Re: [PATCH 1/3] phy: zynqmp: Store instance instead of type

From: Sean Anderson
Date: Thu Apr 25 2024 - 11:28:31 EST


On 4/24/24 02:38, Michal Simek wrote:
>
>
> On 4/23/24 17:02, Sean Anderson wrote:
>> On 4/23/24 02:25, Michal Simek wrote:
>>>
>>>
>>> On 4/22/24 20:58, Sean Anderson wrote:
>>>> The phy "type" is just the combination of protocol and instance, and is
>>>> never used apart from that. Store the instance directly, instead of
>>>> converting to a type first. No functional change intended.
>>>>
>>>> Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxxx>
>>>> ---
>>>>
>>>> drivers/phy/xilinx/phy-zynqmp.c | 107 +++++++-------------------------
>>>> 1 file changed, 24 insertions(+), 83 deletions(-)
>>>>
>>>> diff --git a/drivers/phy/xilinx/phy-zynqmp.c b/drivers/phy/xilinx/phy-zynqmp.c
>>>> index f72c5257d712..b507ed4c3053 100644
>>>> --- a/drivers/phy/xilinx/phy-zynqmp.c
>>>> +++ b/drivers/phy/xilinx/phy-zynqmp.c
>>>> @@ -146,22 +146,6 @@
>>>> /* Total number of controllers */
>>>> #define CONTROLLERS_PER_LANE 5
>>>> -/* Protocol Type parameters */
>>>> -#define XPSGTR_TYPE_USB0 0 /* USB controller 0 */
>>>> -#define XPSGTR_TYPE_USB1 1 /* USB controller 1 */
>>>> -#define XPSGTR_TYPE_SATA_0 2 /* SATA controller lane 0 */
>>>> -#define XPSGTR_TYPE_SATA_1 3 /* SATA controller lane 1 */
>>>> -#define XPSGTR_TYPE_PCIE_0 4 /* PCIe controller lane 0 */
>>>> -#define XPSGTR_TYPE_PCIE_1 5 /* PCIe controller lane 1 */
>>>> -#define XPSGTR_TYPE_PCIE_2 6 /* PCIe controller lane 2 */
>>>> -#define XPSGTR_TYPE_PCIE_3 7 /* PCIe controller lane 3 */
>>>> -#define XPSGTR_TYPE_DP_0 8 /* Display Port controller lane 0 */
>>>> -#define XPSGTR_TYPE_DP_1 9 /* Display Port controller lane 1 */
>>>> -#define XPSGTR_TYPE_SGMII0 10 /* Ethernet SGMII controller 0 */
>>>> -#define XPSGTR_TYPE_SGMII1 11 /* Ethernet SGMII controller 1 */
>>>> -#define XPSGTR_TYPE_SGMII2 12 /* Ethernet SGMII controller 2 */
>>>> -#define XPSGTR_TYPE_SGMII3 13 /* Ethernet SGMII controller 3 */
>>>> -
>>>> /* Timeout values */
>>>> #define TIMEOUT_US 1000
>>>> @@ -184,7 +168,8 @@ struct xpsgtr_ssc {
>>>> /**
>>>> * struct xpsgtr_phy - representation of a lane
>>>> * @phy: pointer to the kernel PHY device
>>>> - * @type: controller which uses this lane
>>>> + * @instance: instance of the protocol type (such as the lane within a
>>>> + * protocol, or the USB/Ethernet controller)
>>>> * @lane: lane number
>>>> * @protocol: protocol in which the lane operates
>>>> * @skip_phy_init: skip phy_init() if true
>>>> @@ -193,7 +178,7 @@ struct xpsgtr_ssc {
>>>> */
>>>> struct xpsgtr_phy {
>>>> struct phy *phy;
>>>> - u8 type;
>>>> + u8 instance;
