From: ccross@android.com (Colin Cross)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 16/21] ARM: tegra: Add external memory controller driver
Date: Sat, 19 Feb 2011 14:26:05 -0800 [thread overview]
Message-ID: <1298154371-5641-18-git-send-email-ccross@android.com> (raw)
In-Reply-To: <1298154371-5641-1-git-send-email-ccross@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
---
arch/arm/mach-tegra/Kconfig | 4 +
arch/arm/mach-tegra/Makefile | 1 +
arch/arm/mach-tegra/tegra2_emc.c | 172 ++++++++++++++++++++++++++++++++++++++
arch/arm/mach-tegra/tegra2_emc.h | 27 ++++++
4 files changed, 204 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-tegra/tegra2_emc.c
create mode 100644 arch/arm/mach-tegra/tegra2_emc.h
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index 9f4fc6b..42d44c7 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -71,3 +71,7 @@ config TEGRA_SYSTEM_DMA
several Tegra device drivers
endif
+
+config TEGRA_EMC_SCALING_ENABLE
+ bool "Enable scaling the memory frequency"
+ default n
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 23de060..3fe357b 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -9,6 +9,7 @@ obj-y += powergate.o
obj-y += fuse.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += clock.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_clocks.o
+obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += tegra2_emc.o
obj-$(CONFIG_ARCH_TEGRA_2x_SOC) += pinmux-t2-tables.o
obj-$(CONFIG_SMP) += platsmp.o localtimer.o headsmp.o
obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/arm/mach-tegra/tegra2_emc.c b/arch/arm/mach-tegra/tegra2_emc.c
new file mode 100644
index 0000000..bd4fa27
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra2_emc.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ * Colin Cross <ccross@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+
+#include <mach/iomap.h>
+
+#include "tegra2_emc.h"
+
+#ifdef CONFIG_TEGRA_EMC_SCALING_ENABLE
+static bool emc_enable = true;
+#else
+static bool emc_enable;
+#endif
+module_param(emc_enable, bool, 0644);
+
+static void __iomem *emc = IO_ADDRESS(TEGRA_EMC_BASE);
+static const struct tegra_emc_table *tegra_emc_table;
+static int tegra_emc_table_size;
+
+static inline void emc_writel(u32 val, unsigned long addr)
+{
+ writel(val, emc + addr);
+}
+
+static inline u32 emc_readl(unsigned long addr)
+{
+ return readl(emc + addr);
+}
+
+static const unsigned long emc_reg_addr[TEGRA_EMC_NUM_REGS] = {
+ 0x2c, /* RC */
+ 0x30, /* RFC */
+ 0x34, /* RAS */
+ 0x38, /* RP */
+ 0x3c, /* R2W */
+ 0x40, /* W2R */
+ 0x44, /* R2P */
+ 0x48, /* W2P */
+ 0x4c, /* RD_RCD */
+ 0x50, /* WR_RCD */
+ 0x54, /* RRD */
+ 0x58, /* REXT */
+ 0x5c, /* WDV */
+ 0x60, /* QUSE */
+ 0x64, /* QRST */
+ 0x68, /* QSAFE */
+ 0x6c, /* RDV */
+ 0x70, /* REFRESH */
+ 0x74, /* BURST_REFRESH_NUM */
+ 0x78, /* PDEX2WR */
+ 0x7c, /* PDEX2RD */
+ 0x80, /* PCHG2PDEN */
+ 0x84, /* ACT2PDEN */
+ 0x88, /* AR2PDEN */
+ 0x8c, /* RW2PDEN */
+ 0x90, /* TXSR */
+ 0x94, /* TCKE */
+ 0x98, /* TFAW */
+ 0x9c, /* TRPAB */
+ 0xa0, /* TCLKSTABLE */
+ 0xa4, /* TCLKSTOP */
+ 0xa8, /* TREFBW */
+ 0xac, /* QUSE_EXTRA */
+ 0x114, /* FBIO_CFG6 */
+ 0xb0, /* ODT_WRITE */
+ 0xb4, /* ODT_READ */
+ 0x104, /* FBIO_CFG5 */
