Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
On 08/27/2014 01:32 AM, Tomeu Vizoso wrote: On 08/26/2014 07:17 PM, Stephen Warren wrote: On 08/26/2014 07:12 AM, Tomeu Vizoso wrote: Sets the EMC clock rate based on the bandwidth requirements registered by memory clients through the PM_QOS_MEMORY_BANDWIDTH class. Note: this is just an example and not a proper driver for a external memory controller. Its only purpose is to illustrate how such a driver would set the frequency of the external memory clock based on the bandwidth requirements of memory clients. diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c @@ -112,6 +117,11 @@ static void __init tegra_dt_init(void) parent = soc_device_to_device(soc_dev); /* + * HACK: register a platform device to probe the driver + */ +platform_device_register(_emc); I don't think this is a hack, except for the bug: That should only happen on Tegra124 not on all Tegra SoCs. Do you intend all 3 patches in this series to be merged? You'd mentioned you didn't when asked about this for a previous version. I'm not sure if that's changed? Yeah, I don't want 3/3 merged because we don't have a functional EMC clock yet on T124, and because I don't know yet where will be the best place to have that code in. That depends on Mikko's work on the real EMC driver which is in a bit of flux right now. I have kept posting it just because I think it complements nicely the explanation in the cover letter, but maybe confuses more than helps. OK. If you make this one a [PATCH RFC], or add a note to that effect to the commit description (perhaps underneath the --- line), that'd be helpful for future postings. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
On 08/26/2014 07:17 PM, Stephen Warren wrote: On 08/26/2014 07:12 AM, Tomeu Vizoso wrote: Sets the EMC clock rate based on the bandwidth requirements registered by memory clients through the PM_QOS_MEMORY_BANDWIDTH class. Note: this is just an example and not a proper driver for a external memory controller. Its only purpose is to illustrate how such a driver would set the frequency of the external memory clock based on the bandwidth requirements of memory clients. diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c @@ -112,6 +117,11 @@ static void __init tegra_dt_init(void) parent = soc_device_to_device(soc_dev); /* + * HACK: register a platform device to probe the driver + */ +platform_device_register(_emc); I don't think this is a hack, except for the bug: That should only happen on Tegra124 not on all Tegra SoCs. Do you intend all 3 patches in this series to be merged? You'd mentioned you didn't when asked about this for a previous version. I'm not sure if that's changed? Yeah, I don't want 3/3 merged because we don't have a functional EMC clock yet on T124, and because I don't know yet where will be the best place to have that code in. That depends on Mikko's work on the real EMC driver which is in a bit of flux right now. I have kept posting it just because I think it complements nicely the explanation in the cover letter, but maybe confuses more than helps. Regards, Tomeu To merge, I'd need Thierry's ack on patch 2, and Thierry's, Peter's, Mikko's, and/or Tuomas's on this patch. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
On 08/26/2014 07:17 PM, Stephen Warren wrote: On 08/26/2014 07:12 AM, Tomeu Vizoso wrote: Sets the EMC clock rate based on the bandwidth requirements registered by memory clients through the PM_QOS_MEMORY_BANDWIDTH class. Note: this is just an example and not a proper driver for a external memory controller. Its only purpose is to illustrate how such a driver would set the frequency of the external memory clock based on the bandwidth requirements of memory clients. diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c @@ -112,6 +117,11 @@ static void __init tegra_dt_init(void) parent = soc_device_to_device(soc_dev); /* + * HACK: register a platform device to probe the driver + */ +platform_device_register(tegra_emc); I don't think this is a hack, except for the bug: That should only happen on Tegra124 not on all Tegra SoCs. Do you intend all 3 patches in this series to be merged? You'd mentioned you didn't when asked about this for a previous version. I'm not sure if that's changed? Yeah, I don't want 3/3 merged because we don't have a functional EMC clock yet on T124, and because I don't know yet where will be the best place to have that code in. That depends on Mikko's work on the real EMC driver which is in a bit of flux right now. I have kept posting it just because I think it complements nicely the explanation in the cover letter, but maybe confuses more than helps. Regards, Tomeu To merge, I'd need Thierry's ack on patch 2, and Thierry's, Peter's, Mikko's, and/or Tuomas's on this patch. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
