - seqram[idx++] = __SHIFT_IN(botbits) | SSP_ADDR_REG; - seqram[idx++] = __SHIFT_IN(topbits) | SSP_DATA_REG; - seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk; - - error = ti_ssp_load(hw->dev, 0, seqram, idx); - if (error < 0) - return error; - - error = ti_ssp_set_mode(hw->dev, ((mode & SPI_CPHA) ? - 0 : SSP_EARLY_DIN)); - if (error < 0) - return error; - - hw->bpw = bpw; - hw->mode = mode; - - return error; -} - -static void ti_ssp_spi_work(struct work_struct *work) -{ - struct ti_ssp_spi *hw = container_of(work, struct ti_ssp_spi, work); - - spin_lock(&hw->lock); - - while (!list_empty(&hw->msg_queue)) { - struct spi_message *m; - struct spi_device *spi; - struct spi_transfer *t = NULL; - int status = 0; - - m = container_of(hw->msg_queue.next, struct spi_message, - queue); - - list_del_init(&m->queue); - - spin_unlock(&hw->lock); - - spi = m->spi; - - if (hw->select) - hw->select(spi->chip_select); - - list_for_each_entry(t, &m->transfers, transfer_list) { - int bpw = spi->bits_per_word; - int xfer_status; - - if (t->bits_per_word) - bpw = t->bits_per_word; - - if (ti_ssp_spi_setup_transfer(hw, bpw, spi->mode) < 0) - break; - - ti_ssp_spi_chip_select(hw, 1); - - xfer_status = ti_ssp_spi_txrx(hw, m, t); - if (xfer_status < 0) - status = xfer_status; - - if (t->delay_usecs) - udelay(t->delay_usecs); - - if (t->cs_change) - ti_ssp_spi_chip_select(hw, 0); - } - - ti_ssp_spi_chip_select(hw, 0); - m->status = status; - m->complete(m->context); - - spin_lock(&hw->lock); - } - - if (hw->shutdown) - complete(&hw->complete); - - spin_unlock(&hw->lock); -} - -static int ti_ssp_spi_transfer(struct spi_device *spi, struct spi_message *m) -{ - struct ti_ssp_spi *hw; - struct spi_transfer *t; - int error = 0; - - m->actual_length = 0; - m->status = -EINPROGRESS; - - hw = spi_master_get_devdata(spi->master); - - if (list_empty(&m->transfers) || !m->complete) - return -EINVAL; - - list_for_each_entry(t, &m->transfers, transfer_list) { - if (t->len && !(t->rx_buf || t->tx_buf)) { - dev_err(&spi->dev, "invalid xfer, no buffer\n"); - return -EINVAL; - } - - if (t->len && t->rx_buf && t->tx_buf) { - dev_err(&spi->dev, "invalid xfer, full duplex\n"); - return -EINVAL; - } - } - - spin_lock(&hw->lock); - if (hw->shutdown) { - error = -ESHUTDOWN; - goto error_unlock; - } - list_add_tail(&m->queue, &hw->msg_queue); - queue_work(hw->workqueue, &hw->work); -error_unlock: - spin_unlock(&hw->lock); - return error; -} - -static int ti_ssp_spi_probe(struct platform_device *pdev) -{ - const struct ti_ssp_spi_data *pdata; - struct ti_ssp_spi *hw; - struct spi_master *master; - struct device *dev = &pdev->dev; - int error = 0; - - pdata = dev_get_platdata(dev); - if (!pdata) { - dev_err(dev, "platform data not found\n"); - return -EINVAL; - } - - master = spi_alloc_master(dev, sizeof(struct ti_ssp_spi)); - if (!master) { - dev_err(dev, "cannot allocate SPI master\n"); - return -ENOMEM; - } - - hw = spi_master_get_devdata(master); - platform_set_drvdata(pdev, hw); - - hw->master = master; - hw->dev = dev; - hw->select = pdata->select; - - spin_lock_init(&hw->lock); - init_completion(&hw->complete); - INIT_LIST_HEAD(&hw->msg_queue); - INIT_WORK(&hw->work, ti_ssp_spi_work); - - hw->workqueue = create_singlethread_workqueue(dev_name(dev)); - if (!hw->workqueue) { - error = -ENOMEM; - dev_err(dev, "work queue creation failed\n"); - goto error_wq; - } - - error = ti_ssp_set_iosel(hw->dev, pdata->iosel); - if (error < 0) { - dev_err(dev, "io setup failed\n"); - goto error_iosel; - } - - master->bus_num = pdev->id; - master->num_chipselect = pdata->num_cs; - master->mode_bits = MODE_BITS; - master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); - master->flags = SPI_MASTER_HALF_DUPLEX; - master->transfer = ti_ssp_spi_transfer; - - error = spi_register_master(master); - if (error) { - dev_err(dev, "master registration failed\n"); - goto error_reg; - } - - return 0; - -error_reg: -error_iosel: - destroy_workqueue(hw->workqueue); -error_wq: - spi_master_put(master); - return error; -} - -static int ti_ssp_spi_remove(struct platform_device *pdev) -{ - struct ti_ssp_spi *hw = platform_get_drvdata(pdev); - int error; - - hw->shutdown = 1; - while (!list_empty(&hw->msg_queue)) { - error = wait_for_completion_interruptible(&hw->complete); - if (error < 0) { - hw->shutdown = 0; - return error; - } - } - destroy_workqueue(hw->workqueue); - spi_unregister_master(hw->master); - - return 0; -} - -static struct platform_driver ti_ssp_spi_driver = { - .probe = ti_ssp_spi_probe, - .remove = ti_ssp_spi_remove, - .driver = { - .name = "ti-ssp-spi", - .owner = THIS_MODULE, - }, -}; -module_platform_driver(ti_ssp_spi_driver); - -MODULE_DESCRIPTION("SSP SPI Master"); -MODULE_AUTHOR("Cyril Chemparathy"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:ti-ssp-spi"); |