The current clk-rpmh driver only supports on and off RPMh clock resources,
let's extend the current driver by add support for clocks that are managed
by a different type of RPMh resource known as Bus Clock Manager(BCM).
The BCM is a configurable shared resource aggregator that scales performance
based on a preset of frequency points. The Qualcomm IP Accelerator (IPA) clock
is an example of a resource that is managed by the BCM and this a requirement
from the IPA driver in order to scale its core clock.

Signed-off-by: David Dai <daidav...@codeaurora.org>
---
 drivers/clk/qcom/clk-rpmh.c           | 141 ++++++++++++++++++++++++++++++++++
 include/dt-bindings/clock/qcom,rpmh.h |   1 +
 2 files changed, 142 insertions(+)

diff --git a/drivers/clk/qcom/clk-rpmh.c b/drivers/clk/qcom/clk-rpmh.c
index 9f4fc77..ee78c4b 100644
--- a/drivers/clk/qcom/clk-rpmh.c
+++ b/drivers/clk/qcom/clk-rpmh.c
@@ -18,6 +18,31 @@
 #define CLK_RPMH_ARC_EN_OFFSET         0
 #define CLK_RPMH_VRM_EN_OFFSET         4
 
+#define BCM_TCS_CMD_COMMIT_MASK                0x40000000
+#define BCM_TCS_CMD_VALID_SHIFT                29
+#define BCM_TCS_CMD_VOTE_MASK          0x3fff
+#define BCM_TCS_CMD_VOTE_SHIFT         0
+
+#define BCM_TCS_CMD(valid, vote)                               \
+       (BCM_TCS_CMD_COMMIT_MASK |                              \
+       ((valid) << BCM_TCS_CMD_VALID_SHIFT) |                  \
+       ((cpu_to_le32(vote) &                                   \
+       BCM_TCS_CMD_VOTE_MASK) << BCM_TCS_CMD_VOTE_SHIFT))
+
+/**
+ * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager(BCM)
+ * @unit: divisor used to convert Hz value to an RPMh msg
+ * @width: multiplier used to convert Hz value to an RPMh msg
+ * @vcd: virtual clock domain that this bcm belongs to
+ * @reserved: reserved to pad the struct
+ */
+struct bcm_db {
+       __le32 unit;
+       __le16 width;
+       u8 vcd;
+       u8 reserved;
+};
+
 /**
  * struct clk_rpmh - individual rpmh clock data structure
  * @hw:                        handle between common and hardware-specific 
interfaces
@@ -29,6 +54,7 @@
  * @aggr_state:                rpmh clock aggregated state
  * @last_sent_aggr_state: rpmh clock last aggr state sent to RPMh
  * @valid_state_mask:  mask to determine the state of the rpmh clock
+ * @aux_data:          data specific to the bcm rpmh resource
  * @dev:               device to which it is attached
  * @peer:              pointer to the clock rpmh sibling
  */
@@ -42,6 +68,7 @@ struct clk_rpmh {
        u32 aggr_state;
        u32 last_sent_aggr_state;
        u32 valid_state_mask;
+       u32 unit;
        struct device *dev;
        struct clk_rpmh *peer;
 };
@@ -98,6 +125,17 @@ struct clk_rpmh_desc {
        __DEFINE_CLK_RPMH(_platform, _name, _name_active, _res_name,    \
                          CLK_RPMH_VRM_EN_OFFSET, 1, _div)
 
+#define DEFINE_CLK_RPMH_BCM(_platform, _name, _res_name)               \
+       static struct clk_rpmh _platform##_##_name = {                  \
+               .res_name = _res_name,                                  \
+               .valid_state_mask = BIT(RPMH_ACTIVE_ONLY_STATE),        \
+               .div = 1,                                               \
+               .hw.init = &(struct clk_init_data){                     \
+                       .ops = &clk_rpmh_bcm_ops,                       \
+                       .name = #_name,                                 \
+               },                                                      \
+       }
+
 static inline struct clk_rpmh *to_clk_rpmh(struct clk_hw *_hw)
 {
        return container_of(_hw, struct clk_rpmh, hw);
@@ -210,6 +248,91 @@ static unsigned long clk_rpmh_recalc_rate(struct clk_hw 
*hw,
        .recalc_rate    = clk_rpmh_recalc_rate,
 };
 
