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Revert "bcm2835-sdhost: Precalc divisors and overclocks"

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This reverts commit 2026046277.
This commit is contained in:
Phil Elwell
2016-04-04 12:35:32 +01:00
parent 2026046277
commit 9524a87ecc
1 changed files with 60 additions and 84 deletions
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144
drivers/mmc/host/bcm2835-sdhost.c
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@@ -154,15 +154,12 @@ struct bcm2835_host {
u32 pio_timeout; /* In jiffies */
int clock; /* Current clock speed */
int clocks[2];
bool slow_card; /* Force 11-bit divisor */
unsigned int max_clk; /* Max src clock freq */
unsigned int src_clks[2]; /* Min/max src clock freqs */
unsigned int cur_clk_idx; /* Index of current clock */
unsigned int next_clk_idx; /* Next clock index */
unsigned int cdivs[2];
unsigned int min_clk; /* Min src clock freq */
unsigned int cur_clk; /* Current src clock freq */
struct tasklet_struct finish_tasklet; /* Tasklet structures */
@@ -216,7 +213,7 @@ struct bcm2835_host {
u32 delay_after_stop; /* minimum time between stop and subsequent data transfer */
u32 delay_after_this_stop; /* minimum time between this stop and subsequent data transfer */
u32 overclock_50; /* frequency to use when 50MHz is requested (in MHz) */
u32 prev_overclock_50;
u32 overclock; /* Current frequency if overclocked, else zero */
u32 pio_limit; /* Maximum block count for PIO (0 = always DMA) */
u32 sectors; /* Cached card size in sectors */
@@ -1512,35 +1509,10 @@ static irqreturn_t bcm2835_sdhost_irq(int irq, void *dev_id)
return result;
}
static void bcm2835_sdhost_select_clock(struct bcm2835_host *host, int idx)
{
unsigned int clock = host->clocks[idx];
unsigned int cdiv = host->cdivs[idx];
host->mmc->actual_clock = clock;
host->ns_per_fifo_word = (1000000000/clock) *
((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
host->cdiv = cdiv;
bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
/* Set the timeout to 500ms */
bcm2835_sdhost_write(host, clock/2, SDTOUT);
host->cur_clk_idx = host->next_clk_idx = idx;
if (host->debug)
pr_info("%s: clock=%d -> src_clk=%d, cdiv=%x (actual %d)\n",
mmc_hostname(host->mmc), host->clock,
host->src_clks[idx], host->cdiv,
host->mmc->actual_clock);
}
void bcm2835_sdhost_set_clock(struct bcm2835_host *host)
{
int div = 0; /* Initialized for compiler warning */
unsigned int clock = host->clock;
int clk_idx;
if (host->debug)
pr_info("%s: set_clock(%d)\n", mmc_hostname(host->mmc), clock);
@@ -1581,45 +1553,53 @@ void bcm2835_sdhost_set_clock(struct bcm2835_host *host)
return;
}
/* Calculate the clock divisors */
for (clk_idx = 0; clk_idx <= host->variable_clock; clk_idx++)
{
unsigned int cur_clk = host->src_clks[clk_idx];
unsigned int actual_clock;
div = host->cur_clk / clock;
if (div < 2)
div = 2;
if ((host->cur_clk / div) > clock)
div++;
div -= 2;
div = cur_clk / clock;
if (div < 2)
div = 2;
if ((cur_clk / div) > clock)
div++;
div -= 2;
if (div > SDCDIV_MAX_CDIV)
div = SDCDIV_MAX_CDIV;
if (div > SDCDIV_MAX_CDIV)
div = SDCDIV_MAX_CDIV;
actual_clock = cur_clk / (div + 2);
clock = host->cur_clk / (div + 2);
host->mmc->actual_clock = clock;
host->cdivs[clk_idx] = div;
host->clocks[clk_idx] = actual_clock;
/* Calibrate some delays */
if (host->overclock_50 != host->prev_overclock_50) {
const char *clk_name = "";
if (host->variable_clock)
clk_name = clk_idx ? " (turbo)" : " (normal)";
if (actual_clock > host->clock)
pr_info("%s: overclocking to %dHz%s\n",
mmc_hostname(host->mmc),
actual_clock, clk_name);
else if ((host->overclock_50 < 50) && (clk_idx == 0))
pr_info("%s: cancelling overclock%s\n",
mmc_hostname(host->mmc),
host->variable_clock ? "s" : "");
host->ns_per_fifo_word = (1000000000/clock) *
((host->mmc->caps & MMC_CAP_4_BIT_DATA) ? 8 : 32);
if (clock > host->clock) {
/* Save the closest value, to make it easier
to reduce in the event of error */
