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150 lines
3.5 KiB
150 lines
3.5 KiB
/* |
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* This file is subject to the terms and conditions of the GNU General Public |
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* License. See the file "COPYING" in the main directory of this archive |
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* for more details. |
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* |
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* Copyright (C) 2011, 2012 Cavium, Inc. |
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*/ |
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#include <linux/spi/spi.h> |
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#include <linux/module.h> |
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#include <linux/delay.h> |
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#include <linux/io.h> |
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#include "spi-cavium.h" |
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static void octeon_spi_wait_ready(struct octeon_spi *p) |
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{ |
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union cvmx_mpi_sts mpi_sts; |
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unsigned int loops = 0; |
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do { |
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if (loops++) |
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__delay(500); |
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mpi_sts.u64 = readq(p->register_base + OCTEON_SPI_STS(p)); |
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} while (mpi_sts.s.busy); |
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} |
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static int octeon_spi_do_transfer(struct octeon_spi *p, |
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struct spi_message *msg, |
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struct spi_transfer *xfer, |
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bool last_xfer) |
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{ |
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struct spi_device *spi = msg->spi; |
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union cvmx_mpi_cfg mpi_cfg; |
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union cvmx_mpi_tx mpi_tx; |
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unsigned int clkdiv; |
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int mode; |
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bool cpha, cpol; |
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const u8 *tx_buf; |
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u8 *rx_buf; |
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int len; |
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int i; |
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mode = spi->mode; |
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cpha = mode & SPI_CPHA; |
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cpol = mode & SPI_CPOL; |
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clkdiv = p->sys_freq / (2 * xfer->speed_hz); |
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mpi_cfg.u64 = 0; |
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mpi_cfg.s.clkdiv = clkdiv; |
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mpi_cfg.s.cshi = (mode & SPI_CS_HIGH) ? 1 : 0; |
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mpi_cfg.s.lsbfirst = (mode & SPI_LSB_FIRST) ? 1 : 0; |
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mpi_cfg.s.wireor = (mode & SPI_3WIRE) ? 1 : 0; |
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mpi_cfg.s.idlelo = cpha != cpol; |
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mpi_cfg.s.cslate = cpha ? 1 : 0; |
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mpi_cfg.s.enable = 1; |
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if (spi->chip_select < 4) |
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p->cs_enax |= 1ull << (12 + spi->chip_select); |
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mpi_cfg.u64 |= p->cs_enax; |
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if (mpi_cfg.u64 != p->last_cfg) { |
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p->last_cfg = mpi_cfg.u64; |
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writeq(mpi_cfg.u64, p->register_base + OCTEON_SPI_CFG(p)); |
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} |
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tx_buf = xfer->tx_buf; |
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rx_buf = xfer->rx_buf; |
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len = xfer->len; |
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while (len > OCTEON_SPI_MAX_BYTES) { |
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for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) { |
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u8 d; |
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if (tx_buf) |
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d = *tx_buf++; |
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else |
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d = 0; |
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writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); |
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} |
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mpi_tx.u64 = 0; |
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mpi_tx.s.csid = spi->chip_select; |
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mpi_tx.s.leavecs = 1; |
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mpi_tx.s.txnum = tx_buf ? OCTEON_SPI_MAX_BYTES : 0; |
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mpi_tx.s.totnum = OCTEON_SPI_MAX_BYTES; |
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writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p)); |
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octeon_spi_wait_ready(p); |
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if (rx_buf) |
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for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) { |
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u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); |
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*rx_buf++ = (u8)v; |
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} |
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len -= OCTEON_SPI_MAX_BYTES; |
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} |
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for (i = 0; i < len; i++) { |
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u8 d; |
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if (tx_buf) |
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d = *tx_buf++; |
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else |
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d = 0; |
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writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); |
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} |
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mpi_tx.u64 = 0; |
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mpi_tx.s.csid = spi->chip_select; |
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if (last_xfer) |
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mpi_tx.s.leavecs = xfer->cs_change; |
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else |
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mpi_tx.s.leavecs = !xfer->cs_change; |
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mpi_tx.s.txnum = tx_buf ? len : 0; |
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mpi_tx.s.totnum = len; |
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writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p)); |
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octeon_spi_wait_ready(p); |
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if (rx_buf) |
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for (i = 0; i < len; i++) { |
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u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); |
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*rx_buf++ = (u8)v; |
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} |
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spi_transfer_delay_exec(xfer); |
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return xfer->len; |
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} |
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int octeon_spi_transfer_one_message(struct spi_master *master, |
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struct spi_message *msg) |
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{ |
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struct octeon_spi *p = spi_master_get_devdata(master); |
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unsigned int total_len = 0; |
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int status = 0; |
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struct spi_transfer *xfer; |
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list_for_each_entry(xfer, &msg->transfers, transfer_list) { |
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bool last_xfer = list_is_last(&xfer->transfer_list, |
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&msg->transfers); |
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int r = octeon_spi_do_transfer(p, msg, xfer, last_xfer); |
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if (r < 0) { |
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status = r; |
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goto err; |
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} |
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total_len += r; |
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} |
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err: |
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msg->status = status; |
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msg->actual_length = total_len; |
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spi_finalize_current_message(master); |
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return status; |
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}
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