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mmc: msm_sdcc: Wrap readl/writel calls with appropriate clk delays
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As it turns out, all sdcc register writes must be delayed by at
least 3 core clock cycles for the writes to take effect. *sigh*

    Also removes the 30us constant delay on clock enable in favor
of a 3 core clock delay.

Signed-off-by: San Mehat <san@google.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
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San Mehat authored and Daniel Walker committed Mar 18, 2010
1 parent 865c806 commit 8b1c2ba
Showing 1 changed file with 61 additions and 55 deletions.
116 changes: 61 additions & 55 deletions drivers/mmc/host/msm_sdcc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -62,6 +62,7 @@ static inline int
msmsdcc_enable_clocks(struct msmsdcc_host *host, int enable)
{
int rc;

WARN_ON(enable == host->clks_on);
if (enable) {
rc = clk_enable(host->pclk);
Expand All @@ -72,7 +73,8 @@ msmsdcc_enable_clocks(struct msmsdcc_host *host, int enable)
clk_disable(host->pclk);
return rc;
}
udelay(30);
udelay(1 + ((3 * USEC_PER_SEC) /
(host->clk_rate ? host->clk_rate : msmsdcc_fmin)));
host->clks_on = 1;
} else {
clk_disable(host->clk);
Expand All @@ -82,6 +84,20 @@ msmsdcc_enable_clocks(struct msmsdcc_host *host, int enable)
return 0;
}

static inline unsigned int
msmsdcc_readl(struct msmsdcc_host *host, unsigned int reg)
{
return readl(host->base + reg);
}

static inline void
msmsdcc_writel(struct msmsdcc_host *host, u32 data, unsigned int reg)
{
writel(data, host->base + reg);
/* 3 clk delay required! */
udelay(1 + ((3 * USEC_PER_SEC) /
(host->clk_rate ? host->clk_rate : msmsdcc_fmin)));
}

static void
msmsdcc_start_command(struct msmsdcc_host *host, struct mmc_command *cmd,
Expand All @@ -90,7 +106,7 @@ msmsdcc_start_command(struct msmsdcc_host *host, struct mmc_command *cmd,
static void
msmsdcc_request_end(struct msmsdcc_host *host, struct mmc_request *mrq)
{
writel(0, host->base + MMCICOMMAND);
msmsdcc_writel(host, 0, MMCICOMMAND);

BUG_ON(host->curr.data);

Expand All @@ -116,7 +132,7 @@ msmsdcc_request_end(struct msmsdcc_host *host, struct mmc_request *mrq)
static void
msmsdcc_stop_data(struct msmsdcc_host *host)
{
writel(0, host->base + MMCIDATACTRL);
msmsdcc_writel(host, 0, MMCIDATACTRL);
host->curr.data = NULL;
host->curr.got_dataend = host->curr.got_datablkend = 0;
}
Expand Down Expand Up @@ -200,7 +216,7 @@ msmsdcc_dma_complete_func(struct msm_dmov_cmd *cmd,
if (!mrq->data->error)
host->curr.data_xfered = host->curr.xfer_size;
if (!mrq->data->stop || mrq->cmd->error) {
writel(0, host->base + MMCICOMMAND);
msmsdcc_writel(host, 0, MMCICOMMAND);
host->curr.mrq = NULL;
host->curr.cmd = NULL;
mrq->data->bytes_xfered = host->curr.data_xfered;
Expand Down Expand Up @@ -337,7 +353,6 @@ msmsdcc_start_data(struct msmsdcc_host *host, struct mmc_data *data)
{
unsigned int datactrl, timeout;
unsigned long long clks;
void __iomem *base = host->base;
unsigned int pio_irqmask = 0;

host->curr.data = data;
Expand All @@ -352,9 +367,9 @@ msmsdcc_start_data(struct msmsdcc_host *host, struct mmc_data *data)
clks = (unsigned long long)data->timeout_ns * host->clk_rate;
do_div(clks, NSEC_PER_SEC);
timeout = data->timeout_clks + (unsigned int)clks;
writel(timeout, base + MMCIDATATIMER);
msmsdcc_writel(host, timeout, MMCIDATATIMER);

writel(host->curr.xfer_size, base + MMCIDATALENGTH);
msmsdcc_writel(host, host->curr.xfer_size, MMCIDATALENGTH);

datactrl = MCI_DPSM_ENABLE | (data->blksz << 4);

Expand All @@ -376,8 +391,8 @@ msmsdcc_start_data(struct msmsdcc_host *host, struct mmc_data *data)
if (data->flags & MMC_DATA_READ)
datactrl |= MCI_DPSM_DIRECTION;

writel(pio_irqmask, base + MMCIMASK1);
writel(datactrl, base + MMCIDATACTRL);
msmsdcc_writel(host, pio_irqmask, MMCIMASK1);
msmsdcc_writel(host, datactrl, MMCIDATACTRL);

if (datactrl & MCI_DPSM_DMAENABLE) {
host->dma.busy = 1;
Expand All @@ -398,12 +413,8 @@ snoop_cccr_abort(struct mmc_command *cmd)
static void
msmsdcc_start_command(struct msmsdcc_host *host, struct mmc_command *cmd, u32 c)
{
void __iomem *base = host->base;

if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
writel(0, base + MMCICOMMAND);
udelay(2 + ((5 * 1000000) / host->clk_rate));
}
if (msmsdcc_readl(host, MMCICOMMAND) & MCI_CPSM_ENABLE)
msmsdcc_writel(host, 0, MMCICOMMAND);

c |= cmd->opcode | MCI_CPSM_ENABLE;

