[PATCH v4 4/4] memory: emif: add device tree support to emif driver
Shilimkar, Santosh
santosh.shilimkar at ti.com
Mon Jul 2 09:18:18 EDT 2012
On Sat, Jun 30, 2012 at 10:12 AM, Shilimkar, Santosh
<santosh.shilimkar at ti.com> wrote:
> On Sat, Jun 30, 2012 at 9:53 AM, Greg KH <gregkh at linuxfoundation.org> wrote:
>> On Sat, Jun 30, 2012 at 09:38:41AM +0530, Shilimkar, Santosh wrote:
>>> (+ Greg, By mistake the your name got dropped cc from list)
>>>
>>> On Fri, Jun 29, 2012 at 7:13 PM, Santosh Shilimkar
>>> <santosh.shilimkar at ti.com> wrote:
>>> > From: Aneesh V <aneesh at ti.com>
>>> >
>>> > Device tree support for the EMIF driver.
>>> >
>>> > Reviewed-by: Benoit Cousson <b-cousson at ti.com>
>>> > Reviewed-by: Grant Likely <grant.likely at secretlab.ca>
>>> > Tested-by: Lokesh Vutla <lokeshvutla at ti.com>
>>> > Signed-off-by: Aneesh V <aneesh at ti.com>
>>> > [santosh.shilimkar at ti.com: Rebased against 3.5-rc]
>>> > Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
>>> > ---
>>> > drivers/memory/emif.c | 291 ++++++++++++++++++++++++++++++++++++++++++++++++-
>>> > 1 file changed, 290 insertions(+), 1 deletion(-)
>>
>> Wouldn't this just be better off as a separate file that only gets build
>> if CONFIG_OF is set, as I'm sure that other systems are going to want
>> access to these "read the device tree values" functions, right?
>>
> Probably yes. At least separate the LPDDR2 memory
> generic parameter DT read code. There are parameters like phy
> type which is specific to OMAP controllers so that still need to kept
> inside EMIF driver. So there in driver, few lines of code will be there
> under CONFIG_OF.
>
> I can extract those functions which can be commonly used and put them
> in another file under drivers/memory/
>
> Is that fine with you ?
>
To elaborate more, I have created below patch.
Let me know what do you think ?
------>>
>From 42abb2b29136efb9983abdd203fe1e6bce784715 Mon Sep 17 00:00:00 2001
From: Aneesh V <aneesh at ti.com>
Date: Mon, 30 Jan 2012 20:06:30 +0530
Subject: [PATCH] memory: emif: add device tree support to emif driver
Device tree support for the EMIF driver. LPDDR2 generic timings
extraction from device is managed using couple of helper
functions which can be used by other memory controller
drivers.
Reviewed-by: Benoit Cousson <b-cousson at ti.com>
Reviewed-by: Grant Likely <grant.likely at secretlab.ca>
Tested-by: Lokesh Vutla <lokeshvutla at ti.com>
Signed-off-by: Aneesh V <aneesh at ti.com>
[santosh.shilimkar at ti.com: Rebased against 3.5-rc]
Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
>From last version, the only change is to the lpddr2 dt timings generic
functions moved to separate file(of_memory.c) and build it only for
CONFIG_OF.
drivers/memory/Makefile | 1 +
drivers/memory/emif.c | 182 +++++++++++++++++++++++++++++++++++++++++++-
drivers/memory/of_memory.c | 153 +++++++++++++++++++++++++++++++++++++
drivers/memory/of_memory.h | 36 +++++++++
4 files changed, 371 insertions(+), 1 deletions(-)
create mode 100644 drivers/memory/of_memory.c
create mode 100644 drivers/memory/of_memory.h
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 42b3ce9..cd8486b 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -2,6 +2,7 @@
# Makefile for memory devices
#
+obj-$(CONFIG_OF) += of_memory.o
obj-$(CONFIG_TI_EMIF) += emif.o
obj-$(CONFIG_TEGRA20_MC) += tegra20-mc.o
obj-$(CONFIG_TEGRA30_MC) += tegra30-mc.o
diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c
index 33a4396..06b4eb7 100644
--- a/drivers/memory/emif.c
+++ b/drivers/memory/emif.c
@@ -18,6 +18,7 @@
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
+#include <linux/of.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/module.h>
@@ -25,6 +26,7 @@
#include <linux/spinlock.h>
#include <memory/jedec_ddr.h>
#include "emif.h"
+#include "of_memory.h"
/**
* struct emif_data - Per device static data for driver's use
@@ -49,6 +51,7 @@
* frequency in effect at the moment)
* @plat_data: Pointer to saved platform data.
