firmware: ti_sci: Add support for Clock control

Texas Instrument's System Control Interface (TI-SCI) Message Protocol
is used in Texas Instrument's System on Chip (SoC) such as those
in keystone family K2G SoC to communicate between various compute
processors with a central system controller entity.

TI-SCI message protocol provides support for management of various
hardware entities within the SoC. Add support driver to allow
communication with system controller entity within the SoC using the
mailbox client.

In general, we expect to function at a device level of abstraction,
however, for proper operation of hardware blocks, many clocks directly
supplying the hardware block needs to be queried or configured.

Introduce support for the set of SCI message protocol support that
provide us with this capability.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>

1 files changed, 289 insertions, 0 deletions

diff --git a/drivers/firmware/ti_sci.h b/drivers/firmware/ti_sci.h
index 29ce0532a7ca..f69907cfc128 100644
--- a/drivers/firmware/ti_sci.h
+++ b/drivers/firmware/ti_sci.h
@@ -52,6 +52,16 @@
 #define TI_SCI_MSG_GET_DEVICE_STATE	0x0201
 #define TI_SCI_MSG_SET_DEVICE_RESETS	0x0202
 
+/* Clock requests */
+#define TI_SCI_MSG_SET_CLOCK_STATE	0x0100
+#define TI_SCI_MSG_GET_CLOCK_STATE	0x0101
+#define TI_SCI_MSG_SET_CLOCK_PARENT	0x0102
+#define TI_SCI_MSG_GET_CLOCK_PARENT	0x0103
+#define TI_SCI_MSG_GET_NUM_CLOCK_PARENTS 0x0104
+#define TI_SCI_MSG_SET_CLOCK_FREQ	0x010c
+#define TI_SCI_MSG_QUERY_CLOCK_FREQ	0x010d
+#define TI_SCI_MSG_GET_CLOCK_FREQ	0x010e
+
 /**
  * struct ti_sci_msg_hdr - Generic Message Header for All messages and responses
  * @type:	Type of messages: One of TI_SCI_MSG* values
@@ -188,4 +198,283 @@ struct ti_sci_msg_req_set_device_resets {
 	u32 resets;
 } __packed;
 