+ 0x2bc, /* CFG_DIG_DLL */
+ 0x2c0, /* DLL_XFORM_DQS */
+ 0x2c4, /* DLL_XFORM_QUSE */
+ 0x2e0, /* ZCAL_REF_CNT */
+ 0x2e4, /* ZCAL_WAIT_CNT */
+ 0x2a8, /* AUTO_CAL_INTERVAL */
+ 0x2d0, /* CFG_CLKTRIM_0 */
+ 0x2d4, /* CFG_CLKTRIM_1 */
+ 0x2d8, /* CFG_CLKTRIM_2 */
+};
+
+/* Select the closest EMC rate that is higher than the requested rate */
+long tegra_emc_round_rate(unsigned long rate)
+{
+ int i;
+ int best = -1;
+ unsigned long distance = ULONG_MAX;
+
+ if (!tegra_emc_table)
+ return -EINVAL;
+
+ if (!emc_enable)
+ return -EINVAL;
+
+ pr_debug("%s: %lu\n", __func__, rate);
+
+ /* The EMC clock rate is twice the bus rate, and the bus rate is
+ * measured in kHz */
+ rate = rate / 2 / 1000;
+
+ for (i = 0; i < tegra_emc_table_size; i++) {
+ if (tegra_emc_table[i].rate >= rate &&
+ (tegra_emc_table[i].rate - rate) < distance) {
+ distance = tegra_emc_table[i].rate - rate;
+ best = i;
+ }
+ }
+
+ if (best < 0)
+ return -EINVAL;
+
+ pr_debug("%s: using %lu\n", __func__, tegra_emc_table[best].rate);
+
+ return tegra_emc_table[best].rate * 2 * 1000;
+}
+
+/* The EMC registers have shadow registers. When the EMC clock is updated
+ * in the clock controller, the shadow registers are copied to the active
+ * registers, allowing glitchless memory bus frequency changes.
+ * This function updates the shadow registers for a new clock frequency,
+ * and relies on the clock lock on the emc clock to avoid races between
+ * multiple frequency changes */
+int tegra_emc_set_rate(unsigned long rate)
+{
+ int i;
+ int j;
+
+ if (!tegra_emc_table)
+ return -EINVAL;
+
+ /* The EMC clock rate is twice the bus rate, and the bus rate is
+ * measured in kHz */
+ rate = rate / 2 / 1000;
+
+ for (i = 0; i < tegra_emc_table_size; i++)
+ if (tegra_emc_table[i].rate == rate)
+ break;
+
+ if (i >= tegra_emc_table_size)
+ return -EINVAL;
+
+ pr_debug("%s: setting to %lu\n", __func__, rate);
+
+ for (j = 0; j < TEGRA_EMC_NUM_REGS; j++)
+ emc_writel(tegra_emc_table[i].regs[j], emc_reg_addr[j]);
+
+ emc_readl(tegra_emc_table[i].regs[TEGRA_EMC_NUM_REGS - 1]);
+
+ return 0;
+}
+
+void tegra_init_emc(const struct tegra_emc_table *table, int table_size)
+{
+ tegra_emc_table = table;
+ tegra_emc_table_size = table_size;
+}
diff --git a/arch/arm/mach-tegra/tegra2_emc.h b/arch/arm/mach-tegra/tegra2_emc.h
new file mode 100644
index 0000000..3515e57
--- /dev/null
+++ b/arch/arm/mach-tegra/tegra2_emc.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * Author:
+ * Colin Cross <ccross@google.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#define TEGRA_EMC_NUM_REGS 46
+
+struct tegra_emc_table {
+ unsigned long rate;
+ u32 regs[TEGRA_EMC_NUM_REGS];
+};
+
+int tegra_emc_set_rate(unsigned long rate);
+long tegra_emc_round_rate(unsigned long rate);
+void tegra_init_emc(const struct tegra_emc_table *table, int table_size);
--
1.7.3.1
next prev parent reply other threads:[~2011-02-19 22:26 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-19 22:25 [PATCH v2 12/21] ARM: tegra: clock: Add shared bus clock type Colin Cross
2011-02-19 22:25 ` [PATCH v2 00/21] Tegra clock updates for 2.6.39 Colin Cross
2011-02-19 22:25 ` [PATCH v2 01/21] ARM: tegra: clock: enable clk reset for non-peripheral clocks Colin Cross
