Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759677Ab2KBQVy (ORCPT ); Fri, 2 Nov 2012 12:21:54 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:45932 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759143Ab2KBQVv (ORCPT ); Fri, 2 Nov 2012 12:21:51 -0400 From: Murali Karicheri To: , , , , , , , , , , , , , , , , , , CC: Murali Karicheri Subject: [RFC PATCH 1/2] memory: davinci - add aemif controller platform driver Date: Fri, 2 Nov 2012 12:21:17 -0400 Message-ID: <1351873278-27325-2-git-send-email-m-karicheri2@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1351873278-27325-1-git-send-email-m-karicheri2@ti.com> References: <1351873278-27325-1-git-send-email-m-karicheri2@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 16626 Lines: 583 This is a platform driver for asynchronous external memory interface available on TI SoCs. This driver was previously located inside the mach-davinci folder. As this DaVinci IP is re-used across multiple family of devices such as c6x, keystone etc, the driver is moved to drivers. The driver configures async bus parameters associated with a particular chip select. For DaVinci controller driver and driver for other async devices such as NOR flash, ASRAM etc, the bus confuguration is done by this driver at init time. A set of APIs (set/get) provided to update the values based on specific driver usage. Signed-off-by: Murali Karicheri --- .../devicetree/bindings/arm/davinci/aemif.txt | 62 +++ drivers/memory/Kconfig | 10 + drivers/memory/Makefile | 1 + drivers/memory/davinci-aemif.c | 397 ++++++++++++++++++++ include/linux/platform_data/davinci-aemif.h | 47 +++ 5 files changed, 517 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/davinci/aemif.txt create mode 100644 drivers/memory/davinci-aemif.c create mode 100644 include/linux/platform_data/davinci-aemif.h diff --git a/Documentation/devicetree/bindings/arm/davinci/aemif.txt b/Documentation/devicetree/bindings/arm/davinci/aemif.txt new file mode 100644 index 0000000..7d70d42 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/davinci/aemif.txt @@ -0,0 +1,62 @@ +* Texas Instruments Davinci AEMIF bus interface + +This file provides information for the davinci-emif chip select +bindings. + +This is a sub device node inside the davinci-emif device node +to describe a async bus for a specific chip select. For NAND, +CFI flash device bindings described inside an aemif node, +etc, a cs sub node is defined to associate the bus parameter +bindings used by the device. + +Required properties:= +- compatible: "ti,davinci-cs"; +- #address-cells = <1>; +- #size-cells = <1>; +- cs - cs used by the device (NAND, CFI flash etc. values in the range: 2-5 + +Optional properties:- +- asize - asynchronous data bus width (0 - 8bit, 1 - 16 bit) + All of the params below in nanoseconds + +- ta - Minimum turn around time +- rhold - read hold width +- rstobe - read strobe width +- rsetup - read setup width +- whold - write hold width +- wstrobe - write strobe width +- wsetup - write setup width +- ss - enable/disable select strobe (0 - disable, 1 - enable) +- ew - enable/disable extended wait cycles (0 - disable, 1 - enable) + +Example for davinci nand chip select + +aemif@60000000 { + + compatible = "ti,davinci-aemif"; + #address-cells = <2>; + #size-cells = <1>; + + nand_cs:cs2@70000000 { + compatible = "ti,davinci-cs"; + #address-cells = <1>; + #size-cells = <1>; + cs = <2>; + asize = <1>; + ta = <24>; + rhold = <48>; + rstrobe = <390>; + rsetup = <96>; + whold = <48>; + wstrobe = <390>; + wsetup = <96>; + }; + + nand@2,0 { + + .... + + }; +}; + + diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig index 067f311..2636a95 100644 --- a/drivers/memory/Kconfig +++ b/drivers/memory/Kconfig @@ -40,4 +40,14 @@ config TEGRA30_MC analysis, especially for IOMMU/SMMU(System Memory Management Unit) module. +config TI_DAVINCI_AEMIF + bool "Texas Instruments DaVinci AEMIF driver" + help + This driver is for the AEMIF module available in Texas Instruments + SoCs. AEMIF stands for Asynchronous External Memory