+/**
+ * struct ti_sci_msg_req_set_clock_state - Request to setup a Clock state
+ * @hdr:	Generic Header, Certain flags can be set specific to the clocks:
+ *		MSG_FLAG_CLOCK_ALLOW_SSC: Allow this clock to be modified
+ *		via spread spectrum clocking.
+ *		MSG_FLAG_CLOCK_ALLOW_FREQ_CHANGE: Allow this clock's
+ *		frequency to be changed while it is running so long as it
+ *		is within the min/max limits.
+ *		MSG_FLAG_CLOCK_INPUT_TERM: Enable input termination, this
+ *		is only applicable to clock inputs on the SoC pseudo-device.
+ * @dev_id:	Device identifier this request is for
+ * @clk_id:	Clock identifier for the device for this request.
+ *		Each device has it's own set of clock inputs. This indexes
+ *		which clock input to modify.
+ * @request_state: Request the state for the clock to be set to.
+ *		MSG_CLOCK_SW_STATE_UNREQ: The IP does not require this clock,
+ *		it can be disabled, regardless of the state of the device
+ *		MSG_CLOCK_SW_STATE_AUTO: Allow the System Controller to
+ *		automatically manage the state of this clock. If the device
+ *		is enabled, then the clock is enabled. If the device is set
+ *		to off or retention, then the clock is internally set as not
+ *		being required by the device.(default)
+ *		MSG_CLOCK_SW_STATE_REQ:  Configure the clock to be enabled,
+ *		regardless of the state of the device.
+ *
+ * Normally, all required clocks are managed by TISCI entity, this is used
+ * only for specific control *IF* required. Auto managed state is
+ * MSG_CLOCK_SW_STATE_AUTO, in other states, TISCI entity assume remote
+ * will explicitly control.
+ *
+ * Request type is TI_SCI_MSG_SET_CLOCK_STATE, response is a generic
+ * ACK or NACK message.
+ */
+struct ti_sci_msg_req_set_clock_state {
+	/* Additional hdr->flags options */
+#define MSG_FLAG_CLOCK_ALLOW_SSC		TI_SCI_MSG_FLAG(8)
+#define MSG_FLAG_CLOCK_ALLOW_FREQ_CHANGE	TI_SCI_MSG_FLAG(9)
+#define MSG_FLAG_CLOCK_INPUT_TERM		TI_SCI_MSG_FLAG(10)
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u8 clk_id;
+#define MSG_CLOCK_SW_STATE_UNREQ	0
+#define MSG_CLOCK_SW_STATE_AUTO		1
+#define MSG_CLOCK_SW_STATE_REQ		2
+	u8 request_state;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_get_clock_state - Request for clock state
+ * @hdr:	Generic Header
+ * @dev_id:	Device identifier this request is for
+ * @clk_id:	Clock identifier for the device for this request.
+ *		Each device has it's own set of clock inputs. This indexes
+ *		which clock input to get state of.
+ *
+ * Request type is TI_SCI_MSG_GET_CLOCK_STATE, response is state
+ * of the clock
+ */
+struct ti_sci_msg_req_get_clock_state {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u8 clk_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_get_clock_state - Response to get clock state
+ * @hdr:	Generic Header
+ * @programmed_state: Any programmed state of the clock. This is one of
+ *		MSG_CLOCK_SW_STATE* values.
+ * @current_state: Current state of the clock. This is one of:
+ *		MSG_CLOCK_HW_STATE_NOT_READY: Clock is not ready
+ *		MSG_CLOCK_HW_STATE_READY: Clock is ready
+ *
+ * Response to TI_SCI_MSG_GET_CLOCK_STATE.
+ */
+struct ti_sci_msg_resp_get_clock_state {
+	struct ti_sci_msg_hdr hdr;
+	u8 programmed_state;
+#define MSG_CLOCK_HW_STATE_NOT_READY	0
+#define MSG_CLOCK_HW_STATE_READY	1
+	u8 current_state;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_set_clock_parent - Set the clock parent
+ * @hdr:	Generic Header
+ * @dev_id:	Device identifier this request is for
+ * @clk_id:	Clock identifier for the device for this request.
+ *		Each device has it's own set of clock inputs. This indexes
+ *		which clock input to modify.
+ * @parent_id:	The new clock parent is selectable by an index via this
+ *		parameter.
+ *
+ * Request type is TI_SCI_MSG_SET_CLOCK_PARENT, response is generic
+ * ACK / NACK message.
+ */
+struct ti_sci_msg_req_set_clock_parent {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u8 clk_id;
+	u8 parent_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_get_clock_parent - Get the clock parent
+ * @hdr:	Generic Header
+ * @dev_id:	Device identifier this request is for
+ * @clk_id:	Clock identifier for the device for this request.
+ *		Each device has it's own set of clock inputs. This indexes
+ *		which clock input to get the parent for.
+ *
+ * Request type is TI_SCI_MSG_GET_CLOCK_PARENT, response is parent information
+ */
+struct ti_sci_msg_req_get_clock_parent {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u8 clk_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_get_clock_parent - Response with clock parent
+ * @hdr:	Generic Header
+ * @parent_id:	The current clock parent
+ *
+ * Response to TI_SCI_MSG_GET_CLOCK_PARENT.
+ */
+struct ti_sci_msg_resp_get_clock_parent {
+	struct ti_sci_msg_hdr hdr;
+	u8 parent_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_get_clock_num_parents - Request to get clock parents
+ * @hdr:	Generic header
+ * @dev_id:	Device identifier this request is for
+ * @clk_id:	Clock identifier for the device for this request.
+ *
+ * This request provides information about how many clock parent options
+ * are available for a given clock to a device. This is typically used
