[PATCH v4 4/4] memory: emif: add device tree support to emif driver

[Shilimkar, Santosh]

On Fri, Aug 17, 2012 at 12:15 AM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Mon, Aug 13, 2012 at 10:57:06AM +0530, Shilimkar, Santosh wrote:
>> Greg,
>>
>> On Wed, Jul 18, 2012 at 12:14 PM, Shilimkar, Santosh
>> <santosh.shilimkar at ti.com> wrote:
>> > On Tue, Jul 17, 2012 at 11:28 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
>> >> On Tue, Jul 17, 2012 at 10:37:45PM +0530, Shilimkar, Santosh wrote:
>> >>> On Tue, Jul 17, 2012 at 10:06 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
>> >>> > On Mon, Jul 09, 2012 at 07:02:36PM +0530, Shilimkar, Santosh wrote:
>> >>> >> Greg,
>> >>> >>
>> >
>> > [..]
>> >
>> >>> >From 74688a87fd490909e9122bf757c0096480e9fc11 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 4/4] 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>
>> >>> Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
>> >>> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
>> >>> ---
>> >>>  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 deletion(-)
>> >>>  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)
>> >>
>> >> Why can't all of this code be in the of_memory.c file?
>> >>
>> > Primarily because the parameters are very much specific to EMIF
>> > memory controller and won't be of much use for other memory controllers.
>> >
>> > Currently the information extracted from DT with these function is like:
>> > - EMIF controller IP version : EMIF_4D or EMIF_4D5
>> > - Which analog phy is integrated : EMIF_ATTILAPHY or EMIF_ATTILAPHY
>> > - IP hardware interface: EMIF Low latency port or sys port interface.
>> > - EMIF connections - Whether EMIF1 only, EMIF2 only or EMIF1 & EMIF2
>> > - Memory connections to EMIF - Same type and size memories or asymmetric
>> > - Chip select usage per controller: Whether CS0, CS1, CS0 & CS1
>> > - ZQ calibration - Per chip select or enable EMIF dual calibration feature.
>> > - Enable/disable EMIF Low power mode and temperature alerts.
>> > - EMIF low power mode configuration:
>> >       - Clock stop, self refresh, Deep power down.
>> >       - Low power time out values for performance and power mode.
>> >       - DDR frequency threshold to switch between power and
>> > performance settings.
>> > - EMIF temperature polling cycle configuration.
>> >
>> > As you can see these are very specific to the EMIF memory controller and hence
>> > I didn't move them to of_memory.c
>> >
>> Do you have any more comment on this patch? If not, I can go ahead and
>> post the refreshed version of the patch.
>
> Please always do, I have no idea what this patch even contained anymore,
> it was a few hundred patches ago that I've reviewed and I have no
> recollection of it...
>
Done. Posted the refresh version [1]. Thanks for review.

Regards
Santosh

[1] https://patchwork.kernel.org/patch/1337871/