[PATCH v6 04/11] power: sequencing: pcie-m2: Report power controllability

[Loic Poulain]

The M.2 Key E connector gates/resets its functions through the
W_DISABLE1# (PCIe/WiFi) and W_DISABLE2# (Bluetooth) signals.
When a signal is not routed to a host GPIO, the corresponding
enable/disable callbacks are no-ops, so the consumer cannot gate
or reset that function on its own.

Implement the .is_controllable() callback on the "uart" and "pcie"
targets so that consumers can query this per instance (based on the
runtime presence of the W_DISABLE2#/W_DISABLE1# GPIOs) via
pwrseq_is_controllable().

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxxxxxxxx>
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxxxxxxxx>
---
 drivers/power/sequencing/pwrseq-pcie-m2.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/power/sequencing/pwrseq-pcie-m2.c b/drivers/power/sequencing/pwrseq-pcie-m2.c
index de9848a9a9f19dba6d2e9d756c3d30f6648738ed..bee1aa0e077db139a52d307890053492b4513db2 100644
--- a/drivers/power/sequencing/pwrseq-pcie-m2.c
+++ b/drivers/power/sequencing/pwrseq-pcie-m2.c
@@ -83,6 +83,18 @@ static int pwrseq_pci_m2_e_uart_disable(struct pwrseq_device *pwrseq)
 	return gpiod_set_value_cansleep(ctx->w_disable2_gpio, 1);
 }
 
+static bool pwrseq_pci_m2_e_uart_is_controllable(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_pcie_m2_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	/*
+	 * The UART enable is driven through the W_DISABLE2# line. When it is not
+	 * wired up on this connector the enable/disable callbacks are no-ops, so
+	 * the host cannot gate the Bluetooth function on its own.
+	 */
+	return !!ctx->w_disable2_gpio;
+}
+
 static const struct pwrseq_unit_data pwrseq_pcie_m2_e_uart_unit_data = {
 	.name = "uart-enable",
 	.deps = pwrseq_pcie_m2_unit_deps,
@@ -104,6 +116,18 @@ static int pwrseq_pci_m2_e_pcie_disable(struct pwrseq_device *pwrseq)
 	return gpiod_set_value_cansleep(ctx->w_disable1_gpio, 1);
 }
 
+static bool pwrseq_pci_m2_e_pcie_is_controllable(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_pcie_m2_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	/*
+	 * The PCIe/WiFi enable is driven through the W_DISABLE1# line. When it
+	 * is not wired up on this connector the enable/disable callbacks are
+	 * no-ops, so the host cannot gate the PCIe/WiFi function on its own.
+	 */
+	return !!ctx->w_disable1_gpio;
+}
+
 static const struct pwrseq_unit_data pwrseq_pcie_m2_e_pcie_unit_data = {
 	.name = "pcie-enable",
 	.deps = pwrseq_pcie_m2_unit_deps,
@@ -132,12 +156,14 @@ static const struct pwrseq_target_data pwrseq_pcie_m2_e_uart_target_data = {
 	.name = "uart",
 	.unit = &pwrseq_pcie_m2_e_uart_unit_data,
 	.post_enable = pwrseq_pcie_m2_e_pwup_delay,
+	.is_controllable = pwrseq_pci_m2_e_uart_is_controllable,
 };
 
 static const struct pwrseq_target_data pwrseq_pcie_m2_e_pcie_target_data = {
 	.name = "pcie",
 	.unit = &pwrseq_pcie_m2_e_pcie_unit_data,
 	.post_enable = pwrseq_pcie_m2_e_pwup_delay,
+	.is_controllable = pwrseq_pci_m2_e_pcie_is_controllable,
 };
 
 static const struct pwrseq_target_data pwrseq_pcie_m2_m_pcie_target_data = {

-- 
2.34.1