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Message-Id: <20091125140422.cdee4a0d.akpm@linux-foundation.org>
Date: Wed, 25 Nov 2009 14:04:22 -0800
From: Andrew Morton <akpm@...ux-foundation.org>
To: <cliffcai.sh@...il.com>
Cc: <linux-mmc@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<cliff.cai@...log.com>, Bryan Wu <cooloney@...nel.org>,
Mike Frysinger <vapier@...too.org>
Subject: Re: [PATCH v4][mmc/host]:Blackfin SD Host Controller Driver
On Wed, 25 Nov 2009 23:19:50 +0800
<cliffcai.sh@...il.com> wrote:
> From: Cliff Cai <cliffcai.sh@...il.com>
>
> Add SD host driver for Blackfin BF54x and BF51x.
>
> Signed-off-by: Cliff Cai <cliffcai.sh@...il.com>
> Signed-off-by: Bryan Wu <cooloney@...nel.org>
> Signed-off-by: Mike Frysinger <vapier@...too.org>
>
> ...
>
>
> +config SDH_BFIN
> + tristate "Blackfin Secure Digital Host support"
> + depends on MMC && ((BF54x && !BF544) || (BF51x && !BF512))
> + help
> + If you say yes here you will get support for the Blackfin on-chip
> + Secure Digital Host interface. This includes support for MMC and
> + SD cards.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called bfin_sdh.
> +
> + If unsure, say N.
> +
> +config SDH_BFIN_MISSING_CMD_PULLUP_WORKAROUND
> + bool "Blackfin EZkit Missing SDH_CMD Pull Up Resistor Workaround"
> + depends on SDH_BFIN
> + help
> + If you say yes here SD-Cards may work on the EZkit.
Indenting is all mangled.
>
> ...
>
> +struct dma_desc_array {
> + unsigned long start_addr;
> + unsigned short cfg;
> + unsigned short x_count;
> + short x_modify;
> +} __attribute__((packed));
__packed is preferred.
> +struct sdh_host {
> + struct mmc_host *mmc;
> + spinlock_t lock;
> + struct resource *res;
> + void __iomem *base;
> + int irq;
> + int stat_irq;
> + int dma_ch;
> + int dma_dir;
> + struct dma_desc_array *sg_cpu;
> + dma_addr_t sg_dma;
> + int dma_len;
> +
> + unsigned int imask;
> + unsigned int power_mode;
> + unsigned int clk_div;
> +
> + struct mmc_request *mrq;
> + struct mmc_command *cmd;
> + struct mmc_data *data;
> +};
>
> ...
>
> +static int sdh_setup_data(struct sdh_host *host, struct mmc_data *data)
> +{
> + unsigned int length;
> + unsigned int data_ctl;
> + unsigned int dma_cfg;
> + struct scatterlist *sg;
> +
> + dev_dbg(mmc_dev(host->mmc), "%s enter flags: 0x%x\n", __func__, data->flags);
> + host->data = data;
> + data_ctl = 0;
> + dma_cfg = 0;
> +
> + length = data->blksz * data->blocks;
> + bfin_write_SDH_DATA_LGTH(length);
> +
> + if (data->flags & MMC_DATA_STREAM)
> + data_ctl |= DTX_MODE;
> +
> + if (data->flags & MMC_DATA_READ)
> + data_ctl |= DTX_DIR;
> + /* Only supports power-of-2 block size */
> + if (data->blksz & (data->blksz - 1))
> + return -EINVAL;
> + data_ctl |= ((ffs(data->blksz) - 1) << 4);
> +
> + bfin_write_SDH_DATA_CTL(data_ctl);
> +
> + bfin_write_SDH_DATA_TIMER(0xFFFF);
> + SSYNC();
> +
> + if (data->flags & MMC_DATA_READ) {
> + host->dma_dir = DMA_FROM_DEVICE;
> + dma_cfg |= WNR;
> + } else
> + host->dma_dir = DMA_TO_DEVICE;
> +
> + sdh_enable_stat_irq(host, (DAT_CRC_FAIL | DAT_TIME_OUT | DAT_END));
> + host->dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len, host->dma_dir);
> +#if defined(CONFIG_BF54x)
> + int i;
This is going to generate a compiler warning. We don't use the c99
declaration form in kernel code.