* @debugfs_root: dentry to the root folder for EMIF in debugfs
+ * @np_ddr: Pointer to ddr device tree node
*/
struct emif_data {
u8 duplicate;
@@ -63,6 +66,7 @@ struct emif_data {
struct emif_regs *curr_regs;
struct emif_platform_data *plat_data;
struct dentry *debugfs_root;
+ struct device_node *np_ddr;
};
static struct emif_data *emif1;
@@ -1148,6 +1152,168 @@ static int is_custom_config_valid(struct
emif_custom_configs *cust_cfgs,
return valid;
}
+#if defined(CONFIG_OF)
+static void __init_or_module of_get_custom_configs(struct device_node *np_emif,
+ struct emif_data *emif)
+{
+ struct emif_custom_configs *cust_cfgs = NULL;
+ int len;
+ const int *lpmode, *poll_intvl;
+
+ lpmode = of_get_property(np_emif, "low-power-mode", &len);
+ poll_intvl = of_get_property(np_emif, "temp-alert-poll-interval", &len);
+
+ if (lpmode || poll_intvl)
+ cust_cfgs = devm_kzalloc(emif->dev, sizeof(*cust_cfgs),
+ GFP_KERNEL);
+
+ if (!cust_cfgs)
+ return;
+
+ if (lpmode) {
+ cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_LPMODE;
+ cust_cfgs->lpmode = *lpmode;
+ of_property_read_u32(np_emif,
+ "low-power-mode-timeout-performance",
+ &cust_cfgs->lpmode_timeout_performance);
+ of_property_read_u32(np_emif,
+ "low-power-mode-timeout-power",
+ &cust_cfgs->lpmode_timeout_power);
+ of_property_read_u32(np_emif,
+ "low-power-mode-freq-threshold",
+ &cust_cfgs->lpmode_freq_threshold);
+ }
+
+ if (poll_intvl) {
+ cust_cfgs->mask |=
+ EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL;
+ cust_cfgs->temp_alert_poll_interval_ms = *poll_intvl;
+ }
+
+ if (!is_custom_config_valid(cust_cfgs, emif->dev)) {
+ devm_kfree(emif->dev, cust_cfgs);
+ return;
+ }
+
+ emif->plat_data->custom_configs = cust_cfgs;
+}
+
+static void __init_or_module of_get_ddr_info(struct device_node *np_emif,
+ struct device_node *np_ddr,
+ struct ddr_device_info *dev_info)
+{
+ u32 density = 0, io_width = 0;
+ int len;
+
+ if (of_find_property(np_emif, "cs1-used", &len))
+ dev_info->cs1_used = true;
+
+ if (of_find_property(np_emif, "cal-resistor-per-cs", &len))
+ dev_info->cal_resistors_per_cs = true;
+
+ if (of_device_is_compatible(np_ddr , "jedec,lpddr2-s4"))
+ dev_info->type = DDR_TYPE_LPDDR2_S4;
+ else if (of_device_is_compatible(np_ddr , "jedec,lpddr2-s2"))
+ dev_info->type = DDR_TYPE_LPDDR2_S2;
+
+ of_property_read_u32(np_ddr, "density", &density);
+ of_property_read_u32(np_ddr, "io-width", &io_width);
+
+ /* Convert from density in Mb to the density encoding in jedc_ddr.h */
+ if (density & (density - 1))
+ dev_info->density = 0;
+ else
+ dev_info->density = __fls(density) - 5;
+
+ /* Convert from io_width in bits to io_width encoding in jedc_ddr.h */
+ if (io_width & (io_width - 1))
+ dev_info->io_width = 0;
+ else
+ dev_info->io_width = __fls(io_width) - 1;
+}
+
+static struct emif_data * __init_or_module of_get_device_details(
+ struct device_node *np_emif, struct device *dev)
+{
+ struct emif_data *emif = NULL;
+ struct ddr_device_info *dev_info = NULL;
+ struct emif_platform_data *pd = NULL;
+ struct device_node *np_ddr;
+ int len;
+
+ np_ddr = of_parse_phandle(np_emif, "device-handle", 0);
+ if (!np_ddr)
+ goto error;
+ emif = devm_kzalloc(dev, sizeof(struct emif_data), GFP_KERNEL);
+ pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+ dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
+
+ if (!emif || !pd || !dev_info) {
+ dev_err(dev, "%s: of_get_device_details() failure!!\n",
+ __func__);
+ goto error;
+ }
+
+ emif->plat_data = pd;
+ pd->device_info = dev_info;
+ emif->dev = dev;
+ emif->np_ddr = np_ddr;
+ emif->temperature_level = SDRAM_TEMP_NOMINAL;
+
+ if (of_device_is_compatible(np_emif, "ti,emif-4d"))
+ emif->plat_data->ip_rev = EMIF_4D;
+ else if (of_device_is_compatible(np_emif, "ti,emif-4d5"))
+ emif->plat_data->ip_rev = EMIF_4D5;
+
+ of_property_read_u32(np_emif, "phy-type", &pd->phy_type);
+
+ if (of_find_property(np_emif, "hw-caps-ll-interface", &len))
+ pd->hw_caps |= EMIF_HW_CAPS_LL_INTERFACE;
+
+ of_get_ddr_info(np_emif, np_ddr, dev_info);
+ if (!is_dev_data_valid(pd->device_info->type, pd->device_info->density,
+ pd->device_info->io_width, pd->phy_type, pd->ip_rev,
+ emif->dev)) {
+ dev_err(dev, "%s: invalid device data!!\n", __func__);
+ goto error;
+ }
+ /*
+ * For EMIF instances other than EMIF1 see if the devices connected
+ * are exactly same as on EMIF1(which is typically the case). If so,
+ * mark it as a duplicate of EMIF1. This will save some memory and
+ * computation.