On 08/27/2014 01:32 AM, Tomeu Vizoso wrote: On 08/26/2014 07:17 PM, Stephen Warren wrote: On 08/26/2014 07:12 AM, Tomeu Vizoso wrote: Sets the EMC clock rate based on the bandwidth requirements registered by memory clients through the PM_QOS_MEMORY_BANDWIDTH class. Note: this is just an example and not a proper driver for a external memory controller. Its only purpose is to illustrate how such a driver would set the frequency of the external memory clock based on the bandwidth requirements of memory clients. diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c @@ -112,6 +117,11 @@ static void __init tegra_dt_init(void) parent = soc_device_to_device(soc_dev); /* + * HACK: register a platform device to probe the driver + */ +platform_device_register(tegra_emc); I don't think this is a hack, except for the bug: That should only happen on Tegra124 not on all Tegra SoCs. Do you intend all 3 patches in this series to be merged? You'd mentioned you didn't when asked about this for a previous version. I'm not sure if that's changed? Yeah, I don't want 3/3 merged because we don't have a functional EMC clock yet on T124, and because I don't know yet where will be the best place to have that code in. That depends on Mikko's work on the real EMC driver which is in a bit of flux right now. I have kept posting it just because I think it complements nicely the explanation in the cover letter, but maybe confuses more than helps. OK. If you make this one a [PATCH RFC], or add a note to that effect to the commit description (perhaps underneath the --- line), that'd be helpful for future postings. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
On 08/26/2014 07:12 AM, Tomeu Vizoso wrote: Sets the EMC clock rate based on the bandwidth requirements registered by memory clients through the PM_QOS_MEMORY_BANDWIDTH class. Note: this is just an example and not a proper driver for a external memory controller. Its only purpose is to illustrate how such a driver would set the frequency of the external memory clock based on the bandwidth requirements of memory clients. diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c @@ -112,6 +117,11 @@ static void __init tegra_dt_init(void) parent = soc_device_to_device(soc_dev); /* +* HACK: register a platform device to probe the driver +*/ + platform_device_register(_emc); I don't think this is a hack, except for the bug: That should only happen on Tegra124 not on all Tegra SoCs. Do you intend all 3 patches in this series to be merged? You'd mentioned you didn't when asked about this for a previous version. I'm not sure if that's changed? To merge, I'd need Thierry's ack on patch 2, and Thierry's, Peter's, Mikko's, and/or Tuomas's on this patch. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
Sets the EMC clock rate based on the bandwidth requirements registered by
memory clients through the PM_QOS_MEMORY_BANDWIDTH class.
Note: this is just an example and not a proper driver for a external memory
controller. Its only purpose is to illustrate how such a driver would set the
frequency of the external memory clock based on the bandwidth requirements of
memory clients.
---
v4: * Add hack so the driver gets actually registered.
* Use the tegra-clk-debug dev_id to query the EMC clock
* Get units right and use types consistently
---
arch/arm/mach-tegra/tegra.c | 10
drivers/memory/Kconfig| 9
drivers/memory/Makefile | 1 +
drivers/memory/tegra124-emc.c | 117 ++
4 files changed, 137 insertions(+)
create mode 100644 drivers/memory/tegra124-emc.c
diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index 5ef5173..099d8e7f 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -70,6 +70,11 @@ u32 tegra_uart_config[3] = {
0,
};
+static struct platform_device tegra_emc = {
+ .name = "tegra124-emc",
+ .id = -1,
+};
+
static void __init tegra_init_early(void)
{
of_register_trusted_foundations();
@@ -112,6 +117,11 @@ static void __init tegra_dt_init(void)
parent = soc_device_to_device(soc_dev);
/*
+* HACK: register a platform device to probe the driver
+*/
+ platform_device_register(_emc);
+
+ /*
* Finished with the static registrations now; fill in the missing
* devices
*/
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index fab81a1..2088b2b 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -61,6 +61,15 @@ config TEGRA30_MC
analysis, especially for IOMMU/SMMU(System Memory Management
Unit) module.
+config TEGRA124_EMC
+ tristate "Tegra124 External Memory Controller (EMC) driver"
+ default y
+ depends on ARCH_TEGRA_124_SOC
+ help
+ This driver is for the External Memory Controller (EMC) module
+ available in Tegra124 SoCs.
+
+
config FSL_CORENET_CF
tristate "Freescale CoreNet Error Reporting"
depends on FSL_SOC_BOOKE
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 4055c47..0a6d117 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_FSL_IFC) += fsl_ifc.o
obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o
obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
obj-$(CONFIG_TEGRA30_MC) += tegra30-mc.o
+obj-$(CONFIG_TEGRA124_EMC) += tegra124-emc.o
diff --git a/drivers/memory/tegra124-emc.c b/drivers/memory/tegra124-emc.c
new file mode 100644
index 000..a290ad5
--- /dev/null
+++ b/drivers/memory/tegra124-emc.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see
[PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
Sets the EMC clock rate based on the bandwidth requirements registered by
memory clients through the PM_QOS_MEMORY_BANDWIDTH class.
Note: this is just an example and not a proper driver for a external memory
controller. Its only purpose is to illustrate how such a driver would set the
frequency of the external memory clock based on the bandwidth requirements of
memory clients.
---
v4: * Add hack so the driver gets actually registered.