> + dma_cfg |= DMAFLOW_ARRAY | NDSIZE_5 | RESTART | WDSIZE_32 | DMAEN;
> + for_each_sg(data->sg, sg, host->dma_len, i) {
> + host->sg_cpu[i].start_addr = sg_dma_address(sg);
> + host->sg_cpu[i].cfg = dma_cfg;
> + host->sg_cpu[i].x_count = sg_dma_len(sg) / 4;
> + host->sg_cpu[i].x_modify = 4;
> + dev_dbg(mmc_dev(host->mmc), "%d: start_addr:0x%lx, cfg:0x%x, x_count:0x%x,\
> + x_modify:0x%x\n", i, host->sg_cpu[i].start_addr,
> + host->sg_cpu[i].cfg, host->sg_cpu[i].x_count,
> + host->sg_cpu[i].x_modify);
> + }
> + flush_dcache_range((unsigned int)host->sg_cpu,
> + (unsigned int)host->sg_cpu +
> + host->dma_len * sizeof(struct dma_desc_array));
> + /* Set the last descriptor to stop mode */
> + host->sg_cpu[host->dma_len - 1].cfg &= ~(DMAFLOW | NDSIZE);
> + host->sg_cpu[host->dma_len - 1].cfg |= DI_EN;
> +
> + set_dma_curr_desc_addr(host->dma_ch, (unsigned long *)host->sg_dma);
> + set_dma_x_count(host->dma_ch, 0);
> + set_dma_x_modify(host->dma_ch, 0);
> + set_dma_config(host->dma_ch, dma_cfg);
> +#elif defined(CONFIG_BF51x)
> + /* RSI DMA doesn't work in array mode */
> + dma_cfg |= WDSIZE_32 | DMAEN;
> + set_dma_start_addr(host->dma_ch, sg_dma_address(&data->sg[0]));
> + set_dma_x_count(host->dma_ch, length / 4);
> + set_dma_x_modify(host->dma_ch, 4);
> + set_dma_config(host->dma_ch, dma_cfg);
> +#endif
> + bfin_write_SDH_DATA_CTL(bfin_read_SDH_DATA_CTL() | DTX_DMA_E | DTX_E);
> +
> + SSYNC();
> +
> + dev_dbg(mmc_dev(host->mmc), "%s exit\n", __func__);
> + return 0;
> +}
> +
> +static void sdh_start_cmd(struct sdh_host *host, struct mmc_command *cmd)
> +{
> + unsigned int sdh_cmd;
> + unsigned int stat_mask;
> +
> + dev_dbg(mmc_dev(host->mmc), "%s enter cmd: 0x%p\n", __func__, cmd);
> + WARN_ON(host->cmd != NULL);
> + host->cmd = cmd;
> +
> + sdh_cmd = 0;
> + stat_mask = 0;
> +
> + sdh_cmd |= cmd->opcode;
> +
> + if (cmd->flags & MMC_RSP_PRESENT) {
> + sdh_cmd |= CMD_RSP;
> + stat_mask |= CMD_RESP_END;
> + } else
> + stat_mask |= CMD_SENT;
Arguably wrong from a coding-style POV and looks weird IMO. Adds a bit
of risk that subsequent coders will think they're writing in python adn
will add bugs.
> + if (cmd->flags & MMC_RSP_136)
> + sdh_cmd |= CMD_L_RSP;
> +
> + stat_mask |= CMD_CRC_FAIL | CMD_TIME_OUT;
> +
> + sdh_enable_stat_irq(host, stat_mask);
> +
> + bfin_write_SDH_ARGUMENT(cmd->arg);
> + bfin_write_SDH_COMMAND(sdh_cmd | CMD_E);
> + bfin_write_SDH_CLK_CTL(bfin_read_SDH_CLK_CTL() | CLK_E);
> + SSYNC();
> +}
> +
>
> ...
>
> +static irqreturn_t sdh_stat_irq(int irq, void *devid)
> +{
> + struct sdh_host *host = devid;
> + unsigned int status;
> + int handled = 0;
> +
> + dev_dbg(mmc_dev(host->mmc), "%s enter\n", __func__);
> + status = bfin_read_SDH_E_STATUS();
> + if (status & SD_CARD_DET) {
> + mmc_detect_change(host->mmc, 0);
> + bfin_write_SDH_E_STATUS(SD_CARD_DET);
> + }
> + status = bfin_read_SDH_STATUS();
> + if (status & (CMD_SENT | CMD_RESP_END | CMD_TIME_OUT | CMD_CRC_FAIL)) {
> + handled |= sdh_cmd_done(host, status);
> + bfin_write_SDH_STATUS_CLR( CMD_SENT_STAT | CMD_RESP_END_STAT | \
> + CMD_TIMEOUT_STAT | CMD_CRC_FAIL_STAT);
Please always use scripts/checkpatch.pl.
> + SSYNC();
> + }
> +
> + status = bfin_read_SDH_STATUS();
> + if (status & (DAT_END | DAT_TIME_OUT | DAT_CRC_FAIL | RX_OVERRUN | TX_UNDERRUN))
> + handled |= sdh_data_done(host, status);
> +
> + dev_dbg(mmc_dev(host->mmc), "%s exit\n\n", __func__);
> +
> + return IRQ_RETVAL(handled);
> +}
> +
>
> ...
>
Fixes:
diff -puN drivers/mmc/host/Kconfig~blackfin-sd-host-controller-driver-fix drivers/mmc/host/Kconfig
--- a/drivers/mmc/host/Kconfig~blackfin-sd-host-controller-driver-fix
+++ a/drivers/mmc/host/Kconfig
@@ -367,20 +367,20 @@ config MMC_VIA_SDMMC
If unsure, say N.
config SDH_BFIN
- tristate "Blackfin Secure Digital Host support"
- depends on MMC && ((BF54x && !BF544) || (BF51x && !BF512))
- help
- If you say yes here you will get support for the Blackfin on-chip
- Secure Digital Host interface. This includes support for MMC and
- SD cards.