2011-02-21 4:05 ` Olof Johansson
2011-02-19 22:25 ` [PATCH v2 02/21] ARM: tegra: clock: Don't BUG on changing an enabled PLL Colin Cross
2011-02-21 4:06 ` Olof Johansson
2011-02-21 6:46 ` Colin Cross
2011-02-19 22:25 ` [PATCH v2 03/21] ARM: tegra: clock: Drop debugging Colin Cross
2011-02-21 4:07 ` Olof Johansson
2011-02-21 6:56 ` Colin Cross
2011-02-19 22:25 ` [PATCH v2 04/21] ARM: tegra: clock: Don't use PLL lock bits Colin Cross
2011-02-21 4:07 ` Olof Johansson
2011-02-19 22:25 ` [PATCH v2 05/21] ARM: tegra: clock: Disable clocks left on by bootloader Colin Cross
2011-02-21 0:40 ` Olof Johansson
2011-02-21 3:43 ` Colin Cross
2011-02-21 4:03 ` Olof Johansson
2011-02-19 22:25 ` [PATCH v2 06/21] ARM: tegra: clock: Initialize clocks that have no enable Colin Cross
2011-02-21 4:08 ` Olof Johansson
2011-02-19 22:25 ` [PATCH v2 07/21] ARM: tegra: clock: Drop CPU dvfs Colin Cross
2011-02-21 4:09 ` Olof Johansson
2011-02-19 22:25 ` [PATCH v2 08/21] ARM: tegra: clock: Rearrange static clock tables Colin Cross
2011-02-21 4:09 ` Olof Johansson
2011-02-19 22:25 ` [PATCH v2 09/21] ARM: tegra: clock: Move unshared clk struct members into union Colin Cross
2011-02-21 4:10 ` Olof Johansson
2011-02-21 7:00 ` Colin Cross
2011-02-19 22:25 ` [PATCH v2 10/21] ARM: tegra: clock: Convert global lock to a lock per clock Colin Cross
2011-02-21 4:11 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 11/21] ARM: tegra: cpufreq: Take an extra reference to pllx Colin Cross
2011-02-21 4:12 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 12/21] ARM: tegra: clock: Add shared bus clock type Colin Cross
2011-02-19 22:26 ` [PATCH v2 13/21] ARM: tegra: clock: Remove unnecessary uses of #ifdef CONFIG_DEBUG_FS Colin Cross
2011-02-21 4:17 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 14/21] ARM: tegra: clock: Refcount periph clock enables Colin Cross
2011-02-21 4:18 ` Olof Johansson
2011-02-21 7:06 ` Colin Cross
2011-02-19 22:26 ` [PATCH v2 15/21] ARM: tegra: clock: Round rate before setting rate Colin Cross
2011-02-21 4:19 ` Olof Johansson
2011-02-21 7:52 ` Colin Cross
2011-02-19 22:26 ` Colin Cross [this message]
2011-02-21 4:20 ` [PATCH v2 16/21] ARM: tegra: Add external memory controller driver Olof Johansson
2011-02-19 22:26 ` [PATCH v2 17/21] ARM: tegra: clocks: Add emc scaling Colin Cross
2011-02-21 4:21 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 18/21] ARM: tegra: cpufreq: Adjust memory frequency with cpu frequency Colin Cross
2011-02-21 4:23 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 19/21] ARM: tegra: clock: Add function to set SDMMC tap delay Colin Cross
2011-02-21 4:26 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 20/21] ARM: tegra: clock: Fix clock issues in suspend Colin Cross
2011-02-21 4:28 ` Olof Johansson
2011-02-19 22:26 ` [PATCH v2 21/21] ARM: tegra: clock: Miscellaneous clock updates Colin Cross
2011-02-21 4:28 ` Olof Johansson
2011-02-21 4:15 ` [PATCH v2 12/21] ARM: tegra: clock: Add shared bus clock type Olof Johansson
2011-02-21 7:02 ` Colin Cross
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1298154371-5641-18-git-send-email-ccross@android.com \
--to=ccross@android.com \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).