On Tuesday 06 November 2012 03:47 PM, Murali Karicheri wrote:
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 NAND controller driver and driver for other async
devices such as NOR flash, ASRAM etc, the bus confuguration is
done by this driver at probe. A set of APIs (set/get) are provided to
update the values based on specific driver usage.
This supports configuration of the bus either through platform_data or
through DT bindings.
Signed-off-by: Murali Karicheri <m-karicheri2@xxxxxx>
---
.../devicetree/bindings/memory/davinci-aemif.txt | 103 +++++
drivers/memory/Kconfig | 10 +
drivers/memory/Makefile | 1 +
drivers/memory/davinci-aemif.c | 479 ++++++++++++++++++++
include/linux/platform_data/davinci-aemif.h | 47 ++
5 files changed, 640 insertions(+)
create mode 100644 Documentation/devicetree/bindings/memory/davinci-aemif.txt
create mode 100644 drivers/memory/davinci-aemif.c
create mode 100644 include/linux/platform_data/davinci-aemif.h
Please split the DT and drivers/memory/* changes in two seperate
patches.
diff --git a/Documentation/devicetree/bindings/memory/davinci-aemif.txt b/Documentation/devicetree/bindings/memory/davinci-aemif.txt
new file mode 100644
index 0000000..a79b3ed
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory/davinci-aemif.txt
@@ -0,0 +1,103 @@
+* Texas Instruments Davinci AEMIF bus interface
+
+This file provides information for the davinci-emif device and
+async bus bindings.
+
+Required properties:=
+- compatible: "ti,davinci-aemif";
+- #address-cells : Should be either two or three. The first cell is the
+ chipselect number, and the remaining cells are the
+ offset into the chipselect.
+- #size-cells : Either one or two, depending on how large each chipselect
+ can be.
+- reg : contains offset/length value for AEMIF control registers space
+- ranges : Each range corresponds to a single chipselect, and cover
+ the entire access window as configured.
+
+Child device nodes describe the devices connected to IFC such as NOR (e.g.
+cfi-flash) and NAND (ti,davinci-nand, see Documentation/devicetree/bindings/
+mtd/davinci-nand.txt). There might be board specific devices like FPGAs.
+
+In addition, optional child sub nodes contains bindings for the async bus
+interface for a given chip select.
+
+Optional cs node properties:-
+- compatible: "ti,davinci-cs"
+
+ All of the params below in nanoseconds and are optional
+
+- ti,davinci-cs-asize - asynchronous data bus width (0 - 8bit, 1 - 16 bit)
+- ti,davinci-cs-ta - Minimum turn around time
+- ti,davinci-cs-rhold - read hold width
+- ti,davinci-cs-rstobe - read strobe width
+- ti,davinci-cs-rsetup - read setup width
+- ti,davinci-cs-whold - write hold width
+- ti,davinci-cs-wstrobe - write strobe width
+- ti,davinci-cs-wsetup - write setup width
+- ti,davinci-cs-ss - enable/disable select strobe (0 - disable, 1 - enable)
+- ti,davinci-cs-ew - enable/disable extended wait cycles (0 - disable, 1 - enable)
+
+if any of the above parameters are absent, hardware register default or that
+set by a boot loader are used.
+
+Example for aemif, davinci nand and nor flash chip select shown below.
