Greg,
On Mon, Jul 2, 2012 at 6:48 PM, Shilimkar, Santosh
<santosh.shilimkar@xxxxxx> wrote:
> On Sat, Jun 30, 2012 at 10:12 AM, Shilimkar, Santosh
> <santosh.shilimkar@xxxxxx> wrote:
>> On Sat, Jun 30, 2012 at 9:53 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 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@xxxxxx> wrote:
>>>> > From: Aneesh V <aneesh@xxxxxx>
>>>> >
>>>> > Device tree support for the EMIF driver.
>>>> >
>>>> > Reviewed-by: Benoit Cousson <b-cousson@xxxxxx>
>>>> > Reviewed-by: Grant Likely <grant.likely@xxxxxxxxxxxx>
>>>> > Tested-by: Lokesh Vutla <lokeshvutla@xxxxxx>
>>>> > Signed-off-by: Aneesh V <aneesh@xxxxxx>
>>>> > [santosh.shilimkar@xxxxxx: Rebased against 3.5-rc]
>>>> > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
>>>> > ---
>>>> > 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 ?
>
Any comments ??
> ------>>
> From 42abb2b29136efb9983abdd203fe1e6bce784715 Mon Sep 17 00:00:00 2001
> From: Aneesh V <aneesh@xxxxxx>
> 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@xxxxxx>
> Reviewed-by: Grant Likely <grant.likely@xxxxxxxxxxxx>
> Tested-by: Lokesh Vutla <lokeshvutla@xxxxxx>
> Signed-off-by: Aneesh V <aneesh@xxxxxx>
> [santosh.shilimkar@xxxxxx: Rebased against 3.5-rc]
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> 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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