From: Andrew Jeffery <andrew@aj.id.au>
To: linux-mmc@vger.kernel.org
Cc: Andrew Jeffery <andrew@aj.id.au>,
adrian.hunter@intel.com, ulf.hansson@linaro.org, joel@jms.id.au,
openbmc@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org,
linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2 4/4] mmc: sdhci-of-aspeed: Allow max-frequency limitation of SDCLK
Date: Mon, 2 Sep 2019 13:28:42 +0930 [thread overview]
Message-ID: <20190902035842.2747-5-andrew@aj.id.au> (raw)
In-Reply-To: <20190902035842.2747-1-andrew@aj.id.au>
Add a get_max_clock() handler to sdhci-of-aspeed to report f_max as the
maximum clock rate if it is set. This enables artificial limitation of
the bus speed via max-frequency in the devicetree for e.g. the AST2600
evaluation board where I was seeing errors at 200MHz.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
drivers/mmc/host/sdhci-of-aspeed.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c
index c31d74427c49..a8a5341b526c 100644
--- a/drivers/mmc/host/sdhci-of-aspeed.c
+++ b/drivers/mmc/host/sdhci-of-aspeed.c
@@ -52,16 +52,24 @@ static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc,
static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
+ struct sdhci_pltfm_host *pltfm_host;
+ unsigned long parent;
int div;
u16 clk;
+ pltfm_host = sdhci_priv(host);
+ parent = clk_get_rate(pltfm_host->clk);
+
sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
if (clock == 0)
return;
+ if (WARN_ON(clock > host->max_clk))
+ clock = host->max_clk;
+
for (div = 1; div < 256; div *= 2) {
- if ((host->max_clk / div) <= clock)
+ if ((parent / div) <= clock)
break;
}
div >>= 1;
@@ -71,6 +79,14 @@ static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
sdhci_enable_clk(host, clk);
}
+static unsigned int aspeed_sdhci_get_max_clock(struct sdhci_host *host)
+{
+ if (host->mmc->f_max)
+ return host->mmc->f_max;
+
+ return sdhci_pltfm_clk_get_max_clock(host);
+}
+
static void aspeed_sdhci_set_bus_width(struct sdhci_host *host, int width)
{
struct sdhci_pltfm_host *pltfm_priv;
@@ -97,7 +113,7 @@ static void aspeed_sdhci_set_bus_width(struct sdhci_host *host, int width)
static const struct sdhci_ops aspeed_sdhci_ops = {
.set_clock = aspeed_sdhci_set_clock,
- .get_max_clock = sdhci_pltfm_clk_get_max_clock,
+ .get_max_clock = aspeed_sdhci_get_max_clock,
.set_bus_width = aspeed_sdhci_set_bus_width,
.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
.reset = sdhci_reset,
--
2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Jeffery <andrew@aj.id.au>
To: linux-mmc@vger.kernel.org
Cc: ulf.hansson@linaro.org, linux-aspeed@lists.ozlabs.org,
Andrew Jeffery <andrew@aj.id.au>,
openbmc@lists.ozlabs.org, adrian.hunter@intel.com,
linux-kernel@vger.kernel.org, joel@jms.id.au,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 4/4] mmc: sdhci-of-aspeed: Allow max-frequency limitation of SDCLK
Date: Mon, 2 Sep 2019 13:28:42 +0930 [thread overview]
Message-ID: <20190902035842.2747-5-andrew@aj.id.au> (raw)
In-Reply-To: <20190902035842.2747-1-andrew@aj.id.au>
Add a get_max_clock() handler to sdhci-of-aspeed to report f_max as the
maximum clock rate if it is set. This enables artificial limitation of
the bus speed via max-frequency in the devicetree for e.g. the AST2600
