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