Expand All @@ -428,8 +439,8 @@ msmsdcc_start_command(struct msmsdcc_host *host, struct mmc_command *cmd, u32 c)

host->stats.cmds++;

writel(cmd->arg, base + MMCIARGUMENT);
writel(c, base + MMCICOMMAND);
msmsdcc_writel(host, cmd->arg, MMCIARGUMENT);
msmsdcc_writel(host, c, MMCICOMMAND);
}

static void
Expand Down Expand Up @@ -463,13 +474,11 @@ msmsdcc_data_err(struct msmsdcc_host *host, struct mmc_data *data,
static int
msmsdcc_pio_read(struct msmsdcc_host *host, char *buffer, unsigned int remain)
{
void __iomem *base = host->base;
uint32_t *ptr = (uint32_t *) buffer;
int count = 0;

while (readl(base + MMCISTATUS) & MCI_RXDATAAVLBL) {

*ptr = readl(base + MMCIFIFO + (count % MCI_FIFOSIZE));
while (msmsdcc_readl(host, MMCISTATUS) & MCI_RXDATAAVLBL) {
*ptr = msmsdcc_readl(host, MMCIFIFO + (count % MCI_FIFOSIZE));
ptr++;
count += sizeof(uint32_t);

Expand Down Expand Up @@ -501,7 +510,7 @@ msmsdcc_pio_write(struct msmsdcc_host *host, char *buffer,
if (remain == 0)
break;

status = readl(base + MMCISTATUS);
status = msmsdcc_readl(host, MMCISTATUS);
} while (status & MCI_TXFIFOHALFEMPTY);

return ptr - buffer;
Expand All @@ -511,7 +520,7 @@ static int
msmsdcc_spin_on_status(struct msmsdcc_host *host, uint32_t mask, int maxspin)
{
while (maxspin) {
if ((readl(host->base + MMCISTATUS) & mask))
if ((msmsdcc_readl(host, MMCISTATUS) & mask))
return 0;
udelay(1);
--maxspin;
Expand All @@ -523,10 +532,9 @@ static int
msmsdcc_pio_irq(int irq, void *dev_id)
{
struct msmsdcc_host *host = dev_id;
void __iomem *base = host->base;
uint32_t status;

status = readl(base + MMCISTATUS);
status = msmsdcc_readl(host, MMCISTATUS);

do {
unsigned long flags;
Expand Down Expand Up @@ -581,28 +589,27 @@ msmsdcc_pio_irq(int irq, void *dev_id)
host->pio.sg_off = 0;
}

status = readl(base + MMCISTATUS);
status = msmsdcc_readl(host, MMCISTATUS);
} while (1);

if (status & MCI_RXACTIVE && host->curr.xfer_remain < MCI_FIFOSIZE)
writel(MCI_RXDATAAVLBLMASK, base + MMCIMASK1);
msmsdcc_writel(host, MCI_RXDATAAVLBLMASK, MMCIMASK1);

if (!host->curr.xfer_remain)
writel(0, base + MMCIMASK1);
msmsdcc_writel(host, 0, MMCIMASK1);

return IRQ_HANDLED;
}

static void msmsdcc_do_cmdirq(struct msmsdcc_host *host, uint32_t status)
{
struct mmc_command *cmd = host->curr.cmd;
void __iomem *base = host->base;

host->curr.cmd = NULL;
cmd->resp[0] = readl(base + MMCIRESPONSE0);
cmd->resp[1] = readl(base + MMCIRESPONSE1);
cmd->resp[2] = readl(base + MMCIRESPONSE2);
cmd->resp[3] = readl(base + MMCIRESPONSE3);
cmd->resp[0] = msmsdcc_readl(host, MMCIRESPONSE0);
cmd->resp[1] = msmsdcc_readl(host, MMCIRESPONSE1);
cmd->resp[2] = msmsdcc_readl(host, MMCIRESPONSE2);
cmd->resp[3] = msmsdcc_readl(host, MMCIRESPONSE3);

del_timer(&host->command_timer);
if (status & MCI_CMDTIMEOUT) {
Expand Down Expand Up @@ -699,10 +706,11 @@ msmsdcc_irq(int irq, void *dev_id)
spin_lock(&host->lock);

do {
status = readl(base + MMCISTATUS);

