[RFC PATCH v3 5/8] firmware: Add legacy SCPI protocol driver
Neil Armstrong
narmstrong at baylibre.com
Tue Aug 16 02:41:51 PDT 2016
On 08/15/2016 03:35 PM, Sudeep Holla wrote:
> Hi Neil,
>
> On 09/08/16 11:29, Neil Armstrong wrote:
>> Add legacy protocol driver for an early published SCPI implementation
>> by supporting old command indexes and structure.
>> This driver also supports vendor messages and rockchip specific
>> mailbox data structure for message passing to SCP.
>>
>
Hi Sudeep,
> Sorry for the delay but I expected some attempts to reduce the
> duplication of code we have here. I really don't like the duplication of
> the code. As I mentioned earlier it can be reduced. I see lot of scope
> for that and I see that you made zero attempts since v2.
Yes, this post is an intermediate RFC to show to rockchip guys how I could implement support
for their vendor commands, the next RFC will certainly merge the two drivers with minimal code
duplication.
>
>> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
>> ---
>> drivers/firmware/Kconfig | 20 ++
>> drivers/firmware/Makefile | 1 +
>> drivers/firmware/legacy_scpi.c | 710 +++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 731 insertions(+)
>> create mode 100644 drivers/firmware/legacy_scpi.c
>>
>> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
>> index ff85511..f6226b7 100644
>> --- a/drivers/firmware/Kconfig
>> +++ b/drivers/firmware/Kconfig
>> @@ -40,6 +40,26 @@ config ARM_SCPI_POWER_DOMAIN
>> This enables support for the SCPI power domains which can be
>> enabled or disabled via the SCP firmware
>>
>> +config LEGACY_SCPI_PROTOCOL
>> + bool "Legacy System Control and Power Interface (SCPI) Message Protocol"
>> + default y if ARCH_MESON
>> + select SCPI_FW
>> + help
>> + System Control and Power Interface (SCPI) Message Protocol is
>> + defined for the purpose of communication between the Application
>> + Cores(AP) and the System Control Processor(SCP). The MHU peripheral
>> + provides a mechanism for inter-processor communication between SCP
>> + and AP.
>> +
>> + SCP controls most of the power managament on the Application
>> + Processors. It offers control and management of: the core/cluster
>> + power states, various power domain DVFS including the core/cluster,
>> + certain system clocks configuration, thermal sensors and many
>> + others.
>> +
>> + This protocol library provides interface for all the client drivers
>> + making use of the features offered by the legacy SCP protocol.
>> +
>
> Why do we need this ? If we plan to enable this in defconfig, I would
> rather not introduce this as it serves nothing extra over the
> compatible. We need runtime check for this with DT compatibles.
>
>
> [...]
>
>
>> +enum legacy_scpi_client_id {
>> + SCPI_CL_NONE,
>> + SCPI_CL_CLOCKS,
>> + SCPI_CL_DVFS,
>> + SCPI_CL_POWER,
>> + SCPI_CL_THERMAL,
>> + SCPI_MAX,
>> +};
>> +
>
> As I said before these values were introduced by me initially and I
> reckon firmware doesn't depend on that. Have you really tested dropping
> them ? This must go as they are useless and we now have tokens which are
> much better.
I am not sure, I'm currently waiting for Amlogic's SCPI FW specification to be sure
these are not needed at all, in the meantime I will still implement them.
>
> I will stop here and ask why can't you start with simple change like
> below ? Then we can add or re-define the structures/enums when
> absolutely needed. Please don't just copy the entire driver and make
> changes where-ever needed or please try to adapt to the new driver and
> try to deviate as less as required by the firmware.
It will be done in RFC v4.
