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ARM: tegra: emc: convert tegra2_emc to a platform driver
This is the first step in making it device-tree aware and get rid of the in-kernel EMC tables (of which there are none in mainline, thankfully). Changes since v3: * moved to devm_request_and_ioremap() in probe() Changes since v2: * D'oh -- missed a couple of variables that were added, never used and then later removed in a later patch. Changes since v1: * Fixed messed up indentation * Removed code that should be gone (was added here and removed later in series) Signed-off-by: Olof Johansson <olof@lixom.net> Acked-by: Stephen Warren <swarren@nvidia.com>
This commit is contained in:
Olof Johansson
parent
dee4718330
commit
17711dbf47
@ -16,10 +16,13 @@
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*/
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/platform_data/tegra_emc.h>
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#include <mach/iomap.h>
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@ -32,18 +35,17 @@ static bool emc_enable;
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#endif
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module_param(emc_enable, bool, 0644);
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static void __iomem *emc = IO_ADDRESS(TEGRA_EMC_BASE);
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static const struct tegra_emc_table *tegra_emc_table;
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static int tegra_emc_table_size;
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static struct platform_device *emc_pdev;
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static void __iomem *emc_regbase;
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static inline void emc_writel(u32 val, unsigned long addr)
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{
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writel(val, emc + addr);
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writel(val, emc_regbase + addr);
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}
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static inline u32 emc_readl(unsigned long addr)
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{
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return readl(emc + addr);
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return readl(emc_regbase + addr);
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}
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static const unsigned long emc_reg_addr[TEGRA_EMC_NUM_REGS] = {
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@ -98,15 +100,15 @@ static const unsigned long emc_reg_addr[TEGRA_EMC_NUM_REGS] = {
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/* Select the closest EMC rate that is higher than the requested rate */
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long tegra_emc_round_rate(unsigned long rate)
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{
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struct tegra_emc_pdata *pdata;
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int i;
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int best = -1;
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unsigned long distance = ULONG_MAX;
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if (!tegra_emc_table)
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if (!emc_pdev)
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return -EINVAL;
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if (!emc_enable)
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return -EINVAL;
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pdata = emc_pdev->dev.platform_data;
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pr_debug("%s: %lu\n", __func__, rate);
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@ -116,10 +118,10 @@ long tegra_emc_round_rate(unsigned long rate)
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*/
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rate = rate / 2 / 1000;
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for (i = 0; i < tegra_emc_table_size; i++) {
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if (tegra_emc_table[i].rate >= rate &&
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(tegra_emc_table[i].rate - rate) < distance) {
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distance = tegra_emc_table[i].rate - rate;
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for (i = 0; i < pdata->num_tables; i++) {
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if (pdata->tables[i].rate >= rate &&
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(pdata->tables[i].rate - rate) < distance) {
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distance = pdata->tables[i].rate - rate;
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best = i;
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}
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}
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@ -127,9 +129,9 @@ long tegra_emc_round_rate(unsigned long rate)
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if (best < 0)
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return -EINVAL;
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pr_debug("%s: using %lu\n", __func__, tegra_emc_table[best].rate);
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pr_debug("%s: using %lu\n", __func__, pdata->tables[best].rate);
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return tegra_emc_table[best].rate * 2 * 1000;
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return pdata->tables[best].rate * 2 * 1000;
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}
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/*
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@ -142,37 +144,81 @@ long tegra_emc_round_rate(unsigned long rate)
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*/
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int tegra_emc_set_rate(unsigned long rate)
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{
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struct tegra_emc_pdata *pdata;
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int i;
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int j;
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if (!tegra_emc_table)
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if (!emc_pdev)
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return -EINVAL;
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pdata = emc_pdev->dev.platform_data;
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/*
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* The EMC clock rate is twice the bus rate, and the bus rate is
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* measured in kHz
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*/
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rate = rate / 2 / 1000;
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for (i = 0; i < tegra_emc_table_size; i++)
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if (tegra_emc_table[i].rate == rate)
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for (i = 0; i < pdata->num_tables; i++)
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if (pdata->tables[i].rate == rate)
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break;
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if (i >= tegra_emc_table_size)
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if (i >= pdata->num_tables)
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return -EINVAL;
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pr_debug("%s: setting to %lu\n", __func__, rate);
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for (j = 0; j < TEGRA_EMC_NUM_REGS; j++)
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emc_writel(tegra_emc_table[i].regs[j], emc_reg_addr[j]);
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emc_writel(pdata->tables[i].regs[j], emc_reg_addr[j]);
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emc_readl(tegra_emc_table[i].regs[TEGRA_EMC_NUM_REGS - 1]);
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emc_readl(pdata->tables[i].regs[TEGRA_EMC_NUM_REGS - 1]);
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return 0;
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}
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void tegra_init_emc(const struct tegra_emc_table *table, int table_size)
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static int __devinit tegra_emc_probe(struct platform_device *pdev)
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{
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tegra_emc_table = table;
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tegra_emc_table_size = table_size;
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struct tegra_emc_pdata *pdata;
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struct resource *res;
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if (!emc_enable) {
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dev_err(&pdev->dev, "disabled per module parameter\n");
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return -ENODEV;
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}
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pdata = pdev->dev.platform_data;
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if (!pdata) {
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dev_err(&pdev->dev, "missing platform data\n");
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return -ENXIO;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(&pdev->dev, "missing register base\n");
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return -ENOMEM;
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}
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emc_regbase = devm_request_and_ioremap(&pdev->dev, res);
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if (!emc_regbase) {
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dev_err(&pdev->dev, "failed to remap registers\n");
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return -ENOMEM;
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}
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emc_pdev = pdev;
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return 0;
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}
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static struct platform_driver tegra_emc_driver = {
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.driver = {
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.name = "tegra-emc",
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.owner = THIS_MODULE,
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},
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.probe = tegra_emc_probe,
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};
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static int __init tegra_emc_init(void)
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{
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return platform_driver_register(&tegra_emc_driver);
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}
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device_initcall(tegra_emc_init);
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@ -15,13 +15,10 @@
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*
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*/
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#define TEGRA_EMC_NUM_REGS 46
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struct tegra_emc_table {
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unsigned long rate;
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u32 regs[TEGRA_EMC_NUM_REGS];
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};
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#ifndef __MACH_TEGRA_TEGRA2_EMC_H_
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#define __MACH_TEGRA_TEGRA2_EMC_H
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int tegra_emc_set_rate(unsigned long rate);
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long tegra_emc_round_rate(unsigned long rate);
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void tegra_init_emc(const struct tegra_emc_table *table, int table_size);
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#endif
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34
include/linux/platform_data/tegra_emc.h
Normal file
34
include/linux/platform_data/tegra_emc.h
Normal file
@ -0,0 +1,34 @@
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/*
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* Copyright (C) 2011 Google, Inc.
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*
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* Author:
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* Colin Cross <ccross@android.com>
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* Olof Johansson <olof@lixom.net>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#ifndef __TEGRA_EMC_H_
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#define __TEGRA_EMC_H_
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#define TEGRA_EMC_NUM_REGS 46
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struct tegra_emc_table {
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unsigned long rate;
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u32 regs[TEGRA_EMC_NUM_REGS];
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};
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struct tegra_emc_pdata {
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int num_tables;
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struct tegra_emc_table *tables;
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};
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#endif
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