Interface and + is intended to provide a glue-less interface to a variety of + asynchronuous memory devices like ASRAM, NOR and NAND memory. A total + of 256M bytes of any of these memories can be accessed at a given + time via four chip selects with 64M byte access per chip select. + endif diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile index 42b3ce9..246aa61 100644 --- a/drivers/memory/Makefile +++ b/drivers/memory/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_TI_EMIF) += emif.o obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o obj-$(CONFIG_TEGRA30_MC) += tegra30-mc.o +obj-$(CONFIG_TI_DAVINCI_AEMIF) += davinci-aemif.o diff --git a/drivers/memory/davinci-aemif.c b/drivers/memory/davinci-aemif.c new file mode 100644 index 0000000..6c42116 --- /dev/null +++ b/drivers/memory/davinci-aemif.c @@ -0,0 +1,397 @@ +/* + * AEMIF support for DaVinci SoCs + * + * Copyright (C) 2010 Texas Instruments Incorporated. http://www.ti.com/ + * Copyright (C) Heiko Schocher + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Timing value configuration */ +#define TA(x) ((x) << 2) +#define RHOLD(x) ((x) << 4) +#define RSTROBE(x) ((x) << 7) +#define RSETUP(x) ((x) << 13) +#define WHOLD(x) ((x) << 17) +#define WSTROBE(x) ((x) << 20) +#define WSETUP(x) ((x) << 26) +#define EW(x) ((x) << 30) +#define SS(x) ((x) << 31) + +#define ASIZE_MAX 0x1 +#define TA_MAX 0x3 +#define RHOLD_MAX 0x7 +#define RSTROBE_MAX 0x3f +#define RSETUP_MAX 0xf +#define WHOLD_MAX 0x7 +#define WSTROBE_MAX 0x3f +#define WSETUP_MAX 0xf +#define EW_MAX 0x1 +#define SS_MAX 0x1 +#define NUM_CS 4 + +#define CONFIG_MASK (TA(TA_MAX) | \ + RHOLD(RHOLD_MAX) | \ + RSTROBE(RSTROBE_MAX) | \ + RSETUP(RSETUP_MAX) | \ + WHOLD(WHOLD_MAX) | \ + WSTROBE(WSTROBE_MAX) | \ + WSETUP(WSETUP_MAX) | \ + EW(EW_MAX) | SS(SS_MAX) | \ + ASIZE_MAX) + +#define DRV_NAME "davinci-aemif" + +struct aemif_device { + struct davinci_aemif_pdata *cfg; + void __iomem *base; + struct clk *clk; +}; + +static struct aemif_device *aemif; +/** + * aemif_calc_rate - calculate timing data. + * @wanted: The cycle time needed in nanoseconds. + * @clk: The input clock rate in kHz. + * @max: The maximum divider value that can be programmed. + * + * On success, returns the calculated timing value minus 1 for easy + * programming into AEMIF timing registers, else negative errno. + */ +static int aemif_calc_rate(int wanted, unsigned long clk, int max) +{ + int result; + + result = DIV_ROUND_UP((wanted * clk), NSEC_PER_MSEC) - 1; + + pr_debug("%s: result %d from %ld, %d\n", __func__, result, clk, wanted); + + /* It is generally OK to have a more relaxed timing than requested... */ + if (result < 0) + result = 0; + + /* ... But configuring tighter timings is not an option. */ + else if (result > max) + result = -EINVAL; + + return result; +} + +/** + * davinci_aemif_config_abus - configure async bus parameters given + * AEMIF interface + * @cs: chip-select to program the timing values for + * @data: aemif chip select configuration + * @base: aemif io mapped configuration base + * + * This function programs the given timing values (in real clock) into the + * AEMIF registers taking the AEMIF clock into account. + * + * This function does not use any locking while programming the AEMIF + * because it is expected that there is only one user of a given + * chip-select. + * + * Returns 0 on success, else negative errno. + */ +static int davinci_aemif_config_abus(unsigned int cs, + void __iomem *base, + struct davinci_aemif_cs_data *data) +{ + int ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup; + unsigned offset = A1CR_OFFSET + cs * 4; + unsigned long clkrate; + unsigned set, val; + + if (!data) + return -EINVAL; + + clkrate = clk_get_rate(aemif->clk); + + clkrate /= 1000; /* turn clock into kHz for ease of use */ + + ta = aemif_calc_rate(data->ta, clkrate, TA_MAX); + rhold = aemif_calc_rate(data->rhold, clkrate, RHOLD_MAX); + rstrobe = aemif_calc_rate(data->rstrobe, clkrate, RSTROBE_MAX); + rsetup = aemif_calc_rate(data->rsetup, clkrate, RSETUP_MAX); + whold = aemif_calc_rate(data->whold, clkrate, WHOLD_MAX); + wstrobe = aemif_calc_rate(data->wstrobe, clkrate, WSTROBE_MAX); + wsetup = aemif_calc_rate(data->wsetup, clkrate, WSETUP_MAX); + + if (ta < 0 || rhold < 0 || rstrobe < 0 || rsetup < 0 || + whold < 0 || wstrobe < 0 || wsetup < 0) { + pr_err("%s: cannot get suitable timings\n", __func__); + return -EINVAL; + } + + set = TA(ta) | RHOLD(rhold) | RSTROBE(rstrobe) | RSETUP(rsetup) | + WHOLD(whold) | WSTROBE(wstrobe) | WSETUP(wsetup); + + set |= (data->asize & ACR_ASIZE_MASK); + if (data->enable_ew) + set |= ACR_EW_MASK; + if (data->enable_ss) + set |= ACR_SS_MASK; + + val = readl(aemif->base + offset); + val &= ~CONFIG_MASK; + val |= set; + writel(val, aemif->base + offset); + + return 0; +} + +/** + * get_cs_data - helper function to get bus configuration data for a given cs + * @cs: chip-select, values 2-5 + */ +static struct davinci_aemif_cs_data *get_cs_data(int cs) +{ + int i; + + for (i = 0; i < aemif->cfg->num_cs; i++) { + if (cs == aemif->cfg->cs_data[i].cs) + break; + } + + if (i == aemif->cfg->num_cs) + return NULL; + + return &aemif->cfg->cs_data[i]; +} + +/** + * davinci_aemif_set_abus_params - Set bus configuration data for a given cs + * @cs: chip-select, values 2-5 + * @data: ptr to a struct to hold the configuration data to be set + * + * This function is called to configure emif bus parameters for a given cs. + * Users call this function after calling davinci_aemif_get_abus_params() + * to get current parameters, modify and call this function + */ +int davinci_aemif_set_abus_params(unsigned int cs, + struct davinci_aemif_cs_data *data) +{ + struct davinci_aemif_cs_data *curr_cs_data; + int ret = -EINVAL, chip_cs; + + if (data == NULL) + return ret; + + if (aemif->base == NULL) + return ret; + + /* translate to chip CS which starts at 2 */ + chip_cs = cs + 2; + + curr_cs_data = get_cs_data(chip_cs); + if (curr_cs_data) { + ret = davinci_aemif_config_abus(chip_cs, aemif->base, data); + if (!ret) { + *curr_cs_data = *data; + return 0; + } + } + + return ret; +} +EXPORT_SYMBOL(davinci_aemif_set_abus_params); + +/** + * davinci_aemif_get_abus_params - Get bus configuration data for a given cs + * @cs: chip-select, values 2-5 + * returns: ptr to a struct having the current configuration data + */ +struct davinci_aemif_cs_data *davinci_aemif_get_abus_params(unsigned int cs) +{ + /* translate to chip CS which starts at 2 */ + return get_cs_data(cs + 2); +} +EXPORT_SYMBOL(davinci_aemif_get_abus_params); + +#if defined(CONFIG_OF) +/** + * dv_get_value - helper function to read a attribute valye + * @np: device node ptr + * @name: name of the attribute + * returns: value of the attribute + */ +static int dv_get_value(struct device_node *np, const char *name) +{ + u32 data; + int ret; + + ret = of_property_read_u32(np, name, &data); + if (ret != 0) + return ret; + + return data; +} + +/** + * of_davinci_aemif_parse_abus_config - parse bus config data from a cs node + * @np: device node ptr + * + * This function update the emif async bus configuration based on the values + * configured in a cs device binding node. + */ +static int of_davinci_aemif_parse_abus_config(struct device_node *np) +{ + struct davinci_aemif_cs_data *data; + int cs; + + + cs = dv_get_value(np, "cs"); + if (cs < 2 || cs >= NUM_CS) + return -EINVAL; + + if (aemif->cfg->num_cs >= NUM_CS) + return -EINVAL; + + data = &aemif->cfg->cs_data[aemif->cfg->num_cs++]; + data->cs = cs; + data->ta = dv_get_value(np, "ta"); + data->rhold = dv_get_value(np, "rhold"); + data->rstrobe = dv_get_value(np, "rstrobe"); + data->rsetup = dv_get_value(np, "rsetup"); + data->whold = dv_get_value(np, "whold"); + data->wstrobe = dv_get_value(np, "wstrobe"); + data->wsetup = dv_get_value(np, "wsetup"); + data->asize = dv_get_value(np, "asize"); + data->enable_ew = dv_get_value(np, "ew"); + data->enable_ss = dv_get_value(np, "ss"); + return 0; +} +#endif + +static const struct of_device_id davinci_aemif_of_match[] __devinitconst = { + { .compatible = "ti,davinci-aemif", }, + {}, +}; + +static const struct