> Regards,
> Sudeep
Thanks,
Neil
>
> --->8
>
> diff --git i/drivers/firmware/arm_scpi.c w/drivers/firmware/arm_scpi.c
> index 438893762076..b394ffb5939c 100644
> --- i/drivers/firmware/arm_scpi.c
> +++ w/drivers/firmware/arm_scpi.c
> @@ -82,6 +82,9 @@
>
> #define MAX_RX_TIMEOUT (msecs_to_jiffies(30))
>
> +typedef int (*scpi_send_msg_func)(u8 cmd, void *tx_buf, unsigned int tx_len,
> + void *rx_buf, unsigned int rx_len);
> +
> enum scpi_error_codes {
> SCPI_SUCCESS = 0, /* Success */
> SCPI_ERR_PARAM = 1, /* Invalid parameter(s) */
> @@ -162,6 +165,7 @@ struct scpi_drvinfo {
> u32 firmware_version;
> int num_chans;
> atomic_t next_chan;
> + scpi_send_msg_func send_msg;
> struct scpi_ops *scpi_ops;
> struct scpi_chan *channels;
> struct scpi_dvfs_info *dvfs[MAX_DVFS_DOMAINS];
> @@ -397,8 +401,8 @@ scpi_clk_get_range(u16 clk_id, unsigned long *min, unsigned long *max)
> struct clk_get_info clk;
> __le16 le_clk_id = cpu_to_le16(clk_id);
>
> - ret = scpi_send_message(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
> - sizeof(le_clk_id), &clk, sizeof(clk));
> + ret = scpi_info->send_msg(SCPI_CMD_GET_CLOCK_INFO, &le_clk_id,
> + sizeof(le_clk_id), &clk, sizeof(clk));
> if (!ret) {
> *min = le32_to_cpu(clk.min_rate);
> *max = le32_to_cpu(clk.max_rate);
> @@ -412,8 +416,8 @@ static unsigned long scpi_clk_get_val(u16 clk_id)
> struct clk_get_value clk;
> __le16 le_clk_id = cpu_to_le16(clk_id);
>
> - ret = scpi_send_message(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
> - sizeof(le_clk_id), &clk, sizeof(clk));
> + ret = scpi_info->send_msg(SCPI_CMD_GET_CLOCK_VALUE, &le_clk_id,
> + sizeof(le_clk_id), &clk, sizeof(clk));
> return ret ? ret : le32_to_cpu(clk.rate);
> }
>
> @@ -425,8 +429,8 @@ static int scpi_clk_set_val(u16 clk_id, unsigned long rate)
> .rate = cpu_to_le32(rate)
> };
>
> - return scpi_send_message(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
> - &stat, sizeof(stat));
> + return scpi_info->send_msg(SCPI_CMD_SET_CLOCK_VALUE, &clk, sizeof(clk),
> + &stat, sizeof(stat));
> }
>
> static int scpi_dvfs_get_idx(u8 domain)
> @@ -434,8 +438,8 @@ static int scpi_dvfs_get_idx(u8 domain)
> int ret;
> u8 dvfs_idx;
>
> - ret = scpi_send_message(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
> - &dvfs_idx, sizeof(dvfs_idx));
> + ret = scpi_info->send_msg(SCPI_CMD_GET_DVFS, &domain, sizeof(domain),
> + &dvfs_idx, sizeof(dvfs_idx));
> return ret ? ret : dvfs_idx;
> }
>
> @@ -444,8 +448,8 @@ static int scpi_dvfs_set_idx(u8 domain, u8 index)
> int stat;
> struct dvfs_set dvfs = {domain, index};
>
> - return scpi_send_message(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
> - &stat, sizeof(stat));
> + return scpi_info->send_msg(SCPI_CMD_SET_DVFS, &dvfs, sizeof(dvfs),
> + &stat, sizeof(stat));
> }
>
> static int opp_cmp_func(const void *opp1, const void *opp2)
> @@ -468,8 +472,8 @@ static struct scpi_dvfs_info *scpi_dvfs_get_info(u8 domain)
> if (scpi_info->dvfs[domain]) /* data already populated */
> return scpi_info->dvfs[domain];
>
> - ret = scpi_send_message(SCPI_CMD_GET_DVFS_INFO, &domain, sizeof(domain),
> - &buf, sizeof(buf));
> + ret = scpi_info->send_msg(SCPI_CMD_GET_DVFS_INFO, &domain,
> + sizeof(domain), &buf, sizeof(buf));
>
> if (ret)
> return ERR_PTR(ret);
> @@ -503,8 +507,8 @@ static int scpi_sensor_get_capability(u16 *sensors)
> struct sensor_capabilities cap_buf;
> int ret;
>
> - ret = scpi_send_message(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0, &cap_buf,
> - sizeof(cap_buf));
> + ret = scpi_info->send_msg(SCPI_CMD_SENSOR_CAPABILITIES, NULL, 0,
> + &cap_buf, sizeof(cap_buf));