* Use the tegra-clk-debug dev_id to query the EMC clock
* Get units right and use types consistently
---
arch/arm/mach-tegra/tegra.c | 10
drivers/memory/Kconfig| 9
drivers/memory/Makefile | 1 +
drivers/memory/tegra124-emc.c | 117 ++
4 files changed, 137 insertions(+)
create mode 100644 drivers/memory/tegra124-emc.c
diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c
index 5ef5173..099d8e7f 100644
--- a/arch/arm/mach-tegra/tegra.c
+++ b/arch/arm/mach-tegra/tegra.c
@@ -70,6 +70,11 @@ u32 tegra_uart_config[3] = {
0,
};
+static struct platform_device tegra_emc = {
+ .name = tegra124-emc,
+ .id = -1,
+};
+
static void __init tegra_init_early(void)
{
of_register_trusted_foundations();
@@ -112,6 +117,11 @@ static void __init tegra_dt_init(void)
parent = soc_device_to_device(soc_dev);
/*
+* HACK: register a platform device to probe the driver
+*/
+ platform_device_register(tegra_emc);
+
+ /*
* Finished with the static registrations now; fill in the missing
* devices
*/
diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index fab81a1..2088b2b 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -61,6 +61,15 @@ config TEGRA30_MC
analysis, especially for IOMMU/SMMU(System Memory Management
Unit) module.
+config TEGRA124_EMC
+ tristate Tegra124 External Memory Controller (EMC) driver
+ default y
+ depends on ARCH_TEGRA_124_SOC
+ help
+ This driver is for the External Memory Controller (EMC) module
+ available in Tegra124 SoCs.
+
+
config FSL_CORENET_CF
tristate Freescale CoreNet Error Reporting
depends on FSL_SOC_BOOKE
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 4055c47..0a6d117 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_FSL_IFC) += fsl_ifc.o
obj-$(CONFIG_MVEBU_DEVBUS) += mvebu-devbus.o
obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
obj-$(CONFIG_TEGRA30_MC) += tegra30-mc.o
+obj-$(CONFIG_TEGRA124_EMC) += tegra124-emc.o
diff --git a/drivers/memory/tegra124-emc.c b/drivers/memory/tegra124-emc.c
new file mode 100644
index 000..a290ad5
--- /dev/null
+++ b/drivers/memory/tegra124-emc.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2013, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see http://www.gnu.org/licenses/.
+ */
+
+#include linux/clk.h
+#include linux/kernel.h
+#include linux/module.h
+#include linux/platform_device.h
+#include linux/pm_qos.h
+
+#define DRV_NAME tegra124-emc
+#define EMC_FREQ_CUTOFF_USE_130_PERCENT1
+#define EMC_FREQ_CUTOFF_USE_140_PERCENT5000
+#define BYTES_PER_EMC_CLOCK 16
+
+struct tegra124_emc {
+ struct clk *clk;
+ struct notifier_block memory_bw_notifier;
+};
+
+static struct platform_device *emc_pdev;
+
+static unsigned long tegra124_emc_bw_to_freq_req(s32 bw)
+{
+ return (bw * 8 + BYTES_PER_EMC_CLOCK - 1) / BYTES_PER_EMC_CLOCK;
+}
+
+static void tegra124_emc_update_rate(struct tegra124_emc *emc, s32
total_bandwidth)
+{
+ struct clk *emc_master;
+ unsigned long freq;
+
+ emc_master = clk_get_parent(emc-clk);
+ freq = tegra124_emc_bw_to_freq_req(total_bandwidth * 1024);
+ freq = clk_round_rate(emc_master, freq);
+
+ /* Depending on frequency value, the amount of bandwidth usage % of
+* total we should use is different. Thus we should request a multiple
of
+* original bandwidth on this. Use 1.4 for 50MHz, 1.3 for 100MHz,
+* else 1.1 */
+ if (freq EMC_FREQ_CUTOFF_USE_140_PERCENT)
+ total_bandwidth += 4 * total_bandwidth / 10; /* 1.4 */
+ else if (freq EMC_FREQ_CUTOFF_USE_130_PERCENT)
+ total_bandwidth += 3 * total_bandwidth / 10; /* 1.3
Re: [PATCH v4 3/3] memory: tegra124-emc: Add EMC driver
On 08/26/2014 07:12 AM, Tomeu Vizoso wrote: Sets the EMC clock rate based on the bandwidth requirements registered by memory clients through the PM_QOS_MEMORY_BANDWIDTH class. Note: this is just an example and not a proper driver for a external memory controller. Its only purpose is to illustrate how such a driver would set the frequency of the external memory clock based on the bandwidth requirements of memory clients. diff --git a/arch/arm/mach-tegra/tegra.c b/arch/arm/mach-tegra/tegra.c @@ -112,6 +117,11 @@ static void __init tegra_dt_init(void) parent = soc_device_to_device(soc_dev); /* +* HACK: register a platform device to probe the driver +*/ + platform_device_register(tegra_emc); I don't think this is a hack, except for the bug: That should only happen on Tegra124 not on all Tegra SoCs. Do you intend all 3 patches in this series to be merged? You'd mentioned you didn't when asked about this for a previous version. I'm not sure if that's changed? To merge, I'd need Thierry's ack on patch 2, and Thierry's, Peter's, Mikko's, and/or Tuomas's on this patch. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