status &= (readl(base + MMCIMASK0) | MCI_DATABLOCKENDMASK);
writel(status, base + MMCICLEAR);
struct mmc_data *data;
status = msmsdcc_readl(host, MMCISTATUS);
status &= (msmsdcc_readl(host, MMCIMASK0) |
MCI_DATABLOCKENDMASK);
msmsdcc_writel(host, status, MMCICLEAR);

if (status & MCI_SDIOINTR)
status &= ~MCI_SDIOINTR;
Expand Down Expand Up @@ -774,10 +782,11 @@ msmsdcc_request(struct mmc_host *mmc, struct mmc_request *mrq)
if (host->cmdpoll && !msmsdcc_spin_on_status(host,
MCI_CMDRESPEND|MCI_CMDCRCFAIL|MCI_CMDTIMEOUT,
CMD_SPINMAX)) {
uint32_t status = readl(host->base + MMCISTATUS);
uint32_t status = msmsdcc_readl(host, MMCISTATUS);
msmsdcc_do_cmdirq(host, status);
writel(MCI_CMDRESPEND | MCI_CMDCRCFAIL | MCI_CMDTIMEOUT,
host->base + MMCICLEAR);
msmsdcc_writel(host,
MCI_CMDRESPEND | MCI_CMDCRCFAIL | MCI_CMDTIMEOUT,
MMCICLEAR);
host->stats.cmdpoll_hits++;
} else {
host->stats.cmdpoll_misses++;
Expand Down Expand Up @@ -836,11 +845,11 @@ msmsdcc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
pwr |= MCI_OD;

writel(clk, host->base + MMCICLOCK);
msmsdcc_writel(host, clk, MMCICLOCK);

if (host->pwr != pwr) {
host->pwr = pwr;
writel(pwr, host->base + MMCIPOWER);
msmsdcc_writel(host, pwr, MMCIPOWER);
}
if (host->clks_on)
msmsdcc_enable_clocks(host, 0);
Expand All @@ -855,13 +864,13 @@ static void msmsdcc_enable_sdio_irq(struct mmc_host *mmc, int enable)

spin_lock_irqsave(&host->lock, flags);
if (msmsdcc_sdioirq == 1) {
status = readl(host->base + MMCIMASK0);
status = msmsdcc_readl(host, MMCIMASK0);
if (enable)
status |= MCI_SDIOINTOPERMASK;
else
status &= ~MCI_SDIOINTOPERMASK;
host->saved_irq0mask = status;
writel(status, host->base + MMCIMASK0);
msmsdcc_writel(host, status, MMCIMASK0);
}
spin_unlock_irqrestore(&host->lock, flags);
}
Expand Down Expand Up @@ -950,19 +959,16 @@ msmsdcc_command_expired(unsigned long _data)
mrq = host->curr.mrq;

if (!mrq) {
pr_info("%s: Command expiry misfire\n",
mmc_hostname(host->mmc));
spin_unlock_irqrestore(&host->lock, flags);
return;
}

pr_err("%s: Command timeout (%p %p %p %p)\n",
mmc_hostname(host->mmc), mrq, mrq->cmd,
mrq->data, host->dma.sg);
pr_err("%s: Controller lockup detected\n",
mmc_hostname(host->mmc));
mrq->cmd->error = -ETIMEDOUT;
msmsdcc_stop_data(host);

writel(0, host->base + MMCICOMMAND);
msmsdcc_writel(host, 0, MMCICOMMAND);

host->curr.mrq = NULL;
host->curr.cmd = NULL;
Expand Down Expand Up @@ -1143,10 +1149,10 @@ msmsdcc_probe(struct platform_device *pdev)
mmc->max_req_size = 33554432; /* MCI_DATA_LENGTH is 25 bits */
mmc->max_seg_size = mmc->max_req_size;

writel(0, host->base + MMCIMASK0);
writel(0x5e007ff, host->base + MMCICLEAR); /* Add: 1 << 25 */
msmsdcc_writel(host, 0, MMCIMASK0);
msmsdcc_writel(host, 0x5e007ff, MMCICLEAR);

writel(MCI_IRQENABLE, host->base + MMCIMASK0);
msmsdcc_writel(host, MCI_IRQENABLE, MMCIMASK0);
host->saved_irq0mask = MCI_IRQENABLE;

/*
Expand Down Expand Up @@ -1269,7 +1275,7 @@ msmsdcc_suspend(struct platform_device *dev, pm_message_t state)
if (mmc->card && mmc->card->type != MMC_TYPE_SDIO)
rc = mmc_suspend_host(mmc, state);
if (!rc) {
writel(0, host->base + MMCIMASK0);
msmsdcc_writel(host, 0, MMCIMASK0);

if (host->clks_on)
msmsdcc_enable_clocks(host, 0);
Expand All @@ -1292,7 +1298,7 @@ msmsdcc_resume(struct platform_device *dev)
if (!host->clks_on)
msmsdcc_enable_clocks(host, 1);

writel(host->saved_irq0mask, host->base + MMCIMASK0);
msmsdcc_writel(host, host->saved_irq0mask, MMCIMASK0);

spin_unlock_irqrestore(&host->lock, flags);

Expand Down

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