| 1 | From cde4384e1037c15e5dd04c68d19c75798b6281dd Mon Sep 17 00:00:00 2001 |
| 2 | From: Florian Fainelli <florian@openwrt.org> |
| 3 | Date: Fri, 20 Apr 2012 15:37:33 +0200 |
| 4 | Subject: [PATCH] spi/bcm63xx: convert to the pump message infrastructure |
| 5 | |
| 6 | This patch converts the bcm63xx SPI driver to use the SPI infrastructure |
| 7 | pump message queue. Since we were previously sleeping in the SPI |
| 8 | driver's transfer() function (which is not allowed) this is now fixed as well. |
| 9 | |
| 10 | To complete that conversion a certain number of changes have been made: |
| 11 | - the transfer len is split into multiple hardware transfers in case its |
| 12 | size is bigger than the hardware FIFO size |
| 13 | - the FIFO refill is no longer done in the interrupt context, which was a |
| 14 | bad idea leading to quick interrupt handler re-entrancy |
| 15 | |
| 16 | Tested-by: Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com> |
| 17 | Signed-off-by: Florian Fainelli <florian@openwrt.org> |
| 18 | Signed-off-by: Grant Likely <grant.likely@secretlab.ca> |
| 19 | --- |
| 20 | drivers/spi/spi-bcm63xx.c | 149 +++++++++++++++++++++++++++------------------ |
| 21 | 1 file changed, 89 insertions(+), 60 deletions(-) |
| 22 | |
| 23 | --- a/drivers/spi/spi-bcm63xx.c |
| 24 | +++ b/drivers/spi/spi-bcm63xx.c |
| 25 | @@ -1,7 +1,7 @@ |
| 26 | /* |
| 27 | * Broadcom BCM63xx SPI controller support |
| 28 | * |
| 29 | - * Copyright (C) 2009-2011 Florian Fainelli <florian@openwrt.org> |
| 30 | + * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org> |
| 31 | * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com> |
| 32 | * |
| 33 | * This program is free software; you can redistribute it and/or |
| 34 | @@ -30,6 +30,8 @@ |
| 35 | #include <linux/spi/spi.h> |
| 36 | #include <linux/completion.h> |
| 37 | #include <linux/err.h> |
| 38 | +#include <linux/workqueue.h> |
| 39 | +#include <linux/pm_runtime.h> |
| 40 | |
| 41 | #include <bcm63xx_dev_spi.h> |
| 42 | |
| 43 | @@ -96,17 +98,12 @@ static const unsigned bcm63xx_spi_freq_t |
| 44 | { 391000, SPI_CLK_0_391MHZ } |
| 45 | }; |
| 46 | |
| 47 | -static int bcm63xx_spi_setup_transfer(struct spi_device *spi, |
| 48 | - struct spi_transfer *t) |
| 49 | +static int bcm63xx_spi_check_transfer(struct spi_device *spi, |
| 50 | + struct spi_transfer *t) |
| 51 | { |
| 52 | - struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); |
| 53 | u8 bits_per_word; |
| 54 | - u8 clk_cfg, reg; |
| 55 | - u32 hz; |
| 56 | - int i; |
| 57 | |
| 58 | bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word; |
| 59 | - hz = (t) ? t->speed_hz : spi->max_speed_hz; |
| 60 | if (bits_per_word != 8) { |
| 61 | dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n", |
| 62 | __func__, bits_per_word); |
| 63 | @@ -119,6 +116,19 @@ static int bcm63xx_spi_setup_transfer(st |
| 64 | return -EINVAL; |
| 65 | } |
| 66 | |
| 67 | + return 0; |
| 68 | +} |
| 69 | + |
| 70 | +static void bcm63xx_spi_setup_transfer(struct spi_device *spi, |
| 71 | + struct spi_transfer *t) |
| 72 | +{ |
| 73 | + struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); |
| 74 | + u32 hz; |
| 75 | + u8 clk_cfg, reg; |
| 76 | + int i; |
| 77 | + |
| 78 | + hz = (t) ? t->speed_hz : spi->max_speed_hz; |
| 79 | + |
| 80 | /* Find the closest clock configuration */ |
| 81 | for (i = 0; i < SPI_CLK_MASK; i++) { |
| 82 | if (hz >= bcm63xx_spi_freq_table[i][0]) { |
| 83 | @@ -139,8 +149,6 @@ static int bcm63xx_spi_setup_transfer(st |
| 84 | bcm_spi_writeb(bs, reg, SPI_CLK_CFG); |
| 85 | dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n", |
| 86 | clk_cfg, hz); |
| 87 | - |
| 88 | - return 0; |
| 89 | } |
| 90 | |
| 91 | /* the spi->mode bits understood by this driver: */ |
