diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/arm/mach-tegra/tegra2_emc.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/arm/mach-tegra/tegra2_emc.c | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/arch/arm/mach-tegra/tegra2_emc.c b/ANDROID_3.4.5/arch/arm/mach-tegra/tegra2_emc.c new file mode 100644 index 00000000..5070d833 --- /dev/null +++ b/ANDROID_3.4.5/arch/arm/mach-tegra/tegra2_emc.c @@ -0,0 +1,356 @@ +/* + * Copyright (C) 2011 Google, Inc. + * + * Author: + * Colin Cross <ccross@android.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/device.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/platform_data/tegra_emc.h> + +#include <mach/iomap.h> + +#include "tegra2_emc.h" +#include "fuse.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 struct platform_device *emc_pdev; +static void __iomem *emc_regbase; + +static inline void emc_writel(u32 val, unsigned long addr) +{ + writel(val, emc_regbase + addr); +} + +static inline u32 emc_readl(unsigned long addr) +{ + return readl(emc_regbase + 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) +{ + struct tegra_emc_pdata *pdata; + int i; + int best = -1; + unsigned long distance = ULONG_MAX; + + if (!emc_pdev) + return -EINVAL; + + pdata = emc_pdev->dev.platform_data; + + 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 < pdata->num_tables; i++) { + if (pdata->tables[i].rate >= rate && + (pdata->tables[i].rate - rate) < distance) { + distance = pdata->tables[i].rate - rate; + best = i; + } + } + + if (best < 0) + return -EINVAL; + + pr_debug("%s: using %lu\n", __func__, pdata->tables[best].rate); + + return pdata->tables[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) +{ + struct tegra_emc_pdata *pdata; + int i; + int j; + + if (!emc_pdev) + return -EINVAL; + + pdata = emc_pdev->dev.platform_data; + + /* + * 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 < pdata->num_tables; i++) + if (pdata->tables[i].rate == rate) + break; + + if (i >= pdata->num_tables) + return -EINVAL; + + pr_debug("%s: setting to %lu\n", __func__, rate); + + for (j = 0; j < TEGRA_EMC_NUM_REGS; j++) + emc_writel(pdata->tables[i].regs[j], emc_reg_addr[j]); + + emc_readl(pdata->tables[i].regs[TEGRA_EMC_NUM_REGS - 1]); + + return 0; +} + +#ifdef CONFIG_OF +static struct device_node *tegra_emc_ramcode_devnode(struct device_node *np) +{ + struct device_node *iter; + u32 reg; + + for_each_child_of_node(np, iter) { + if (of_property_read_u32(np, "nvidia,ram-code", ®)) + continue; + if (reg == tegra_bct_strapping) + return of_node_get(iter); + } + + return NULL; +} + +static struct tegra_emc_pdata *tegra_emc_dt_parse_pdata( + struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct device_node *tnp, *iter; + struct tegra_emc_pdata *pdata; + int ret, i, num_tables; + + if (!np) + return NULL; + + if (of_find_property(np, "nvidia,use-ram-code", NULL)) { + tnp = tegra_emc_ramcode_devnode(np); + if (!tnp) + dev_warn(&pdev->dev, + "can't find emc table for ram-code 0x%02x\n", + tegra_bct_strapping); + } else + tnp = of_node_get(np); + + if (!tnp) + return NULL; + + num_tables = 0; + for_each_child_of_node(tnp, iter) + if (of_device_is_compatible(iter, "nvidia,tegra20-emc-table")) + num_tables++; + + if (!num_tables) { + pdata = NULL; + goto out; + } + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + pdata->tables = devm_kzalloc(&pdev->dev, + sizeof(*pdata->tables) * num_tables, + GFP_KERNEL); + + i = 0; + for_each_child_of_node(tnp, iter) { + u32 prop; + + ret = of_property_read_u32(iter, "clock-frequency", &prop); + if (ret) { + dev_err(&pdev->dev, "no clock-frequency in %s\n", + iter->full_name); + continue; + } + pdata->tables[i].rate = prop; + + ret = of_property_read_u32_array(iter, "nvidia,emc-registers", + pdata->tables[i].regs, + TEGRA_EMC_NUM_REGS); + if (ret) { + dev_err(&pdev->dev, + "malformed emc-registers property in %s\n", + iter->full_name); + continue; + } + + i++; + } + pdata->num_tables = i; + +out: + of_node_put(tnp); + return pdata; +} +#else +static struct tegra_emc_pdata *tegra_emc_dt_parse_pdata( + struct platform_device *pdev) +{ + return NULL; +} +#endif + +static struct tegra_emc_pdata __devinit *tegra_emc_fill_pdata(struct platform_device *pdev) +{ + struct clk *c = clk_get_sys(NULL, "emc"); + struct tegra_emc_pdata *pdata; + unsigned long khz; + int i; + + WARN_ON(pdev->dev.platform_data); + BUG_ON(IS_ERR_OR_NULL(c)); + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + pdata->tables = devm_kzalloc(&pdev->dev, sizeof(*pdata->tables), + GFP_KERNEL); + + pdata->tables[0].rate = clk_get_rate(c) / 2 / 1000; + + for (i = 0; i < TEGRA_EMC_NUM_REGS; i++) + pdata->tables[0].regs[i] = emc_readl(emc_reg_addr[i]); + + pdata->num_tables = 1; + + khz = pdata->tables[0].rate; + dev_info(&pdev->dev, "no tables provided, using %ld kHz emc, " + "%ld kHz mem\n", khz * 2, khz); + + return pdata; +} + +static int __devinit tegra_emc_probe(struct platform_device *pdev) +{ + struct tegra_emc_pdata *pdata; + struct resource *res; + + if (!emc_enable) { + dev_err(&pdev->dev, "disabled per module parameter\n"); + return -ENODEV; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "missing register base\n"); + return -ENOMEM; + } + + emc_regbase = devm_request_and_ioremap(&pdev->dev, res); + if (!emc_regbase) { + dev_err(&pdev->dev, "failed to remap registers\n"); + return -ENOMEM; + } + + pdata = pdev->dev.platform_data; + + if (!pdata) + pdata = tegra_emc_dt_parse_pdata(pdev); + + if (!pdata) + pdata = tegra_emc_fill_pdata(pdev); + + pdev->dev.platform_data = pdata; + + emc_pdev = pdev; + + return 0; +} + +static struct of_device_id tegra_emc_of_match[] __devinitdata = { + { .compatible = "nvidia,tegra20-emc", }, + { }, +}; + +static struct platform_driver tegra_emc_driver = { + .driver = { + .name = "tegra-emc", + .owner = THIS_MODULE, + .of_match_table = tegra_emc_of_match, + }, + .probe = tegra_emc_probe, +}; + +static int __init tegra_emc_init(void) +{ + return platform_driver_register(&tegra_emc_driver); +} +device_initcall(tegra_emc_init); |