* [PATCH 1/2] dt-bindings: serial: qcom,msm-uartdm: Vote for shared resources
2023-11-28 9:43 [PATCH 0/2] serial: msm: Allow scaling power domains and interconnect Stephan Gerhold
@ 2023-11-28 9:43 ` Stephan Gerhold
2023-11-29 14:58 ` Rob Herring
2023-11-28 9:43 ` [PATCH 2/2] serial: msm: Use OPP table for DVFS support Stephan Gerhold
1 sibling, 1 reply; 4+ messages in thread
From: Stephan Gerhold @ 2023-11-28 9:43 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andy Gross, Bjorn Andersson, Konrad Dybcio, Jiri Slaby,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, linux-arm-msm,
linux-serial, devicetree, linux-kernel, Stephan Gerhold
Document power-domains, operating-points-v2 and interconnects to allow
making performance state votes for certain clock frequencies of the UART
DM controller. The interconnect path to DRAM is needed when UART DM is
used together with a DMA engine.
Voting for these shared resources is necessary to guarantee performance
with power management enabled. Otherwise these resources might run at
minimal performance state which is not sufficient for certain UART
baud rates.
Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
---
.../devicetree/bindings/serial/qcom,msm-uartdm.yaml | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.yaml b/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.yaml
index ee52bf8e8917..e0fa363ad7e2 100644
--- a/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.yaml
+++ b/Documentation/devicetree/bindings/serial/qcom,msm-uartdm.yaml
@@ -48,9 +48,17 @@ properties:
- const: tx
- const: rx
+ interconnects:
+ maxItems: 1
+
interrupts:
maxItems: 1
+ operating-points-v2: true
+
+ power-domains:
+ maxItems: 1
+
qcom,rx-crci:
$ref: /schemas/types.yaml#/definitions/uint32
description:
@@ -99,7 +107,9 @@ unevaluatedProperties: false
examples:
- |
+ #include <dt-bindings/interconnect/qcom,msm8996.h>
#include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/power/qcom-rpmpd.h>
serial@f991e000 {
compatible = "qcom,msm-uartdm-v1.4", "qcom,msm-uartdm";
@@ -109,4 +119,7 @@ examples:
clock-names = "core", "iface";
dmas = <&dma0 0>, <&dma0 1>;
dma-names = "tx", "rx";
+ power-domains = <&rpmpd MSM8996_VDDCX>;
+ operating-points-v2 = <&uart_opp_table>;
+ interconnects = <&pnoc MASTER_BLSP_1 &bimc SLAVE_EBI_CH0>;
};
--
2.39.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] serial: msm: Use OPP table for DVFS support
2023-11-28 9:43 [PATCH 0/2] serial: msm: Allow scaling power domains and interconnect Stephan Gerhold
2023-11-28 9:43 ` [PATCH 1/2] dt-bindings: serial: qcom,msm-uartdm: Vote for shared resources Stephan Gerhold
@ 2023-11-28 9:43 ` Stephan Gerhold
1 sibling, 0 replies; 4+ messages in thread
From: Stephan Gerhold @ 2023-11-28 9:43 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Andy Gross, Bjorn Andersson, Konrad Dybcio, Jiri Slaby,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, linux-arm-msm,
linux-serial, devicetree, linux-kernel, Stephan Gerhold
Parse the OPP table from the device tree and use dev_pm_opp_set_rate()
instead of clk_set_rate() to allow making performance state votes
specified in the OPP table (e.g. for power domains and interconnects).
Without an OPP table in the device tree this will behave just as before
this patch.
Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
---
drivers/tty/serial/msm_serial.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index 7fc8f0b16aef..e24204ad35de 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -1131,7 +1132,7 @@ static int msm_set_baud_rate(struct uart_port *port, unsigned int baud,
uart_port_unlock_irqrestore(port, flags);
entry = msm_find_best_baud(port, baud, &rate);
- clk_set_rate(msm_port->clk, rate);
+ dev_pm_opp_set_rate(port->dev, rate);
baud = rate / 16 / entry->divisor;
uart_port_lock_irqsave(port, &flags);
@@ -1186,6 +1187,7 @@ static void msm_init_clock(struct uart_port *port)
{
struct msm_port *msm_port = to_msm_port(port);
+ dev_pm_opp_set_rate(port->dev, port->uartclk);
clk_prepare_enable(msm_port->clk);
clk_prepare_enable(msm_port->pclk);
msm_serial_set_mnd_regs(port);
@@ -1239,6 +1241,7 @@ static int msm_startup(struct uart_port *port)
clk_disable_unprepare(msm_port->pclk);
clk_disable_unprepare(msm_port->clk);
+ dev_pm_opp_set_rate(port->dev, 0);
return ret;
}
@@ -1254,6 +1257,7 @@ static void msm_shutdown(struct uart_port *port)
msm_release_dma(msm_port);
clk_disable_unprepare(msm_port->clk);
+ dev_pm_opp_set_rate(port->dev, 0);
free_irq(port->irq, port);
}
@@ -1419,11 +1423,13 @@ static void msm_power(struct uart_port *port, unsigned int state,
switch (state) {
case 0:
+ dev_pm_opp_set_rate(port->dev, port->uartclk);
clk_prepare_enable(msm_port->clk);
clk_prepare_enable(msm_port->pclk);
break;
case 3:
clk_disable_unprepare(msm_port->clk);
+ dev_pm_opp_set_rate(port->dev, 0);
clk_disable_unprepare(msm_port->pclk);
break;
default:
@@ -1789,7 +1795,7 @@ static int msm_serial_probe(struct platform_device *pdev)
struct resource *resource;
struct uart_port *port;
const struct of_device_id *id;
- int irq, line;
+ int irq, line, ret;
if (pdev->dev.of_node)
line = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -1824,6 +1830,15 @@ static int msm_serial_probe(struct platform_device *pdev)
return PTR_ERR(msm_port->pclk);
}
+ ret = devm_pm_opp_set_clkname(&pdev->dev, "core");
+ if (ret)
+ return ret;
+
+ /* OPP table is optional */
+ ret = devm_pm_opp_of_add_table(&pdev->dev);
+ if (ret && ret != -ENODEV)
+ return dev_err_probe(&pdev->dev, ret, "invalid OPP table\n");
+
port->uartclk = clk_get_rate(msm_port->clk);
dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk);
--
2.39.2
^ permalink raw reply related [flat|nested] 4+ messages in thread