+
+aemif@60000000 {
+ compatible = "ti,davinci-aemif";
+ #address-cells = <2>;
+ #size-cells = <1>;
+ reg = <0x68000000 0x80000>;
+ ranges = <2 0 0x60000000 0x02000000
+ 3 0 0x62000000 0x02000000
+ 4 0 0x64000000 0x02000000
+ 5 0 0x66000000 0x02000000
+ 6 0 0x68000000 0x02000000>;
+
+ nand_cs:cs2@60000000 {
+ compatible = "ti,davinci-cs";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ /* all timings in nanoseconds */
+ ti,davinci-cs-ta = <0>;
+ ti,davinci-cs-rhold = <7>;
+ ti,davinci-cs-rstrobe = <42>;
+ ti,davinci-cs-rsetup = <14>;
+ ti,davinci-cs-whold = <7>;
+ ti,davinci-cs-wstrobe = <42>;
+ ti,davinci-cs-wsetup = <14>;
+ };
+
+ nor_cs:cs3@62000000 {
+ compatible = "ti,davinci-cs";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ /* all timings in nanoseconds */
+ ti,davinci-cs-ta = <0>;
+ ti,davinci-cs-rhold = <7>;
+ ti,davinci-cs-rstrobe = <42>;
+ ti,davinci-cs-rsetup = <14>;
+ ti,davinci-cs-whold = <7>;
+ ti,davinci-cs-wstrobe = <42>;
+ ti,davinci-cs-wsetup = <14>;
+ ti,davinci-cs-asize = <1>;
+ };
+
+ nand@3,0 {
+ compatible = "ti,davinci-nand";
+ reg = <3 0x0 0x807ff
+ 6 0x0 0x8000>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ .. See Documentation/devicetree/bindings/mtd/davinci-nand.txt
+ };
+
+ flash@2,0 {
+ compatible = "cfi-flash";
+ reg = <2 0x0 0x400000>;
+ #address-cells = <1>;
+ #size-cells = <1>;
+ bank-width = <2>;
+ device-width = <2>;
+ };
+};
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"
Add some default depends on ARCH here otherwise, this driver
will get build for all the generic builds and might show
build errors.
+ 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..27a6995
--- /dev/null
+++ b/drivers/memory/davinci-aemif.c
@@ -0,0 +1,479 @@
+/*
+ * AEMIF support for DaVinci SoCs
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated. http://www.ti.com/
s/2010/2012
+ * Copyright (C) Heiko Schocher <hs@xxxxxxx>
+ *
+ * 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 <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_data/davinci-aemif.h>
+#include <linux/platform_device.h>
+#include <linux/time.h>
+
+#define TA_SHIFT 2
+#define RHOLD_SHIFT 4
+#define RSTROBE_SHIFT 7
+#define RSETUP_SHIFT 13
+#define WHOLD_SHIFT 17
+#define WSTROBE_SHIFT 20
+#define WSETUP_SHIFT 26
+#define EW_SHIFT 30
+#define SS_SHIFT 31
+
+#define TA(x) ((x) << TA_SHIFT)
+#define RHOLD(x) ((x) << RHOLD_SHIFT)
+#define RSTROBE(x) ((x) << RSTROBE_SHIFT)
+#define RSETUP(x) ((x) << RSETUP_SHIFT)
+#define WHOLD(x) ((x) << WHOLD_SHIFT)
+#define WSTROBE(x) ((x) << WSTROBE_SHIFT)
+#define WSETUP(x) ((x) << WSETUP_SHIFT)
+#define EW(x) ((x) << EW_SHIFT)
+#define SS(x) ((x) << SS_SHIFT)
+
Can you not use BIT(*) directly instead above magics
+#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 TA_VAL(x) (((x) & TA(TA_MAX)) >> TA_SHIFT)
+#define RHOLD_VAL(x) (((x) & RHOLD(RHOLD_MAX)) >> RHOLD_SHIFT)
+#define RSTROBE_VAL(x) (((x) & RSTROBE(RSTROBE_MAX)) >> RSTROBE_SHIFT)
+#define RSETUP_VAL(x) (((x) & RSETUP(RSETUP_MAX)) >> RSETUP_SHIFT)
+#define WHOLD_VAL(x) (((x) & WHOLD(WHOLD_MAX)) >> WHOLD_SHIFT)
+#define WSTROBE_VAL(x) (((x) & WSTROBE(WSTROBE_MAX)) >> WSTROBE_SHIFT)
+#define WSETUP_VAL(x) (((x) & WSETUP(WSETUP_MAX)) >> WSETUP_SHIFT)
+#define EW_VAL(x) (((x) & EW(EW_MAX)) >> EW_SHIFT)
+#define SS_VAL(x) (((x) & SS(SS_MAX)) >> SS_SHIFT)
+
Same here..
+
+#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)
+
This mask is next to impossible if reviewer needs to decode it.