host->overclock_50 = (clock/MHZ);
if (clock != host->overclock) {
pr_warn("%s: overclocking to %dHz\n",
mmc_hostname(host->mmc), clock);
host->overclock = clock;
}
}
else if (host->overclock)
{
host->overclock = 0;
if (clock == 50 * MHZ)
pr_warn("%s: cancelling overclock\n",
mmc_hostname(host->mmc));
}
if (host->clock == 50*MHZ)
host->prev_overclock_50 = host->overclock_50;
host->cdiv = div;
bcm2835_sdhost_write(host, host->cdiv, SDCDIV);
bcm2835_sdhost_select_clock(host, host->cur_clk_idx);
/* Set the timeout to 500ms */
bcm2835_sdhost_write(host, host->mmc->actual_clock/2, SDTOUT);
if (host->debug)
pr_info("%s: clock=%d -> cur_clk=%d, cdiv=%x (actual clock %d)\n",
mmc_hostname(host->mmc), host->clock,
host->cur_clk, host->cdiv, host->mmc->actual_clock);
}
static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq)
@@ -1677,9 +1657,6 @@ static void bcm2835_sdhost_request(struct mmc_host *mmc, struct mmc_request *mrq
spin_lock_irqsave(&host->lock, flags);
if (host->next_clk_idx != host->cur_clk_idx)
bcm2835_sdhost_select_clock(host, host->next_clk_idx);
WARN_ON(host->mrq != NULL);
host->mrq = mrq;
@@ -1742,7 +1719,11 @@ static int bcm2835_sdhost_cpufreq_callback(struct notifier_block *nb,
return NOTIFY_BAD;
break;
case CPUFREQ_POSTCHANGE:
host->next_clk_idx = (freq->new > freq->old);
if (freq->new > freq->old)
host->cur_clk = host->max_clk;
else
host->cur_clk = host->min_clk;
bcm2835_sdhost_set_clock(host);
up(&host->cpufreq_semaphore);
break;
default:
@@ -1782,11 +1763,8 @@ static void bcm2835_sdhost_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
ios->clock, ios->power_mode, ios->bus_width,
ios->timing, ios->signal_voltage, ios->drv_type);
if (ios->clock && (host->cur_clk_idx == -1)) {
unsigned int cur_clk =
get_core_clock(RPI_FIRMWARE_GET_CLOCK_RATE);
host->cur_clk_idx = (cur_clk == host->src_clks[0]) ? 0 : 1;
}
if (ios->clock && !host->cur_clk)
host->cur_clk = get_core_clock(RPI_FIRMWARE_GET_CLOCK_RATE);
spin_lock_irqsave(&host->lock, flags);
@@ -1876,12 +1854,11 @@ static void bcm2835_sdhost_tasklet_finish(unsigned long param)
/* Drop the overclock after any data corruption, or after any
error overclocked */
if (host->clock > 50*MHZ) {
if (host->overclock) {
if ((mrq->cmd && mrq->cmd->error) ||
(mrq->data && mrq->data->error) ||
(mrq->stop && mrq->stop->error)) {
host->overclock_50 = (host->clock/MHZ) - 1;
host->overclock_50--;
pr_warn("%s: reducing overclock due to errors\n",
mmc_hostname(host->mmc));
bcm2835_sdhost_set_clock(host);
@@ -2045,7 +2022,7 @@ static int bcm2835_sdhost_probe(struct platform_device *pdev)
struct bcm2835_host *host;
struct mmc_host *mmc;
const __be32 *addr;
unsigned int max_clk, min_clk;
unsigned int max_clk;
int ret;
pr_debug("bcm2835_sdhost_probe\n");
@@ -2151,8 +2128,12 @@ static int bcm2835_sdhost_probe(struct platform_device *pdev)
else
mmc->caps |= MMC_CAP_4_BIT_DATA;
ret = bcm2835_sdhost_add_host(host);
if (ret)
goto err;
/* Query the core clock frequencies */
min_clk = get_core_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE);
host->min_clk = get_core_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE);
max_clk = get_core_clock(RPI_FIRMWARE_GET_MAX_CLOCK_RATE);
if (max_clk != host->max_clk) {
pr_warn("%s: Expected max clock %d, found %d\n",
@@ -2160,24 +2141,19 @@ static int bcm2835_sdhost_probe(struct platform_device *pdev)
host->max_clk = max_clk;
}
host->src_clks[0] = min_clk;
host->cur_clk_idx = -1;
if (max_clk != min_clk) {
host->src_clks[1] = max_clk;
if (host->min_clk != host->max_clk) {
host->cpufreq_nb.notifier_call =
bcm2835_sdhost_cpufreq_callback;
sema_init(&host->cpufreq_semaphore, 1);
cpufreq_register_notifier(&host->cpufreq_nb,
CPUFREQ_TRANSITION_NOTIFIER);
host->variable_clock = 1;
host->cur_clk = 0; /* Get this later */
} else {
host->variable_clock = 0;
host->cur_clk = host->max_clk;
}
ret = bcm2835_sdhost_add_host(host);
if (ret)
goto err;
platform_set_drvdata(pdev, host);
pr_debug("bcm2835_sdhost_probe -> OK\n");