| 92 | @@ -165,7 +173,7 @@ static int bcm63xx_spi_setup(struct spi_ |
| 93 | return -EINVAL; |
| 94 | } |
| 95 | |
| 96 | - ret = bcm63xx_spi_setup_transfer(spi, NULL); |
| 97 | + ret = bcm63xx_spi_check_transfer(spi, NULL); |
| 98 | if (ret < 0) { |
| 99 | dev_err(&spi->dev, "setup: unsupported mode bits %x\n", |
| 100 | spi->mode & ~MODEBITS); |
| 101 | @@ -190,28 +198,29 @@ static void bcm63xx_spi_fill_tx_fifo(str |
| 102 | bs->remaining_bytes -= size; |
| 103 | } |
| 104 | |
| 105 | -static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) |
| 106 | +static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi, |
| 107 | + struct spi_transfer *t) |
| 108 | { |
| 109 | struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); |
| 110 | u16 msg_ctl; |
| 111 | u16 cmd; |
| 112 | |
| 113 | + /* Disable the CMD_DONE interrupt */ |
| 114 | + bcm_spi_writeb(bs, 0, SPI_INT_MASK); |
| 115 | + |
| 116 | dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", |
| 117 | t->tx_buf, t->rx_buf, t->len); |
| 118 | |
| 119 | /* Transmitter is inhibited */ |
| 120 | bs->tx_ptr = t->tx_buf; |
| 121 | bs->rx_ptr = t->rx_buf; |
| 122 | - init_completion(&bs->done); |
| 123 | |
| 124 | if (t->tx_buf) { |
| 125 | bs->remaining_bytes = t->len; |
| 126 | bcm63xx_spi_fill_tx_fifo(bs); |
| 127 | } |
| 128 | |
| 129 | - /* Enable the command done interrupt which |
| 130 | - * we use to determine completion of a command */ |
| 131 | - bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK); |
| 132 | + init_completion(&bs->done); |
| 133 | |
| 134 | /* Fill in the Message control register */ |
| 135 | msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT); |
| 136 | @@ -230,33 +239,76 @@ static int bcm63xx_txrx_bufs(struct spi_ |
| 137 | cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); |
| 138 | cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT); |
| 139 | bcm_spi_writew(bs, cmd, SPI_CMD); |
| 140 | - wait_for_completion(&bs->done); |
| 141 | |
| 142 | - /* Disable the CMD_DONE interrupt */ |
| 143 | - bcm_spi_writeb(bs, 0, SPI_INT_MASK); |
| 144 | + /* Enable the CMD_DONE interrupt */ |
| 145 | + bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK); |
| 146 | |
| 147 | return t->len - bs->remaining_bytes; |
| 148 | } |
| 149 | |
| 150 | -static int bcm63xx_transfer(struct spi_device *spi, struct spi_message *m) |
| 151 | +static int bcm63xx_spi_prepare_transfer(struct spi_master *master) |
| 152 | { |
| 153 | - struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master); |
| 154 | - struct spi_transfer *t; |
| 155 | - int ret = 0; |
| 156 | + struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
| 157 | |
| 158 | - if (unlikely(list_empty(&m->transfers))) |
| 159 | - return -EINVAL; |
| 160 | + pm_runtime_get_sync(&bs->pdev->dev); |
| 161 | |
| 162 | - if (bs->stopping) |
| 163 | - return -ESHUTDOWN; |
| 164 | + return 0; |
| 165 | +} |
| 166 | + |
| 167 | +static int bcm63xx_spi_unprepare_transfer(struct spi_master *master) |
| 168 | +{ |
| 169 | + struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
| 170 | + |
| 171 | + pm_runtime_put(&bs->pdev->dev); |
| 172 | + |
| 173 | + return 0; |
| 174 | +} |
| 175 | + |
| 176 | +static int bcm63xx_spi_transfer_one(struct spi_master *master, |
| 177 | + struct spi_message *m) |
| 178 | +{ |
| 179 | + struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
| 180 | + struct spi_transfer *t; |
| 181 | + struct spi_device *spi = m->spi; |
| 182 | + int status = 0; |
| 183 | + unsigned int timeout = 0; |
| 184 | |
| 185 | list_for_each_entry(t, &m->transfers, transfer_list) { |
| 186 | - ret += bcm63xx_txrx_bufs(spi, t); |
| 187 | - } |
| 188 | + unsigned int len = t->len; |