+#define DRV_NAME "davinci-aemif"
+
+struct aemif_device {
+ struct davinci_aemif_pdata *cfg;
+ void __iomem *base;
+ struct clk *clk;
+ /* clock rate in KHz */
+ unsigned long clk_rate;
+};
+
+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;
+
don't break if--else with un-ncessary new line here.
+ /* ... 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;
+ u32 set, val;
+
+ if (!data)
+ return -EINVAL;
+
+ ta = aemif_calc_rate(data->ta, aemif->clk_rate, TA_MAX);
+ rhold = aemif_calc_rate(data->rhold, aemif->clk_rate, RHOLD_MAX);
+ rstrobe = aemif_calc_rate(data->rstrobe, aemif->clk_rate, RSTROBE_MAX);
+ rsetup = aemif_calc_rate(data->rsetup, aemif->clk_rate, RSETUP_MAX);
+ whold = aemif_calc_rate(data->whold, aemif->clk_rate, WHOLD_MAX);
+ wstrobe = aemif_calc_rate(data->wstrobe, aemif->clk_rate, WSTROBE_MAX);
+ wsetup = aemif_calc_rate(data->wsetup, aemif->clk_rate, 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;
+}
+
+inline int aemif_cycles_to_nsec(int val)
+{
+ return (val * NSEC_PER_MSEC) / aemif->clk_rate;
+}
+
+/**
+ * davinci_aemif_get_hw_params - function to read hw register values
+ * @cs: chip select
+ * @data: ptr to cs data
+ *
+ * This function reads the defaults from the registers and update
+ * the timing values. Required for get/set commands and also for
+ * the case when driver needs to use defaults in hardware.
+ */
+static void davinci_aemif_get_hw_params(int cs,
+ struct davinci_aemif_cs_data *data)
+{
+ u32 val, offset = A1CR_OFFSET + cs * 4;
+
+ val = readl(aemif->base + offset);
+ data->ta = aemif_cycles_to_nsec(TA_VAL(val));
+ data->rhold = aemif_cycles_to_nsec(RHOLD_VAL(val));
+ data->rstrobe = aemif_cycles_to_nsec(RSTROBE_VAL(val));
+ data->rsetup = aemif_cycles_to_nsec(RSETUP_VAL(val));
+ data->whold = aemif_cycles_to_nsec(WHOLD_VAL(val));
+ data->wstrobe = aemif_cycles_to_nsec(WSTROBE_VAL(val));
+ data->wsetup = aemif_cycles_to_nsec(WSETUP_VAL(val));
+ data->enable_ew = EW_VAL(val);
+ data->enable_ss = SS_VAL(val);
+ data->asize = val & ASIZE_MAX;
+}
+
+/**
+ * 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 */
what is chip CS ? you can either use CS or chip select..
+ chip_cs = cs + 2;
Use a macro like AEMIF_CS_START instead of hardcoding it.
+
+ curr_cs_data = get_cs_data(chip_cs);
+ if (curr_cs_data) {
+ /* for configuration we use cs since it is used to index ACR */
+ 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);
+
Who is the user of this EXPORT ?
+/**
+ * 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);
+
This one too.
[...]
+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");
Please use dev attributes. Above usage of clk_get isn't recommonded
in drivers. You might have to add alias entries in your clock data for
it to work though.
+ if (IS_ERR(aemif->clk))
+ return PTR_ERR(aemif->clk);
+
+ clk_prepare_enable(aemif->clk);
+ aemif->clk_rate = clk_get_rate(aemif->clk) / 1000;
+
/1000 for what ? Converting it into KHz ?
+ 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;
+ }
+
+ 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;
+ }
+
+ for (i = 0; i < cfg->num_cs; i++) {
+ /* cs is from 2-5. Internally we use cs-2 to access ACR */
+ ret = davinci_aemif_config_abus(cfg->cs_data[i].cs - 2,
+ 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 0;
+error:
+ clk_disable_unprepare(aemif->clk);
+ clk_put(aemif->clk);
Alos unmap 'aemif->base' here..
+ 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 <m-karicheri2@xxxxxx>");
+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/
+ *
s/2010/2012
+ * 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
Fix the header guard as per new directory
Regards
Santosh
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
