mfd: qcom_rpm: Fix offset error for msm8660

The RPM in MSM8660/APQ8060 has different offsets to the selector
ACK and request context ACK registers. Make all these register
offsets part of the per-SoC data and assign the right values.

The bug was found by verifying backwards to the vendor tree in
the out-of-tree files <mach/rpm-[8660|8064|8960]>: all were using
offsets 3,11,15,23 and a select size of 4, except the MSM8660/APQ8060
which was using offsets 3,11,19,27 and a select size of 7.

All other platforms apart from msm8660 were affected by reading
excess registers, since 7 was hardcoded as the number of select
words, this patch makes also this part dynamic so we only write/read
as many select words as the platform actually use.

Symptoms of this bug when using msm8660: the first RPM transaction
would work, but the next would stall or raise an error since the
previous transaction was not properly ACKed as the ACK words were
read at the wrong offset.

Cc: stable@vger.kernel.org
Fixes: 58e21438 ("mfd: qcom-rpm: Driver for the Qualcomm RPM")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Björn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/qcom_rpm.c

@@ -34,7 +34,12 @@ struct qcom_rpm_resource {
 struct qcom_rpm_data {
 	u32 version;
 	const struct qcom_rpm_resource *resource_table;
-	unsigned n_resources;
+	unsigned int n_resources;
+	unsigned int req_ctx_off;
+	unsigned int req_sel_off;
+	unsigned int ack_ctx_off;
+	unsigned int ack_sel_off;
+	unsigned int sel_size;
 };
 
 struct qcom_rpm {
@@ -61,11 +66,7 @@ struct qcom_rpm {
 
 #define RPM_REQUEST_TIMEOUT	(5 * HZ)
 
-#define RPM_REQUEST_CONTEXT	3
-#define RPM_REQ_SELECT		11
-#define RPM_ACK_CONTEXT		15
-#define RPM_ACK_SELECTOR	23
-#define RPM_SELECT_SIZE		7
+#define RPM_MAX_SEL_SIZE	7
 
 #define RPM_NOTIFICATION	BIT(30)
 #define RPM_REJECTED		BIT(31)
@@ -157,6 +158,11 @@ static const struct qcom_rpm_data apq8064_template = {
 	.version = 3,
 	.resource_table = apq8064_rpm_resource_table,
 	.n_resources = ARRAY_SIZE(apq8064_rpm_resource_table),
+	.req_ctx_off = 3,
+	.req_sel_off = 11,
+	.ack_ctx_off = 15,
+	.ack_sel_off = 23,
+	.sel_size = 4,
 };
 
 static const struct qcom_rpm_resource msm8660_rpm_resource_table[] = {
@@ -240,6 +246,11 @@ static const struct qcom_rpm_data msm8660_template = {
 	.version = 2,
 	.resource_table = msm8660_rpm_resource_table,
 	.n_resources = ARRAY_SIZE(msm8660_rpm_resource_table),
+	.req_ctx_off = 3,
+	.req_sel_off = 11,
+	.ack_ctx_off = 19,
+	.ack_sel_off = 27,
+	.sel_size = 7,
 };
 
 static const struct qcom_rpm_resource msm8960_rpm_resource_table[] = {
@@ -322,6 +333,11 @@ static const struct qcom_rpm_data msm8960_template = {
 	.version = 3,
 	.resource_table = msm8960_rpm_resource_table,
 	.n_resources = ARRAY_SIZE(msm8960_rpm_resource_table),
+	.req_ctx_off = 3,
+	.req_sel_off = 11,
+	.ack_ctx_off = 15,
+	.ack_sel_off = 23,
+	.sel_size = 4,
 };
 
 static const struct qcom_rpm_resource ipq806x_rpm_resource_table[] = {
@@ -362,6 +378,11 @@ static const struct qcom_rpm_data ipq806x_template = {
 	.version = 3,
 	.resource_table = ipq806x_rpm_resource_table,
 	.n_resources = ARRAY_SIZE(ipq806x_rpm_resource_table),
+	.req_ctx_off = 3,
+	.req_sel_off = 11,
+	.ack_ctx_off = 15,
+	.ack_sel_off = 23,
+	.sel_size = 4,
 };
 
 static const struct of_device_id qcom_rpm_of_match[] = {
@@ -380,7 +401,7 @@ int qcom_rpm_write(struct qcom_rpm *rpm,
 {
 	const struct qcom_rpm_resource *res;
 	const struct qcom_rpm_data *data = rpm->data;
-	u32 sel_mask[RPM_SELECT_SIZE] = { 0 };
+	u32 sel_mask[RPM_MAX_SEL_SIZE] = { 0 };
 	int left;
 	int ret = 0;
 	int i;
@@ -398,12 +419,12 @@ int qcom_rpm_write(struct qcom_rpm *rpm,
 		writel_relaxed(buf[i], RPM_REQ_REG(rpm, res->target_id + i));
 
 	bitmap_set((unsigned long *)sel_mask, res->select_id, 1);
-	for (i = 0; i < ARRAY_SIZE(sel_mask); i++) {
+	for (i = 0; i < rpm->data->sel_size; i++) {
 		writel_relaxed(sel_mask[i],
-			       RPM_CTRL_REG(rpm, RPM_REQ_SELECT + i));
+			       RPM_CTRL_REG(rpm, rpm->data->req_sel_off + i));
 	}
 
-	writel_relaxed(BIT(state), RPM_CTRL_REG(rpm, RPM_REQUEST_CONTEXT));
+	writel_relaxed(BIT(state), RPM_CTRL_REG(rpm, rpm->data->req_ctx_off));
 
 	reinit_completion(&rpm->ack);
 	regmap_write(rpm->ipc_regmap, rpm->ipc_offset, BIT(rpm->ipc_bit));
@@ -426,10 +447,11 @@ static irqreturn_t qcom_rpm_ack_interrupt(int irq, void *dev)
 	u32 ack;
 	int i;
 
-	ack = readl_relaxed(RPM_CTRL_REG(rpm, RPM_ACK_CONTEXT));
-	for (i = 0; i < RPM_SELECT_SIZE; i++)
-		writel_relaxed(0, RPM_CTRL_REG(rpm, RPM_ACK_SELECTOR + i));
-	writel(0, RPM_CTRL_REG(rpm, RPM_ACK_CONTEXT));
+	ack = readl_relaxed(RPM_CTRL_REG(rpm, rpm->data->ack_ctx_off));
+	for (i = 0; i < rpm->data->sel_size; i++)
+		writel_relaxed(0,
+			RPM_CTRL_REG(rpm, rpm->data->ack_sel_off + i));
+	writel(0, RPM_CTRL_REG(rpm, rpm->data->ack_ctx_off));
 
 	if (ack & RPM_NOTIFICATION) {
 		dev_warn(rpm->dev, "ignoring notification!\n");