> if (!ret)
> *sensors = le16_to_cpu(cap_buf.sensors);
>
> @@ -517,8 +521,8 @@ static int scpi_sensor_get_info(u16 sensor_id, struct scpi_sensor_info *info)
> struct _scpi_sensor_info _info;
> int ret;
>
> - ret = scpi_send_message(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
> - &_info, sizeof(_info));
> + ret = scpi_info->send_msg(SCPI_CMD_SENSOR_INFO, &id, sizeof(id),
> + &_info, sizeof(_info));
> if (!ret) {
> memcpy(info, &_info, sizeof(*info));
> info->sensor_id = le16_to_cpu(_info.sensor_id);
> @@ -533,8 +537,8 @@ static int scpi_sensor_get_value(u16 sensor, u64 *val)
> struct sensor_value buf;
> int ret;
>
> - ret = scpi_send_message(SCPI_CMD_SENSOR_VALUE, &id, sizeof(id),
> - &buf, sizeof(buf));
> + ret = scpi_info->send_msg(SCPI_CMD_SENSOR_VALUE, &id, sizeof(id),
> + &buf, sizeof(buf));
> if (!ret)
> *val = (u64)le32_to_cpu(buf.hi_val) << 32 |
> le32_to_cpu(buf.lo_val);
> @@ -548,8 +552,8 @@ static int scpi_device_get_power_state(u16 dev_id)
> u8 pstate;
> __le16 id = cpu_to_le16(dev_id);
>
> - ret = scpi_send_message(SCPI_CMD_GET_DEVICE_PWR_STATE, &id,
> - sizeof(id), &pstate, sizeof(pstate));
> + ret = scpi_info->send_msg(SCPI_CMD_GET_DEVICE_PWR_STATE, &id,
> + sizeof(id), &pstate, sizeof(pstate));
> return ret ? ret : pstate;
> }
>
> @@ -561,8 +565,8 @@ static int scpi_device_set_power_state(u16 dev_id, u8 pstate)
> .pstate = pstate,
> };
>
> - return scpi_send_message(SCPI_CMD_SET_DEVICE_PWR_STATE, &dev_set,
> - sizeof(dev_set), &stat, sizeof(stat));
> + return scpi_info->send_msg(SCPI_CMD_SET_DEVICE_PWR_STATE, &dev_set,
> + sizeof(dev_set), &stat, sizeof(stat));
> }
>
> static struct scpi_ops scpi_ops = {
> @@ -591,8 +595,8 @@ static int scpi_init_versions(struct scpi_drvinfo *info)
> int ret;
> struct scp_capabilities caps;
>
> - ret = scpi_send_message(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
> - &caps, sizeof(caps));
> + ret = scpi_info->send_msg(SCPI_CMD_SCPI_CAPABILITIES, NULL, 0,
> + &caps, sizeof(caps));
> if (!ret) {
> info->protocol_version = le32_to_cpu(caps.protocol_version);
> info->firmware_version = le32_to_cpu(caps.platform_version);
> @@ -681,6 +685,14 @@ static int scpi_alloc_xfer_list(struct device *dev, struct scpi_chan *ch)
> return 0;
> }
>
> +static const struct of_device_id scpi_of_match[] = {
> + {.compatible = "arm,scpi", .data = scpi_send_message},
> + {.compatible = "arm,scpi-legacy", .data = scpi_send_message},
> + {},
> +};
> +
> +MODULE_DEVICE_TABLE(of, scpi_of_match);
> +
> static int scpi_probe(struct platform_device *pdev)
> {
> int count, idx, ret;
> @@ -688,11 +700,15 @@ static int scpi_probe(struct platform_device *pdev)
> struct scpi_chan *scpi_chan;
> struct device *dev = &pdev->dev;
> struct device_node *np = dev->of_node;
> + const struct of_device_id *match;
>
> scpi_info = devm_kzalloc(dev, sizeof(*scpi_info), GFP_KERNEL);
> if (!scpi_info)
> return -ENOMEM;
>
> + match = of_match_device(scpi_of_match, dev);
> + scpi_info->send_msg = match->data;
> +
> count = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
> if (count < 0) {
> dev_err(dev, "no mboxes property in '%s'\n", np->full_name);
> @@ -778,13 +794,6 @@ static int scpi_probe(struct platform_device *pdev)
> return of_platform_populate(dev->of_node, NULL, NULL, dev);
> }
>
> -static const struct of_device_id scpi_of_match[] = {
> - {.compatible = "arm,scpi"},
> - {},
> -};
> -
> -MODULE_DEVICE_TABLE(of, scpi_of_match);
> -
> static struct platform_driver scpi_driver = {
> .driver = {
> .name = "scpi_protocol",
More information about the linux-arm-kernel
mailing list