>>>> u8 lane;
>>>> u8 protocol;
>>>> bool skip_phy_init;
>>>> @@ -330,8 +315,8 @@ static int xpsgtr_wait_pll_lock(struct phy *phy)
>>>> if (ret == -ETIMEDOUT)
>>>> dev_err(gtr_dev->dev,
>>>> - "lane %u (type %u, protocol %u): PLL lock timeout\n",
>>>> - gtr_phy->lane, gtr_phy->type, gtr_phy->protocol);
>>>> + "lane %u (protocol %u, instance %u): PLL lock timeout\n",
>>>> + gtr_phy->lane, gtr_phy->protocol, gtr_phy->instance);
>>>> return ret;
>>>> }
>>>> @@ -643,8 +628,7 @@ static int xpsgtr_phy_power_on(struct phy *phy)
>>>> * cumulating waits for both lanes. The user is expected to initialize
>>>> * lane 0 last.
>>>> */
>>>> - if (gtr_phy->protocol != ICM_PROTOCOL_DP ||
>>>> - gtr_phy->type == XPSGTR_TYPE_DP_0)
>>>> + if (gtr_phy->protocol != ICM_PROTOCOL_DP || !gtr_phy->instance)
>>>> ret = xpsgtr_wait_pll_lock(phy);
>>>> return ret;
>>>> @@ -674,73 +658,33 @@ static const struct phy_ops xpsgtr_phyops = {
>>>> * OF Xlate Support
>>>> */
>>>> -/* Set the lane type and protocol based on the PHY type and instance number. */
>>>> +/* Set the lane protocol and instance based on the PHY type and instance number. */
>>>> static int xpsgtr_set_lane_type(struct xpsgtr_phy *gtr_phy, u8 phy_type,
>>>> unsigned int phy_instance)
>>>> {
>>>> unsigned int num_phy_types;
>>>> - const int *phy_types;
>>>> switch (phy_type) {
>>>> - case PHY_TYPE_SATA: {
>>>> - static const int types[] = {
>>>> - XPSGTR_TYPE_SATA_0,
>>>> - XPSGTR_TYPE_SATA_1,
>>>> - };
>>>> -
>>>> - phy_types = types;
>>>> - num_phy_types = ARRAY_SIZE(types);
>>>> + case PHY_TYPE_SATA:
>>>> + num_phy_types = 2;
>>>> gtr_phy->protocol = ICM_PROTOCOL_SATA;
>>>> break;
>>>> - }
>>>> - case PHY_TYPE_USB3: {
>>>> - static const int types[] = {
>>>> - XPSGTR_TYPE_USB0,
>>>> - XPSGTR_TYPE_USB1,
>>>> - };
>>>> -
>>>> - phy_types = types;
>>>> - num_phy_types = ARRAY_SIZE(types);
>>>> + case PHY_TYPE_USB3:
>>>> + num_phy_types = 2;
>>>> gtr_phy->protocol = ICM_PROTOCOL_USB;
>>>> break;
>>>> - }
>>>> - case PHY_TYPE_DP: {
>>>> - static const int types[] = {
>>>> - XPSGTR_TYPE_DP_0,
>>>> - XPSGTR_TYPE_DP_1,
>>>> - };
>>>> -
>>>> - phy_types = types;
>>>> - num_phy_types = ARRAY_SIZE(types);
>>>> + case PHY_TYPE_DP:
>>>> + num_phy_types = 2;
>>>> gtr_phy->protocol = ICM_PROTOCOL_DP;
>>>> break;
>>>> - }
>>>> - case PHY_TYPE_PCIE: {
>>>> - static const int types[] = {
>>>> - XPSGTR_TYPE_PCIE_0,
>>>> - XPSGTR_TYPE_PCIE_1,
>>>> - XPSGTR_TYPE_PCIE_2,
>>>> - XPSGTR_TYPE_PCIE_3,
>>>> - };
>>>> -
>>>> - phy_types = types;
>>>> - num_phy_types = ARRAY_SIZE(types);
>>>> + case PHY_TYPE_PCIE:
>>>> + num_phy_types = 4;
>>>> gtr_phy->protocol = ICM_PROTOCOL_PCIE;
>>>> break;
>>>> - }
