[PATCH v6 12/17] spi: dw: Add support for AMD Pensando Elba SoC

[Larson, Bradley]

On 8/21/22 11:18 AM, Serge Semin wrote:
> On Sat, Aug 20, 2022 at 12:57:45PM -0700, Brad Larson wrote:
>> From: Brad Larson <blarson at amd.com>
>>
>> The AMD Pensando Elba SoC includes a DW apb_ssi v4 controller
>> with device specific chip-select control.  The Elba SoC
>> provides four chip-selects where the native DW IP supports
>> two chip-selects.  The Elba DW_SPI instance has two native
>> CS signals that are always overridden.
>>
>> Signed-off-by: Brad Larson <blarson at amd.com>
>> ---
>>   drivers/spi/spi-dw-mmio.c | 77 +++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 77 insertions(+)
>>
>> diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
>> index 26c40ea6dd12..36b8c5e10bb3 100644
>> --- a/drivers/spi/spi-dw-mmio.c
>> +++ b/drivers/spi/spi-dw-mmio.c
>> @@ -53,6 +53,24 @@ struct dw_spi_mscc {
>>        void __iomem        *spi_mst; /* Not sparx5 */
>>   };
>>
>> +struct dw_spi_elba {
>> +     struct regmap *syscon;
>> +};
>> +
>> +/*
>> + * Elba SoC does not use ssi, pin override is used for cs 0,1 and
>> + * gpios for cs 2,3 as defined in the device tree.
>> + *
>> + * cs:  |       1               0
>> + * bit: |---3-------2-------1-------0
>> + *      |  cs1   cs1_ovr   cs0   cs0_ovr
>> + */
>> +#define ELBA_SPICS_REG                       0x2468
>> +#define ELBA_SPICS_SHIFT(cs)         (2 * (cs))
>> +#define ELBA_SPICS_MASK(cs)          (0x3 << ELBA_SPICS_SHIFT(cs))
>> +#define ELBA_SPICS_SET(cs, val)      \
>> +                     ((((val) << 1) | 0x1) << ELBA_SPICS_SHIFT(cs))
> Please take the @Andy' notes into account:
> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flore.kernel.org%2Flkml%2FCAHp75Vex0VkECYd%3DkY0m6%3DjXBYSXg2UFu7vn271%2BQ49WZn22GA%40mail.gmail.com%2F&data=05%7C01%7CBradley.Larson%40amd.com%7C25d0f17dfcbd44f661c808da83a19a98%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637967027418603429%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=VFI%2FptM79YYbZm%2FyQmtssLsNIQ75AOU05ronZ1QStlU%3D&reserved=0

Yes, I had a tested change for this but missed adding to the patch update.
This is the change and I'll resend just this patch.

--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -66,10 +66,6 @@ struct dw_spi_elba {
   *      |  cs1   cs1_ovr   cs0   cs0_ovr
   */
  #define ELBA_SPICS_REG 0x2468
-#define ELBA_SPICS_SHIFT(cs)           (2 * (cs))
-#define ELBA_SPICS_MASK(cs)            (0x3 << ELBA_SPICS_SHIFT(cs))
-#define ELBA_SPICS_SET(cs, val)        \
-                       ((((val) << 1) | 0x1) << ELBA_SPICS_SHIFT(cs))

  /*
   * The Designware SPI controller (referred to as master in the 
documentation)
@@ -257,8 +253,9 @@ static int dw_spi_canaan_k210_init(struct 
platform_device *pdev,

  static void dw_spi_elba_override_cs(struct dw_spi_elba *dwselba, int 
cs, int enable)
  {
- regmap_update_bits(dwselba->syscon, ELBA_SPICS_REG, ELBA_SPICS_MASK(cs),
-                          ELBA_SPICS_SET(cs, enable));
+ regmap_update_bits(dwselba->syscon, ELBA_SPICS_REG,
+                          (GENMASK(1, 0) << ((cs) << 1)),
+                          ((enable) << 1 | BIT(0)) << ((cs) << 1));

  }

> One more nitpick below.
>
> +static int dw_spi_elba_init(struct platform_device *pdev,
> +                         struct dw_spi_mmio *dwsmmio)
> +{
> +     const char *syscon_name = "amd,pensando-elba-syscon";
> +     struct device_node *np = pdev->dev.of_node;
>> +     struct device_node *node;
>> +     struct dw_spi_elba *dwselba;
> Please, use the reverse xmas tree order of the local variables
> as the rest of the driver mainly implies.
Changed to reverse xmas tree ordering.

Regards,
Brad