+ */
+ if (emif1 && emif1->np_ddr == np_ddr) {
+ emif->duplicate = true;
+ goto out;
+ } else if (emif1) {
+ dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
+ __func__);
+ }
+
+ of_get_custom_configs(np_emif, emif);
+ emif->plat_data->timings = of_get_ddr_timings(np_ddr, emif->dev,
+ emif->plat_data->device_info->type,
+ &emif->plat_data->timings_arr_size);
+
+ emif->plat_data->min_tck = of_get_min_tck(np_ddr, emif->dev);
+ goto out;
+
+error:
+ return NULL;
+out:
+ return emif;
+}
+
+#else
+
+static struct emif_data * __init_or_module of_get_device_details(
+ struct device_node *np_emif, struct device *dev)
+{
+ return NULL;
+}
+#endif
+
static struct emif_data *__init_or_module get_device_details(
struct platform_device *pdev)
{
@@ -1267,7 +1433,11 @@ static int __init_or_module emif_probe(struct
platform_device *pdev)
struct resource *res;
int irq;
- emif = get_device_details(pdev);
+ if (pdev->dev.of_node)
+ emif = of_get_device_details(pdev->dev.of_node, &pdev->dev);
+ else
+ emif = get_device_details(pdev);
+
if (!emif) {
pr_err("%s: error getting device data\n", __func__);
goto error;
@@ -1644,11 +1814,21 @@ static void __attribute__((unused))
freq_post_notify_handling(void)
spin_unlock_irqrestore(&emif_lock, irq_state);
}
+#if defined(CONFIG_OF)
+static const struct of_device_id emif_of_match[] = {
+ { .compatible = "ti,emif-4d" },
+ { .compatible = "ti,emif-4d5" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, emif_of_match);
+#endif
+
static struct platform_driver emif_driver = {
.remove = __exit_p(emif_remove),
.shutdown = emif_shutdown,
.driver = {
.name = "emif",
+ .of_match_table = of_match_ptr(emif_of_match),
},
};
diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c
new file mode 100644
index 0000000..c16aacc
--- /dev/null
+++ b/drivers/memory/of_memory.c
@@ -0,0 +1,153 @@
+/*
+ * OpenFirmware helpers for memory drivers
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/gfp.h>
+#include <memory/jedec_ddr.h>
+#include <linux/export.h>
+
+/**
+ * of_get_min_tck() - extract min timing values for ddr
+ * @np: pointer to ddr device tree node
+ * @device: device requesting for min timing values
+ *
+ * Populates the lpddr2_min_tck structure by extracting data
+ * from device tree node. Returns a pointer to the populated
+ * structure. If any error in populating the structure, returns
+ * default min timings provided by JEDEC.