evaluation board where I was seeing errors at 200MHz.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
---
drivers/mmc/host/sdhci-of-aspeed.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci-of-aspeed.c b/drivers/mmc/host/sdhci-of-aspeed.c
index c31d74427c49..a8a5341b526c 100644
--- a/drivers/mmc/host/sdhci-of-aspeed.c
+++ b/drivers/mmc/host/sdhci-of-aspeed.c
@@ -52,16 +52,24 @@ static void aspeed_sdc_configure_8bit_mode(struct aspeed_sdc *sdc,
static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
+ struct sdhci_pltfm_host *pltfm_host;
+ unsigned long parent;
int div;
u16 clk;
+ pltfm_host = sdhci_priv(host);
+ parent = clk_get_rate(pltfm_host->clk);
+
sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
if (clock == 0)
return;
+ if (WARN_ON(clock > host->max_clk))
+ clock = host->max_clk;
+
for (div = 1; div < 256; div *= 2) {
- if ((host->max_clk / div) <= clock)
+ if ((parent / div) <= clock)
break;
}
div >>= 1;
@@ -71,6 +79,14 @@ static void aspeed_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
sdhci_enable_clk(host, clk);
}
+static unsigned int aspeed_sdhci_get_max_clock(struct sdhci_host *host)
+{
+ if (host->mmc->f_max)
+ return host->mmc->f_max;
+
+ return sdhci_pltfm_clk_get_max_clock(host);
+}
+
static void aspeed_sdhci_set_bus_width(struct sdhci_host *host, int width)
{
struct sdhci_pltfm_host *pltfm_priv;
@@ -97,7 +113,7 @@ static void aspeed_sdhci_set_bus_width(struct sdhci_host *host, int width)
static const struct sdhci_ops aspeed_sdhci_ops = {
.set_clock = aspeed_sdhci_set_clock,
- .get_max_clock = sdhci_pltfm_clk_get_max_clock,
+ .get_max_clock = aspeed_sdhci_get_max_clock,
.set_bus_width = aspeed_sdhci_set_bus_width,
.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
.reset = sdhci_reset,
--
2.20.1
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next prev parent reply other threads:[~2019-09-02 3:58 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-02 3:58 [PATCH v2 0/4] mmc: sdhci-of-aspeed: Fixes for AST2600 eMMC support Andrew Jeffery
2019-09-02 3:58 ` Andrew Jeffery
2019-09-02 3:58 ` [PATCH v2 1/4] mmc: sdhci-of-aspeed: Fix link failure for SPARC Andrew Jeffery
2019-09-02 3:58 ` Andrew Jeffery
2019-09-02 4:12 ` Joel Stanley
2019-09-02 4:12 ` Joel Stanley
2019-09-02 4:12 ` Joel Stanley
2019-09-02 5:26 ` Andrew Jeffery
2019-09-02 5:26 ` Andrew Jeffery
2019-09-03 14:48 ` Ulf Hansson
2019-09-03 14:48 ` Ulf Hansson
2019-09-03 14:48 ` Ulf Hansson
2019-09-04 0:02 ` Andrew Jeffery
2019-09-04 0:02 ` Andrew Jeffery
2019-09-02 3:58 ` [PATCH v2 2/4] mmc: sdhci-of-aspeed: Drop redundant assignment to host->clock Andrew Jeffery
2019-09-02 3:58 ` Andrew Jeffery
2019-09-02 3:58 ` [PATCH v2 3/4] mmc: sdhci-of-aspeed: Uphold clocks-on post-condition of set_clock() Andrew Jeffery
2019-09-02 3:58 ` Andrew Jeffery
2019-09-02 3:58 ` Andrew Jeffery [this message]
2019-09-02 3:58 ` [PATCH v2 4/4] mmc: sdhci-of-aspeed: Allow max-frequency limitation of SDCLK Andrew Jeffery
2019-09-03 15:10 ` [PATCH v2 0/4] mmc: sdhci-of-aspeed: Fixes for AST2600 eMMC support Ulf Hansson
2019-09-03 15:10 ` Ulf Hansson
2019-09-03 15:10 ` Ulf Hansson
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