>>>> - case PHY_TYPE_SGMII: {
>>>> - static const int types[] = {
>>>> - XPSGTR_TYPE_SGMII0,
>>>> - XPSGTR_TYPE_SGMII1,
>>>> - XPSGTR_TYPE_SGMII2,
>>>> - XPSGTR_TYPE_SGMII3,
>>>> - };
>>>> -
>>>> - phy_types = types;
>>>> - num_phy_types = ARRAY_SIZE(types);
>>>> + case PHY_TYPE_SGMII:
>>>> + num_phy_types = 4;
>>>> gtr_phy->protocol = ICM_PROTOCOL_SGMII;
>>>> break;
>>>> - }
>>>> default:
>>>> return -EINVAL;
>>>> }
>>>> @@ -748,7 +692,7 @@ static int xpsgtr_set_lane_type(struct xpsgtr_phy *gtr_phy, u8 phy_type,
>>>> if (phy_instance >= num_phy_types)
>>>> return -EINVAL;
>>>> - gtr_phy->type = phy_types[phy_instance];
>>>> + gtr_phy->instance = phy_instance;
>>>> return 0;
>>>> }
>>>> @@ -756,14 +700,11 @@ static int xpsgtr_set_lane_type(struct xpsgtr_phy *gtr_phy, u8 phy_type,
>>>> * Valid combinations of controllers and lanes (Interconnect Matrix).
>>>> */
>>>> static const unsigned int icm_matrix[NUM_LANES][CONTROLLERS_PER_LANE] = {
>>>> - { XPSGTR_TYPE_PCIE_0, XPSGTR_TYPE_SATA_0, XPSGTR_TYPE_USB0,
>>>> - XPSGTR_TYPE_DP_1, XPSGTR_TYPE_SGMII0 },
>>>> - { XPSGTR_TYPE_PCIE_1, XPSGTR_TYPE_SATA_1, XPSGTR_TYPE_USB0,
>>>> - XPSGTR_TYPE_DP_0, XPSGTR_TYPE_SGMII1 },
>>>> - { XPSGTR_TYPE_PCIE_2, XPSGTR_TYPE_SATA_0, XPSGTR_TYPE_USB0,
>>>> - XPSGTR_TYPE_DP_1, XPSGTR_TYPE_SGMII2 },
>>>> - { XPSGTR_TYPE_PCIE_3, XPSGTR_TYPE_SATA_1, XPSGTR_TYPE_USB1,
>>>> - XPSGTR_TYPE_DP_0, XPSGTR_TYPE_SGMII3 }
>>>> + /* PCIe, SATA, USB, DP, SGMII */
>>>> + { 0, 0, 0, 1, 0 },
>>>> + { 1, 1, 0, 0, 1 },
>>>> + { 2, 0, 0, 1, 2 },
>>>> + { 3, 1, 1, 0, 3 },
>>>
>>>
>>> Do you think that this is more understandable than was before?
>>
>> Yes. This better matches the documentation. And now it is easier to
>> programmatically access the index. Before we might have
>>
>> protocol = ICM_PROTOCOL_USB
>> type = XPSGTR_TYPE_USB0
>>
>> and the instance is there in the type name, but we can't access it. Now
>> we have
>>
>> instance = 0
>>
>> and it is easy to determine which instance we have.
>
> Numbers itself means in PCIE, SATA and DP number of lanes used but
> there is only single controller. In USB and SGMII case it is one lane
> per controller which is different information pointing to controller
> ID.

Yeah, the instance is really just to validate the devicetree binding.
It's not used in the driver except to determine the lane to wait for PLL
lock on in a multi-lane configuration.

> I didn't look at this driver for a while but at least for this array I
> would prefer to extend comment above to describe position of
> controllers and connected lanes and explain what that numbers really
> means.

OK, I will expand the comment for v2.

--Sean