+ * for input clocks.
+ *
+ * Request type is TI_SCI_MSG_GET_NUM_CLOCK_PARENTS, response is appropriate
+ * message, or NACK in case of inability to satisfy request.
+ */
+struct ti_sci_msg_req_get_clock_num_parents {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u8 clk_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_get_clock_num_parents - Response for get clk parents
+ * @hdr:		Generic header
+ * @num_parents:	Number of clock parents
+ *
+ * Response to TI_SCI_MSG_GET_NUM_CLOCK_PARENTS
+ */
+struct ti_sci_msg_resp_get_clock_num_parents {
+	struct ti_sci_msg_hdr hdr;
+	u8 num_parents;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_query_clock_freq - Request to query a frequency
+ * @hdr:	Generic Header
+ * @dev_id:	Device identifier this request is for
+ * @min_freq_hz: The minimum allowable frequency in Hz. This is the minimum
+ *		allowable programmed frequency and does not account for clock
+ *		tolerances and jitter.
+ * @target_freq_hz: The target clock frequency. A frequency will be found
+ *		as close to this target frequency as possible.
+ * @max_freq_hz: The maximum allowable frequency in Hz. This is the maximum
+ *		allowable programmed frequency and does not account for clock
+ *		tolerances and jitter.
+ * @clk_id:	Clock identifier for the device for this request.
+ *
+ * NOTE: Normally clock frequency management is automatically done by TISCI
+ * entity. In case of specific requests, TISCI evaluates capability to achieve
+ * requested frequency within provided range and responds with
+ * result message.
+ *
+ * Request type is TI_SCI_MSG_QUERY_CLOCK_FREQ, response is appropriate message,
+ * or NACK in case of inability to satisfy request.
+ */
+struct ti_sci_msg_req_query_clock_freq {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u64 min_freq_hz;
+	u64 target_freq_hz;
+	u64 max_freq_hz;
+	u8 clk_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_query_clock_freq - Response to a clock frequency query
+ * @hdr:	Generic Header
+ * @freq_hz:	Frequency that is the best match in Hz.
+ *
+ * Response to request type TI_SCI_MSG_QUERY_CLOCK_FREQ. NOTE: if the request
+ * cannot be satisfied, the message will be of type NACK.
+ */
+struct ti_sci_msg_resp_query_clock_freq {
+	struct ti_sci_msg_hdr hdr;
+	u64 freq_hz;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_set_clock_freq - Request to setup a clock frequency
+ * @hdr:	Generic Header
+ * @dev_id:	Device identifier this request is for
+ * @min_freq_hz: The minimum allowable frequency in Hz. This is the minimum
+ *		allowable programmed frequency and does not account for clock
+ *		tolerances and jitter.
+ * @target_freq_hz: The target clock frequency. The clock will be programmed
+ *		at a rate as close to this target frequency as possible.
+ * @max_freq_hz: The maximum allowable frequency in Hz. This is the maximum
+ *		allowable programmed frequency and does not account for clock
+ *		tolerances and jitter.
+ * @clk_id:	Clock identifier for the device for this request.
+ *
+ * NOTE: Normally clock frequency management is automatically done by TISCI
+ * entity. In case of specific requests, TISCI evaluates capability to achieve
+ * requested range and responds with success/failure message.
+ *
+ * This sets the desired frequency for a clock within an allowable
+ * range. This message will fail on an enabled clock unless
+ * MSG_FLAG_CLOCK_ALLOW_FREQ_CHANGE is set for the clock. Additionally,
+ * if other clocks have their frequency modified due to this message,
+ * they also must have the MSG_FLAG_CLOCK_ALLOW_FREQ_CHANGE or be disabled.
+ *
+ * Calling set frequency on a clock input to the SoC pseudo-device will
+ * inform the PMMC of that clock's frequency. Setting a frequency of
+ * zero will indicate the clock is disabled.
+ *
+ * Calling set frequency on clock outputs from the SoC pseudo-device will
+ * function similarly to setting the clock frequency on a device.
+ *
+ * Request type is TI_SCI_MSG_SET_CLOCK_FREQ, response is a generic ACK/NACK
+ * message.
+ */
+struct ti_sci_msg_req_set_clock_freq {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u64 min_freq_hz;
+	u64 target_freq_hz;
+	u64 max_freq_hz;
+	u8 clk_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_req_get_clock_freq - Request to get the clock frequency
+ * @hdr:	Generic Header
+ * @dev_id:	Device identifier this request is for
+ * @clk_id:	Clock identifier for the device for this request.
+ *
+ * NOTE: Normally clock frequency management is automatically done by TISCI
+ * entity. In some cases, clock frequencies are configured by host.
+ *
+ * Request type is TI_SCI_MSG_GET_CLOCK_FREQ, responded with clock frequency
+ * that the clock is currently at.
+ */
+struct ti_sci_msg_req_get_clock_freq {
+	struct ti_sci_msg_hdr hdr;
+	u32 dev_id;
+	u8 clk_id;
+} __packed;
+
+/**
+ * struct ti_sci_msg_resp_get_clock_freq - Response of clock frequency request
+ * @hdr:	Generic Header
+ * @freq_hz:	Frequency that the clock is currently on, in Hz.
+ *
+ * Response to request type TI_SCI_MSG_GET_CLOCK_FREQ.
+ */
+struct ti_sci_msg_resp_get_clock_freq {
+	struct ti_sci_msg_hdr hdr;
+	u64 freq_hz;
+} __packed;
+
 #endif /* __TI_SCI_H */