[PATCH v2] clk: qcom: rpmcc: Add support to XO buffered clocks

From: srinivas . kandagatla
Date: Sun Mar 18 2018 - 10:46:22 EST


From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>

XO is onchip buffer clock to generate 19.2MHz.

This patch adds support to 5 XO buffer clocks found on PMIC8921,
these buffer clocks can be controlled from external pin or in
manual mode.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
Changes since v1:
- Made buffer clk word global and protected it by mutex, suggested by S Boyd.
- removed rate from clock define as it can be derived from parent clk rate,
suggested by S Boyd.

drivers/clk/qcom/clk-rpm.c | 79 +++++++++++++++++++++++++++++++++-
include/dt-bindings/clock/qcom,rpmcc.h | 5 +++
2 files changed, 83 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-rpm.c b/drivers/clk/qcom/clk-rpm.c
index c60f61b10c7f..b94981447664 100644
--- a/drivers/clk/qcom/clk-rpm.c
+++ b/drivers/clk/qcom/clk-rpm.c
@@ -29,6 +29,7 @@

#define QCOM_RPM_MISC_CLK_TYPE 0x306b6c63
#define QCOM_RPM_SCALING_ENABLE_ID 0x2
+#define QCOM_RPM_XO_MODE_ON 0x2

#define DEFINE_CLK_RPM(_platform, _name, _active, r_id) \
static struct clk_rpm _platform##_##_active; \
@@ -56,6 +57,18 @@
}, \
}

+#define DEFINE_CLK_RPM_XO_BUFFER(_platform, _name, _active, offset) \
+ static struct clk_rpm _platform##_##_name = { \
+ .rpm_clk_id = QCOM_RPM_CXO_BUFFERS, \
+ .xo_offset = (offset), \
+ .hw.init = &(struct clk_init_data){ \
+ .ops = &clk_rpm_xo_ops, \
+ .name = #_name, \
+ .parent_names = (const char *[]){ "cxo_board" }, \
+ .num_parents = 1, \
+ }, \
+ }
+
#define DEFINE_CLK_RPM_FIXED(_platform, _name, _active, r_id, r) \
static struct clk_rpm _platform##_##_name = { \
.rpm_clk_id = (r_id), \
@@ -126,8 +139,11 @@

#define to_clk_rpm(_hw) container_of(_hw, struct clk_rpm, hw)

+struct rpm_cc;
+
struct clk_rpm {
const int rpm_clk_id;
+ const int xo_offset;
const bool active_only;
unsigned long rate;
bool enabled;
@@ -135,12 +151,15 @@ struct clk_rpm {
struct clk_rpm *peer;
struct clk_hw hw;
struct qcom_rpm *rpm;
+ struct rpm_cc *rpm_cc;
};

struct rpm_cc {
struct qcom_rpm *rpm;
struct clk_rpm **clks;
size_t num_clks;
+ u32 xo_buffer_value;
+ struct mutex xo_lock;
};

struct rpm_clk_desc {
@@ -159,7 +178,8 @@ static int clk_rpm_handoff(struct clk_rpm *r)
* The vendor tree simply reads the status for this
* RPM clock.
*/
- if (r->rpm_clk_id == QCOM_RPM_PLL_4)
+ if (r->rpm_clk_id == QCOM_RPM_PLL_4 ||
+ r->rpm_clk_id == QCOM_RPM_CXO_BUFFERS)
return 0;

ret = qcom_rpm_write(r->rpm, QCOM_RPM_ACTIVE_STATE,
@@ -288,6 +308,46 @@ static void clk_rpm_unprepare(struct clk_hw *hw)
mutex_unlock(&rpm_clk_lock);
}

+static int clk_rpm_xo_prepare(struct clk_hw *hw)
+{
+ struct clk_rpm *r = to_clk_rpm(hw);
+ struct rpm_cc *rcc = r->rpm_cc;
+ int ret, clk_id = r->rpm_clk_id;
+ u32 value;
+
+ mutex_lock(&rcc->xo_lock);
+
+ value = rcc->xo_buffer_value | (QCOM_RPM_XO_MODE_ON << r->xo_offset);
+ ret = qcom_rpm_write(r->rpm, QCOM_RPM_ACTIVE_STATE, clk_id, &value, 1);
+ if (!ret) {
+ r->enabled = true;
+ rcc->xo_buffer_value = value;
+ }
+
+ mutex_unlock(&rcc->xo_lock);
+
+ return ret;
+}
+
+static void clk_rpm_xo_unprepare(struct clk_hw *hw)
+{
+ struct clk_rpm *r = to_clk_rpm(hw);
+ struct rpm_cc *rcc = r->rpm_cc;
+ int ret, clk_id = r->rpm_clk_id;
+ u32 value;
+
+ mutex_lock(&rcc->xo_lock);
+
+ value = rcc->xo_buffer_value & ~(QCOM_RPM_XO_MODE_ON << r->xo_offset);
+ ret = qcom_rpm_write(r->rpm, QCOM_RPM_ACTIVE_STATE, clk_id, &value, 1);
+ if (!ret) {
+ r->enabled = false;
+ rcc->xo_buffer_value = value;
+ }
+
+ mutex_unlock(&rcc->xo_lock);
+}
+
static int clk_rpm_fixed_prepare(struct clk_hw *hw)
{
struct clk_rpm *r = to_clk_rpm(hw);
@@ -378,6 +438,11 @@ static unsigned long clk_rpm_recalc_rate(struct clk_hw *hw,
return r->rate;
}