+ tristate "Blackfin Secure Digital Host support"
+ depends on MMC && ((BF54x && !BF544) || (BF51x && !BF512))
+ help
+ If you say yes here you will get support for the Blackfin on-chip
+ Secure Digital Host interface. This includes support for MMC and
+ SD cards.
- To compile this driver as a module, choose M here: the
- module will be called bfin_sdh.
+ To compile this driver as a module, choose M here: the
+ module will be called bfin_sdh.
- If unsure, say N.
+ If unsure, say N.
config SDH_BFIN_MISSING_CMD_PULLUP_WORKAROUND
- bool "Blackfin EZkit Missing SDH_CMD Pull Up Resistor Workaround"
- depends on SDH_BFIN
- help
- If you say yes here SD-Cards may work on the EZkit.
+ bool "Blackfin EZkit Missing SDH_CMD Pull Up Resistor Workaround"
+ depends on SDH_BFIN
+ help
+ If you say yes here SD-Cards may work on the EZkit.
diff -puN drivers/mmc/host/Makefile~blackfin-sd-host-controller-driver-fix drivers/mmc/host/Makefile
diff -puN drivers/mmc/host/bfin_sdh.c~blackfin-sd-host-controller-driver-fix drivers/mmc/host/bfin_sdh.c
--- a/drivers/mmc/host/bfin_sdh.c~blackfin-sd-host-controller-driver-fix
+++ a/drivers/mmc/host/bfin_sdh.c
@@ -53,7 +53,7 @@ struct dma_desc_array {
unsigned short cfg;
unsigned short x_count;
short x_modify;
-} __attribute__((packed));
+} __packed;
struct sdh_host {
struct mmc_host *mmc;
@@ -149,15 +149,17 @@ static int sdh_setup_data(struct sdh_hos
sdh_enable_stat_irq(host, (DAT_CRC_FAIL | DAT_TIME_OUT | DAT_END));
host->dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len, host->dma_dir);
#if defined(CONFIG_BF54x)
- int i;
dma_cfg |= DMAFLOW_ARRAY | NDSIZE_5 | RESTART | WDSIZE_32 | DMAEN;
- for_each_sg(data->sg, sg, host->dma_len, i) {
- host->sg_cpu[i].start_addr = sg_dma_address(sg);
- host->sg_cpu[i].cfg = dma_cfg;
- host->sg_cpu[i].x_count = sg_dma_len(sg) / 4;
- host->sg_cpu[i].x_modify = 4;
- dev_dbg(mmc_dev(host->mmc), "%d: start_addr:0x%lx, cfg:0x%x, x_count:0x%x,\
- x_modify:0x%x\n", i, host->sg_cpu[i].start_addr,
+ {
+ int i;
+ for_each_sg(data->sg, sg, host->dma_len, i) {
+ host->sg_cpu[i].start_addr = sg_dma_address(sg);
+ host->sg_cpu[i].cfg = dma_cfg;
+ host->sg_cpu[i].x_count = sg_dma_len(sg) / 4;
+ host->sg_cpu[i].x_modify = 4;
+ dev_dbg(mmc_dev(host->mmc), "%d: start_addr:0x%lx, "
+ "cfg:0x%x, x_count:0x%x, x_modify:0x%x\n",
+ i, host->sg_cpu[i].start_addr,
host->sg_cpu[i].cfg, host->sg_cpu[i].x_count,
host->sg_cpu[i].x_modify);
}
@@ -205,8 +207,9 @@ static void sdh_start_cmd(struct sdh_hos
if (cmd->flags & MMC_RSP_PRESENT) {
sdh_cmd |= CMD_RSP;
stat_mask |= CMD_RESP_END;
- } else
+ } else {
stat_mask |= CMD_SENT;
+ }
if (cmd->flags & MMC_RSP_136)
sdh_cmd |= CMD_L_RSP;
@@ -304,8 +307,9 @@ static int sdh_data_done(struct sdh_host
if (host->mrq->stop) {
sdh_stop_clock(host);
sdh_start_cmd(host, host->mrq->stop);
- } else
+ } else }
sdh_finish_request(host, host->mrq);
+ }
return 1;
}
@@ -425,7 +429,7 @@ static irqreturn_t sdh_stat_irq(int irq,
status = bfin_read_SDH_STATUS();
if (status & (CMD_SENT | CMD_RESP_END | CMD_TIME_OUT | CMD_CRC_FAIL)) {
handled |= sdh_cmd_done(host, status);
- bfin_write_SDH_STATUS_CLR( CMD_SENT_STAT | CMD_RESP_END_STAT | \
+ bfin_write_SDH_STATUS_CLR(CMD_SENT_STAT | CMD_RESP_END_STAT | \
CMD_TIMEOUT_STAT | CMD_CRC_FAIL_STAT);
SSYNC();
}
_
--
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