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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 | /* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2011, 2012 Cavium, Inc. */ #include <linux/spi/spi.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/io.h> #include "spi-cavium.h" static void octeon_spi_wait_ready(struct octeon_spi *p) { union cvmx_mpi_sts mpi_sts; unsigned int loops = 0; do { if (loops++) __delay(500); mpi_sts.u64 = readq(p->register_base + OCTEON_SPI_STS(p)); } while (mpi_sts.s.busy); } static int octeon_spi_do_transfer(struct octeon_spi *p, struct spi_message *msg, struct spi_transfer *xfer, bool last_xfer) { struct spi_device *spi = msg->spi; union cvmx_mpi_cfg mpi_cfg; union cvmx_mpi_tx mpi_tx; unsigned int clkdiv; int mode; bool cpha, cpol; const u8 *tx_buf; u8 *rx_buf; int len; int i; mode = spi->mode; cpha = mode & SPI_CPHA; cpol = mode & SPI_CPOL; clkdiv = p->sys_freq / (2 * xfer->speed_hz); mpi_cfg.u64 = 0; mpi_cfg.s.clkdiv = clkdiv; mpi_cfg.s.cshi = (mode & SPI_CS_HIGH) ? 1 : 0; mpi_cfg.s.lsbfirst = (mode & SPI_LSB_FIRST) ? 1 : 0; mpi_cfg.s.wireor = (mode & SPI_3WIRE) ? 1 : 0; mpi_cfg.s.idlelo = cpha != cpol; mpi_cfg.s.cslate = cpha ? 1 : 0; mpi_cfg.s.enable = 1; if (spi->chip_select < 4) p->cs_enax |= 1ull << (12 + spi->chip_select); mpi_cfg.u64 |= p->cs_enax; if (mpi_cfg.u64 != p->last_cfg) { p->last_cfg = mpi_cfg.u64; writeq(mpi_cfg.u64, p->register_base + OCTEON_SPI_CFG(p)); } tx_buf = xfer->tx_buf; rx_buf = xfer->rx_buf; len = xfer->len; while (len > OCTEON_SPI_MAX_BYTES) { for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) { u8 d; if (tx_buf) d = *tx_buf++; else d = 0; writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); } mpi_tx.u64 = 0; mpi_tx.s.csid = spi->chip_select; mpi_tx.s.leavecs = 1; mpi_tx.s.txnum = tx_buf ? OCTEON_SPI_MAX_BYTES : 0; mpi_tx.s.totnum = OCTEON_SPI_MAX_BYTES; writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p)); octeon_spi_wait_ready(p); if (rx_buf) for (i = 0; i < OCTEON_SPI_MAX_BYTES; i++) { u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); *rx_buf++ = (u8)v; } len -= OCTEON_SPI_MAX_BYTES; } for (i = 0; i < len; i++) { u8 d; if (tx_buf) d = *tx_buf++; else d = 0; writeq(d, p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); } mpi_tx.u64 = 0; mpi_tx.s.csid = spi->chip_select; if (last_xfer) mpi_tx.s.leavecs = xfer->cs_change; else mpi_tx.s.leavecs = !xfer->cs_change; mpi_tx.s.txnum = tx_buf ? len : 0; mpi_tx.s.totnum = len; writeq(mpi_tx.u64, p->register_base + OCTEON_SPI_TX(p)); octeon_spi_wait_ready(p); if (rx_buf) for (i = 0; i < len; i++) { u64 v = readq(p->register_base + OCTEON_SPI_DAT0(p) + (8 * i)); *rx_buf++ = (u8)v; } if (xfer->delay_usecs) udelay(xfer->delay_usecs); return xfer->len; } int octeon_spi_transfer_one_message(struct spi_master *master, struct spi_message *msg) { struct octeon_spi *p = spi_master_get_devdata(master); unsigned int total_len = 0; int status = 0; struct spi_transfer *xfer; list_for_each_entry(xfer, &msg->transfers, transfer_list) { bool last_xfer = list_is_last(&xfer->transfer_list, &msg->transfers); int r = octeon_spi_do_transfer(p, msg, xfer, last_xfer); if (r < 0) { status = r; goto err; } total_len += r; } err: msg->status = status; msg->actual_length = total_len; spi_finalize_current_message(master); return status; } |