From 74a8397836e4dcdbca030d6affd93e30c092e94d Mon Sep 17 00:00:00 2001 From: Suman Anna Date: Thu, 22 Nov 2018 13:39:01 +0200 Subject: [PATCH] soc: ti: pruss: Configure SYSCFG properly during probe/remove The PRUSS CFG module's SYSCFG register is used for managing the PRCM clock management settings at the PRU-ICSS subsystem level. Add two helper functions pruss_{enable/disable}_module() that programs this SYSCFG register during probe and remove. The register is currently programmed for the default Smart-Idle and Smart-Standby always during probe. The MStandby is enabled during remove to undo the settings in probe to properly configure the SYSCFG in the case that a firmware has disabled MStandby. This is needed on SoCs like AM57xx that do not have a reset line and so cannot reset the register properly. Signed-off-by: Suman Anna Signed-off-by: Roger Quadros --- drivers/soc/ti/pruss_soc_bus.c | 60 ++++++++++++++++++++++++++++++---- 1 file changed, 54 insertions(+), 6 deletions(-) diff --git a/drivers/soc/ti/pruss_soc_bus.c b/drivers/soc/ti/pruss_soc_bus.c index afa55c9c9d94..ff1e0d0f59ef 100644 --- a/drivers/soc/ti/pruss_soc_bus.c +++ b/drivers/soc/ti/pruss_soc_bus.c @@ -20,6 +20,16 @@ #define SYSCFG_STANDBY_INIT BIT(4) #define SYSCFG_SUB_MWAIT_READY BIT(5) +#define SYSCFG_STANDBY_MODE_FORCE (0 << 2) +#define SYSCFG_STANDBY_MODE_NO (1 << 2) +#define SYSCFG_STANDBY_MODE_SMART (2 << 2) +#define SYSCFG_STANDBY_MODE_MASK (3 << 2) + +#define SYSCFG_IDLE_MODE_FORCE 0 +#define SYSCFG_IDLE_MODE_NO 1 +#define SYSCFG_IDLE_MODE_SMART 2 +#define SYSCFG_IDLE_MODE_MASK 3 + /** * struct pruss_soc_bus - PRUSS SoC bus structure * @syscfg: kernel mapped address for SYSCFG register @@ -115,6 +125,44 @@ static int __maybe_unused pruss_soc_bus_resume(struct device *dev) return ret; } +/* firmware must be idle when calling this function */ +static void pruss_disable_module(struct device *dev) +{ + struct pruss_soc_bus *psoc_bus = dev_get_drvdata(dev); + + /* configure Smart Standby */ + pruss_soc_bus_rmw(psoc_bus->syscfg, SYSCFG_STANDBY_MODE_MASK, + SYSCFG_STANDBY_MODE_SMART); + + /* initiate MStandby */ + pruss_soc_bus_rmw(psoc_bus->syscfg, SYSCFG_STANDBY_INIT, + SYSCFG_STANDBY_INIT); + + /* tell PRCM to initiate IDLE request */ + pm_runtime_put_sync(dev); +} + +static int pruss_enable_module(struct device *dev) +{ + struct pruss_soc_bus *psoc_bus = dev_get_drvdata(dev); + int ret; + + /* tell PRCM to de-assert IDLE request */ + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + pm_runtime_put_noidle(dev); + return ret; + } + + /* configure for Smart Idle & Smart Standby */ + pruss_soc_bus_rmw(psoc_bus->syscfg, SYSCFG_IDLE_MODE_MASK, + SYSCFG_IDLE_MODE_SMART); + pruss_soc_bus_rmw(psoc_bus->syscfg, SYSCFG_STANDBY_MODE_MASK, + SYSCFG_STANDBY_MODE_SMART); + + return ret; +} + static int pruss_soc_bus_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -155,10 +203,10 @@ static int pruss_soc_bus_probe(struct platform_device *pdev) } pm_runtime_enable(dev); - ret = pm_runtime_get_sync(dev); + ret = pruss_enable_module(dev); if (ret < 0) { - pm_runtime_put_noidle(dev); - goto fail_clock; + dev_err(dev, "couldn't enable module\n"); + goto fail_module; } ret = of_platform_populate(node, NULL, NULL, dev); @@ -168,8 +216,8 @@ static int pruss_soc_bus_probe(struct platform_device *pdev) return 0; fail_of: - pm_runtime_put_sync(dev); -fail_clock: + pruss_disable_module(dev); +fail_module: pm_runtime_disable(dev); if (psoc_bus->has_reset) pdata->assert_reset(pdev, pdata->reset_name); @@ -186,7 +234,7 @@ static int pruss_soc_bus_remove(struct platform_device *pdev) of_platform_depopulate(dev); - pm_runtime_put_sync(dev); + pruss_disable_module(dev); pm_runtime_disable(dev); if (psoc_bus->has_reset) -- 2.39.2