+ */
+const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
+ struct device *dev)
+{
+ int ret = 0;
+ struct lpddr2_min_tck *min;
+
+ min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL);
+ if (!min)
+ goto default_min_tck;
+
+ ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab);
+ ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD);
+ ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR);
+ ret |= of_property_read_u32(np, "tRASmin-min-tck", &min->tRASmin);
+ ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD);
+ ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR);
+ ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP);
+ ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP);
+ ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE);
+ ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR);
+ ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW);
+
+ if (ret) {
+ devm_kfree(dev, min);
+ goto default_min_tck;
+ }
+
+ return min;
+
+default_min_tck:
+ dev_warn(dev, "%s: using default min-tck values\n", __func__);
+ return &lpddr2_jedec_min_tck;
+}
+EXPORT_SYMBOL(of_get_min_tck);
+
+static int of_do_get_timings(struct device_node *np,
+ struct lpddr2_timings *tim)
+{
+ int ret;
+
+ ret = of_property_read_u32(np, "max-freq", &tim->max_freq);
+ ret |= of_property_read_u32(np, "min-freq", &tim->min_freq);
+ ret |= of_property_read_u32(np, "tRPab", &tim->tRPab);
+ ret |= of_property_read_u32(np, "tRCD", &tim->tRCD);
+ ret |= of_property_read_u32(np, "tWR", &tim->tWR);
+ ret |= of_property_read_u32(np, "tRAS-min", &tim->tRAS_min);
+ ret |= of_property_read_u32(np, "tRRD", &tim->tRRD);
+ ret |= of_property_read_u32(np, "tWTR", &tim->tWTR);
+ ret |= of_property_read_u32(np, "tXP", &tim->tXP);
+ ret |= of_property_read_u32(np, "tRTP", &tim->tRTP);
+ ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR);
+ ret |= of_property_read_u32(np, "tDQSCK-max", &tim->tDQSCK_max);
+ ret |= of_property_read_u32(np, "tFAW", &tim->tFAW);
+ ret |= of_property_read_u32(np, "tZQCS", &tim->tZQCS);
+ ret |= of_property_read_u32(np, "tZQCL", &tim->tZQCL);
+ ret |= of_property_read_u32(np, "tZQinit", &tim->tZQinit);
+ ret |= of_property_read_u32(np, "tRAS-max-ns", &tim->tRAS_max_ns);
+ ret |= of_property_read_u32(np, "tDQSCK-max-derated",
+ &tim->tDQSCK_max_derated);
+
+ return ret;
+}
+
+/**
+ * of_get_ddr_timings() - extracts the ddr timings and updates no of
+ * frequencies available.
+ * @np_ddr: Pointer to ddr device tree node
+ * @dev: Device requesting for ddr timings
+ * @device_type: Type of ddr(LPDDR2 S2/S4)
+ * @nr_frequencies: No of frequencies available for ddr
+ * (updated by this function)
+ *
+ * Populates lpddr2_timings structure by extracting data from device
+ * tree node. Returns pointer to populated structure. If any error
+ * while populating, returns default timings provided by JEDEC.
+ */
+const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr,
+ struct device *dev, u32 device_type, u32 *nr_frequencies)
+{
+ struct lpddr2_timings *timings = NULL;
+ u32 arr_sz = 0, i = 0;
+ struct device_node *np_tim;
+ char *tim_compat;
+
+ switch (device_type) {
+ case DDR_TYPE_LPDDR2_S2:
+ case DDR_TYPE_LPDDR2_S4:
+ tim_compat = "jedec,lpddr2-timings";
+ break;
+ default:
+ dev_warn(dev, "%s: un-supported memory type\n", __func__);
+ }
+
+ for_each_child_of_node(np_ddr, np_tim)
+ if (of_device_is_compatible(np_tim, tim_compat))
+ arr_sz++;
+
+ if (arr_sz)
+ timings = devm_kzalloc(dev, sizeof(*timings) * arr_sz,
+ GFP_KERNEL);
+
+ if (!timings)
+ goto default_timings;
+
+ for_each_child_of_node(np_ddr, np_tim) {
+ if (of_device_is_compatible(np_tim, tim_compat)) {
+ if (of_do_get_timings(np_tim, &timings[i])) {
+ devm_kfree(dev, timings);
+ goto default_timings;
+ }
+ i++;
+ }
+ }
+
+ *nr_frequencies = arr_sz;
+
+ return timings;
+
+default_timings:
+ dev_warn(dev, "%s: using default timings\n", __func__);
+ *nr_frequencies = ARRAY_SIZE(lpddr2_jedec_timings);
+ return lpddr2_jedec_timings;
+}
+EXPORT_SYMBOL(of_get_ddr_timings);
diff --git a/drivers/memory/of_memory.h b/drivers/memory/of_memory.h
new file mode 100644
index 0000000..20b496e
--- /dev/null
+++ b/drivers/memory/of_memory.h
@@ -0,0 +1,36 @@
+/*
+ * OpenFirmware helpers for memory drivers
+ *
+ * Copyright (C) 2012 Texas Instruments, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_MEMORY_OF_REG_H
+#define __LINUX_MEMORY_OF_REG_H
+
+#ifdef CONFIG_OF
+extern const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np,
+ struct device *dev);
+extern const struct lpddr2_timings
+ *of_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
+ u32 device_type, u32 *nr_frequencies);
+#else
+static inline const struct lpddr2_min_tck
+ *of_get_min_tck(struct device_node *np, struct device *dev)
+{
+ return NULL;
+}
+
+static inline const struct lpddr2_timings
+ *of_get_ddr_timings(struct device_node *np_ddr, struct device *dev,
+ u32 device_type, u32 *nr_frequencies)
+{
+ return NULL;
+}
+#endif /* CONFIG_OF */
+
+#endif /* __LINUX_MEMORY_OF_REG_ */
--
1.7.5.4
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