clk: qcom: clk-rpmh: Add IPA clock support

The clk-rpmh driver only supports on and off RPMh clock resources. Let's
extend the driver by adding 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 set 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 <daidavid1@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

2 files changed, 147 insertions, 0 deletions

diff --git a/drivers/clk/qcom/clk-rpmh.c b/drivers/clk/qcom/clk-rpmh.c
index 9f4fc7773fb2..c3fd632af119 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) |                  \
+        ((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
+ * @unit:               divisor to convert rate to rpmh msg in magnitudes of Khz
  * @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 @@ static DEFINE_MUTEX(rpmh_clk_lock);
         __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 +248,96 @@ static const struct clk_ops clk_rpmh_ops = {
         .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 = 0;
+        if (enable) {
+                cmd_state = 1;
+                if (c->aggr_state)
+                        cmd_state = c->aggr_state;
+        }
+
+        if (c->last_sent_aggr_state == cmd_state) {
+                mutex_unlock(&rpmh_clk_lock);
+                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);
+                mutex_unlock(&rpmh_clk_lock);
+                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);
+
+        return clk_rpmh_bcm_send_cmd(c, true);
+};
+
+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 +345,7 @@ DEFINE_CLK_RPMH_VRM(sdm845, ln_bb_clk3, ln_bb_clk3_ao, "lnbclka3", 2);
 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 +360,7 @@ static struct clk_hw *sdm845_rpmh_clocks[] = {
         [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 +397,8 @@ 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;