+static int clk_rpmh_bcm_send_cmd(struct clk_rpmh *c, bool enable)
+{
+       struct tcs_cmd cmd = { 0 };
+       u32 cmd_state;
+       int ret;
+
+       mutex_lock(&rpmh_clk_lock);
+
+       cmd_state = enable ? (c->aggr_state ? c->aggr_state : 1) : 0;
+
+       if (c->last_sent_aggr_state == cmd_state)
+               return 0;
+
+       cmd.addr = c->res_addr;
+       cmd.data = BCM_TCS_CMD(enable, cmd_state);
+
+       ret = rpmh_write_async(c->dev, RPMH_ACTIVE_ONLY_STATE, &cmd, 1);
+       if (ret) {
+               dev_err(c->dev, "set active state of %s failed: (%d)\n",
+                       c->res_name, ret);
+               return ret;
+       }
+
+       c->last_sent_aggr_state = cmd_state;
+
+       mutex_unlock(&rpmh_clk_lock);
+
+       return 0;
+}
+
+static int clk_rpmh_bcm_prepare(struct clk_hw *hw)
+{
+       struct clk_rpmh *c = to_clk_rpmh(hw);
+       int ret;
+
+       ret = clk_rpmh_bcm_send_cmd(c, true);
+
+       return ret;
+};
+
+static void clk_rpmh_bcm_unprepare(struct clk_hw *hw)
+{
+       struct clk_rpmh *c = to_clk_rpmh(hw);
+
+       clk_rpmh_bcm_send_cmd(c, false);
+};
+
+static int clk_rpmh_bcm_set_rate(struct clk_hw *hw, unsigned long rate,
+                                unsigned long parent_rate)
+{
+       struct clk_rpmh *c = to_clk_rpmh(hw);
+
+       c->aggr_state = rate / c->unit;
+       /*
+        * Since any non-zero value sent to hw would result in enabling the
+        * clock, only send the value if the clock has already been prepared.
+        */
+       if (clk_hw_is_prepared(hw))
+               clk_rpmh_bcm_send_cmd(c, true);
+
+       return 0;
+};
+
+static long clk_rpmh_round_rate(struct clk_hw *hw, unsigned long rate,
+                               unsigned long *parent_rate)
+{
+       return rate;
+}
+
+static unsigned long clk_rpmh_bcm_recalc_rate(struct clk_hw *hw,
+                                       unsigned long prate)
+{
+       struct clk_rpmh *c = to_clk_rpmh(hw);
+
+       return c->aggr_state * c->unit;
+}
+
+static const struct clk_ops clk_rpmh_bcm_ops = {
+       .prepare        = clk_rpmh_bcm_prepare,
+       .unprepare      = clk_rpmh_bcm_unprepare,
+       .set_rate       = clk_rpmh_bcm_set_rate,
+       .round_rate     = clk_rpmh_round_rate,
+       .recalc_rate    = clk_rpmh_bcm_recalc_rate,
+};
+
 /* Resource name must match resource id present in cmd-db. */
 DEFINE_CLK_RPMH_ARC(sdm845, bi_tcxo, bi_tcxo_ao, "xo.lvl", 0x3, 2);
 DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk2, ln_bb_clk2_ao, "lnbclka2", 2);
@@ -217,6 +340,7 @@ static unsigned long clk_rpmh_recalc_rate(struct clk_hw *hw,
 DEFINE_CLK_RPMH_VRM(sdm845, rf_clk1, rf_clk1_ao, "rfclka1", 1);
 DEFINE_CLK_RPMH_VRM(sdm845, rf_clk2, rf_clk2_ao, "rfclka2", 1);
 DEFINE_CLK_RPMH_VRM(sdm845, rf_clk3, rf_clk3_ao, "rfclka3", 1);
+DEFINE_CLK_RPMH_BCM(sdm845, ipa, "IP0");
 
 static struct clk_hw *sdm845_rpmh_clocks[] = {
        [RPMH_CXO_CLK]          = &sdm845_bi_tcxo.hw,
@@ -231,6 +355,7 @@ static unsigned long clk_rpmh_recalc_rate(struct clk_hw *hw,
        [RPMH_RF_CLK2_A]        = &sdm845_rf_clk2_ao.hw,
        [RPMH_RF_CLK3]          = &sdm845_rf_clk3.hw,
        [RPMH_RF_CLK3_A]        = &sdm845_rf_clk3_ao.hw,
+       [RPMH_IPA_CLK]          = &sdm845_ipa.hw,
 };
 
 static const struct clk_rpmh_desc clk_rpmh_sdm845 = {
@@ -267,6 +392,8 @@ static int clk_rpmh_probe(struct platform_device *pdev)
 
        for (i = 0; i < desc->num_clks; i++) {
                u32 res_addr;
+               size_t aux_data_len;
+               const struct bcm_db *data;
 
                rpmh_clk = to_clk_rpmh(hw_clks[i]);
                res_addr = cmd_db_read_addr(rpmh_clk->res_name);
@@ -275,6 +402,20 @@ static int clk_rpmh_probe(struct platform_device *pdev)
                                rpmh_clk->res_name);
                        return -ENODEV;
                }
+
+               data = cmd_db_read_aux_data(rpmh_clk->res_name, &aux_data_len);
+               if (IS_ERR(data)) {
+                       ret = PTR_ERR(data);
+                       dev_err(&pdev->dev,
+                               "error reading RPMh aux data for %s (%d)\n",
+                               rpmh_clk->res_name, ret);
+                               return ret;
+               }
+
+               /* Convert unit from Khz to Hz */
+               if (aux_data_len == sizeof(*data))
+                       rpmh_clk->unit = le32_to_cpu(data->unit) * 1000ULL;
+
                rpmh_clk->res_addr += res_addr;
                rpmh_clk->dev = &pdev->dev;
 
diff --git a/include/dt-bindings/clock/qcom,rpmh.h 
b/include/dt-bindings/clock/qcom,rpmh.h
index f48fbd6..edcab3f 100644
--- a/include/dt-bindings/clock/qcom,rpmh.h
+++ b/include/dt-bindings/clock/qcom,rpmh.h
@@ -18,5 +18,6 @@
 #define RPMH_RF_CLK2_A                         9
 #define RPMH_RF_CLK3                           10
 #define RPMH_RF_CLK3_A                         11
+#define RPMH_IPA_CLK                           12
 
 #endif
-- 
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