of_device_id davinci_cs_of_match[] __devinitconst = { + { .compatible = "ti,davinci-cs", }, + {}, +}; + +/** + * of_davinci_aemif_cs_init - init cs data based on cs device nodes + * @np: device node ptr + * + * For every controller device node, there is a cs device node that + * describe the bus configuration parameters. This functions iterate + * over these nodes and update the cs data array. + */ +static int of_davinci_aemif_cs_init(struct device_node *aemif_np) +{ + struct device_node *np = aemif_np; + + if (!np) + return -ENODEV; + + for_each_matching_node(np, davinci_cs_of_match) + of_davinci_aemif_parse_abus_config(np); + return 0; +} + +static int __devinit davinci_aemif_probe(struct platform_device *pdev) +{ + struct davinci_aemif_pdata *cfg; + int ret = -ENODEV, i; + struct resource *res; + + aemif = devm_kzalloc(&pdev->dev, sizeof(*aemif), GFP_KERNEL); + + if (!aemif) + return -ENOMEM; + + aemif->clk = clk_get(NULL, "aemif"); + if (IS_ERR(aemif->clk)) + return PTR_ERR(aemif->clk); + + clk_prepare_enable(aemif->clk); + + if (pdev->dev.platform_data == NULL) { + /* Not platform data, we get the cs data from the cs nodes */ + cfg = devm_kzalloc(&pdev->dev, sizeof(*cfg), GFP_KERNEL); + if (cfg == NULL) + return -ENOMEM; + + aemif->cfg = cfg; + if (of_davinci_aemif_cs_init(pdev->dev.of_node) < 0) { + pr_err("No platform data or cs of node present\n"); + goto error; + } + } else { + cfg = pdev->dev.platform_data; + aemif->cfg = cfg; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + pr_err("No IO memory address defined\n"); + goto error; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + aemif->base = devm_request_and_ioremap(&pdev->dev, res); + if (!aemif->base) { + ret = -EBUSY; + pr_err("ioremap failed\n"); + goto error; + } + + for (i = 0; i < cfg->num_cs; i++) { + ret = davinci_aemif_config_abus(cfg->cs_data[i].cs, + aemif->base, &cfg->cs_data[i]); + if (ret < 0) { + pr_err("Error configuring chip select %d\n", + cfg->cs_data[i].cs); + goto error; + } + } + return ret; +error: + clk_disable_unprepare(aemif->clk); + clk_put(aemif->clk); + return ret; +} + +static struct platform_driver davinci_aemif_driver = { + .probe = davinci_aemif_probe, + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + .of_match_table = davinci_aemif_of_match, + }, +}; + +static int __init davinci_aemif_init(void) +{ + return platform_driver_register(&davinci_aemif_driver); +} +subsys_initcall(davinci_aemif_init); + +static void __exit davinci_aemif_exit(void) +{ + clk_disable_unprepare(aemif->clk); + clk_put(aemif->clk); + platform_driver_unregister(&davinci_aemif_driver); +} +module_exit(davinci_aemif_exit); + +MODULE_AUTHOR("Murali Karicheri "); +MODULE_DESCRIPTION("Texas Instruments AEMIF driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:" DRV_NAME); diff --git a/include/linux/platform_data/davinci-aemif.h b/include/linux/platform_data/davinci-aemif.h new file mode 100644 index 0000000..03f3ad0 --- /dev/null +++ b/include/linux/platform_data/davinci-aemif.h @@ -0,0 +1,47 @@ +/* + * TI DaVinci AEMIF support + * + * Copyright 2010 (C) Texas Instruments, Inc. http://www.ti.com/ + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ +#ifndef _MACH_DAVINCI_AEMIF_H +#define _MACH_DAVINCI_AEMIF_H + +#define NRCSR_OFFSET 0x00 +#define AWCCR_OFFSET 0x04 +#define A1CR_OFFSET 0x10 + +#define ACR_ASIZE_MASK 0x3 +#define ACR_EW_MASK BIT(30) +#define ACR_SS_MASK BIT(31) +#define ASIZE_16BIT 1 + +struct davinci_aemif_cs_data { + u8 cs; + u16 wstrobe; + u16 rstrobe; + u8 wsetup; + u8 whold; + u8 rsetup; + u8 rhold; + u8 ta; + u8 enable_ss; + u8 enable_ew; + u8 asize; +}; + +struct davinci_aemif_pdata { + u8 num_cs; + struct davinci_aemif_cs_data cs_data[4]; +}; + +/* API to Get current Asynchrnous emif bus parameters */ +struct davinci_aemif_cs_data *davinci_aemif_get_abus_params(unsigned int cs); + +/* API to Set current Asynchrnous emif bus parameters */ +int davinci_aemif_set_abus_params(unsigned int cs, + struct davinci_aemif_cs_data *data); +#endif -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/