| 189 | + u8 rx_tail; |
| 190 | |
| 191 | - m->complete(m->context); |
| 192 | + status = bcm63xx_spi_check_transfer(spi, t); |
| 193 | + if (status < 0) |
| 194 | + goto exit; |
| 195 | + |
| 196 | + /* configure adapter for a new transfer */ |
| 197 | + bcm63xx_spi_setup_transfer(spi, t); |
| 198 | + |
| 199 | + while (len) { |
| 200 | + /* send the data */ |
| 201 | + len -= bcm63xx_txrx_bufs(spi, t); |
| 202 | + |
| 203 | + timeout = wait_for_completion_timeout(&bs->done, HZ); |
| 204 | + if (!timeout) { |
| 205 | + status = -ETIMEDOUT; |
| 206 | + goto exit; |
| 207 | + } |
| 208 | + |
| 209 | + /* read out all data */ |
| 210 | + rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL); |
| 211 | + |
| 212 | + /* Read out all the data */ |
| 213 | + if (rx_tail) |
| 214 | + memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail); |
| 215 | + } |
| 216 | + |
| 217 | + m->actual_length += t->len; |
| 218 | + } |
| 219 | +exit: |
| 220 | + m->status = status; |
| 221 | + spi_finalize_current_message(master); |
| 222 | |
| 223 | - return ret; |
| 224 | + return 0; |
| 225 | } |
| 226 | |
| 227 | /* This driver supports single master mode only. Hence |
| 228 | @@ -267,39 +319,15 @@ static irqreturn_t bcm63xx_spi_interrupt |
| 229 | struct spi_master *master = (struct spi_master *)dev_id; |
| 230 | struct bcm63xx_spi *bs = spi_master_get_devdata(master); |
| 231 | u8 intr; |
| 232 | - u16 cmd; |
| 233 | |
| 234 | /* Read interupts and clear them immediately */ |
| 235 | intr = bcm_spi_readb(bs, SPI_INT_STATUS); |
| 236 | bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS); |
| 237 | bcm_spi_writeb(bs, 0, SPI_INT_MASK); |
| 238 | |
| 239 | - /* A tansfer completed */ |
| 240 | - if (intr & SPI_INTR_CMD_DONE) { |
| 241 | - u8 rx_tail; |
| 242 | - |
| 243 | - rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL); |
| 244 | - |
| 245 | - /* Read out all the data */ |
| 246 | - if (rx_tail) |
| 247 | - memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail); |
| 248 | - |
| 249 | - /* See if there is more data to send */ |
| 250 | - if (bs->remaining_bytes > 0) { |
| 251 | - bcm63xx_spi_fill_tx_fifo(bs); |
| 252 | - |
| 253 | - /* Start the transfer */ |
| 254 | - bcm_spi_writew(bs, SPI_HD_W << SPI_MSG_TYPE_SHIFT, |
| 255 | - SPI_MSG_CTL); |
| 256 | - cmd = bcm_spi_readw(bs, SPI_CMD); |
| 257 | - cmd |= SPI_CMD_START_IMMEDIATE; |
| 258 | - cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT); |
| 259 | - bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK); |
| 260 | - bcm_spi_writew(bs, cmd, SPI_CMD); |
| 261 | - } else { |
| 262 | - complete(&bs->done); |
| 263 | - } |
| 264 | - } |
| 265 | + /* A transfer completed */ |
| 266 | + if (intr & SPI_INTR_CMD_DONE) |
| 267 | + complete(&bs->done); |
| 268 | |
| 269 | return IRQ_HANDLED; |
| 270 | } |
| 271 | @@ -345,7 +373,6 @@ static int __devinit bcm63xx_spi_probe(s |
| 272 | } |
| 273 | |
| 274 | bs = spi_master_get_devdata(master); |
| 275 | - init_completion(&bs->done); |
| 276 | |
| 277 | platform_set_drvdata(pdev, master); |
| 278 | bs->pdev = pdev; |
| 279 | @@ -379,7 +406,9 @@ static int __devinit bcm63xx_spi_probe(s |
| 280 | master->bus_num = pdata->bus_num; |
| 281 | master->num_chipselect = pdata->num_chipselect; |
| 282 | master->setup = bcm63xx_spi_setup; |
| 283 | - master->transfer = bcm63xx_transfer; |
| 284 | + master->prepare_transfer_hardware = bcm63xx_spi_prepare_transfer; |
| 285 | + master->unprepare_transfer_hardware = bcm63xx_spi_unprepare_transfer; |
| 286 | + master->transfer_one_message = bcm63xx_spi_transfer_one; |
| 287 | bs->speed_hz = pdata->speed_hz; |
| 288 | bs->stopping = 0; |
| 289 | bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA)); |
| 290 | |