+static const struct clk_ops clk_rpm_xo_ops = {
+ .prepare = clk_rpm_xo_prepare,
+ .unprepare = clk_rpm_xo_unprepare,
+};
+
static const struct clk_ops clk_rpm_fixed_ops = {
.prepare = clk_rpm_fixed_prepare,
.unprepare = clk_rpm_fixed_unprepare,
@@ -449,6 +514,11 @@ DEFINE_CLK_RPM(apq8064, mmfpb_clk, mmfpb_a_clk, QCOM_RPM_MMFPB_CLK);
DEFINE_CLK_RPM(apq8064, sfab_clk, sfab_a_clk, QCOM_RPM_SYS_FABRIC_CLK);
DEFINE_CLK_RPM(apq8064, sfpb_clk, sfpb_a_clk, QCOM_RPM_SFPB_CLK);
DEFINE_CLK_RPM(apq8064, qdss_clk, qdss_a_clk, QCOM_RPM_QDSS_CLK);
+DEFINE_CLK_RPM_XO_BUFFER(apq8064, xo_d0_clk, xo_d0_a_clk, 0);
+DEFINE_CLK_RPM_XO_BUFFER(apq8064, xo_d1_clk, xo_d1_a_clk, 8);
+DEFINE_CLK_RPM_XO_BUFFER(apq8064, xo_a0_clk, xo_a0_a_clk, 16);
+DEFINE_CLK_RPM_XO_BUFFER(apq8064, xo_a1_clk, xo_a1_a_clk, 24);
+DEFINE_CLK_RPM_XO_BUFFER(apq8064, xo_a2_clk, xo_a2_a_clk, 28);

static struct clk_rpm *apq8064_clks[] = {
[RPM_APPS_FABRIC_CLK] = &apq8064_afab_clk,
@@ -469,6 +539,11 @@ static struct clk_rpm *apq8064_clks[] = {
[RPM_SFPB_A_CLK] = &apq8064_sfpb_a_clk,
[RPM_QDSS_CLK] = &apq8064_qdss_clk,
[RPM_QDSS_A_CLK] = &apq8064_qdss_a_clk,
+ [RPM_XO_D0] = &apq8064_xo_d0_clk,
+ [RPM_XO_D1] = &apq8064_xo_d1_clk,
+ [RPM_XO_A0] = &apq8064_xo_a0_clk,
+ [RPM_XO_A1] = &apq8064_xo_a1_clk,
+ [RPM_XO_A2] = &apq8064_xo_a2_clk,
};

static const struct rpm_clk_desc rpm_clk_apq8064 = {
@@ -526,12 +601,14 @@ static int rpm_clk_probe(struct platform_device *pdev)

rcc->clks = rpm_clks;
rcc->num_clks = num_clks;
+ mutex_init(&rcc->xo_lock);

for (i = 0; i < num_clks; i++) {
if (!rpm_clks[i])
continue;

rpm_clks[i]->rpm = rpm;
+ rpm_clks[i]->rpm_cc = rcc;

ret = clk_rpm_handoff(rpm_clks[i]);
if (ret)
diff --git a/include/dt-bindings/clock/qcom,rpmcc.h b/include/dt-bindings/clock/qcom,rpmcc.h
index b8337a5fa347..c585b82b9c05 100644
--- a/include/dt-bindings/clock/qcom,rpmcc.h
+++ b/include/dt-bindings/clock/qcom,rpmcc.h
@@ -40,6 +40,11 @@
#define RPM_SMI_CLK 22
#define RPM_SMI_A_CLK 23
#define RPM_PLL4_CLK 24
+#define RPM_XO_D0 25
+#define RPM_XO_D1 26
+#define RPM_XO_A0 27
+#define RPM_XO_A1 28
+#define RPM_XO_A2 29

/* SMD RPM clocks */
#define RPM_SMD_XO_CLK_SRC 0
--
2.16.2