From: Bich Hemon <bich.hemon@xxxxxx> Add support for wake-up from low power modes. This extends stm32f7. Introduce new compatible for stm32h7 to manage wake-up capability. Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx> --- drivers/tty/serial/stm32-usart.c | 90 +++++++++++++++++++++++++++++++++++++++- drivers/tty/serial/stm32-usart.h | 29 +++++++++++++ 2 files changed, 118 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index a62fc95..05d89b0 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -25,6 +25,7 @@ #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/pm_runtime.h> +#include <linux/pm_wakeirq.h> #include <linux/serial_core.h> #include <linux/serial.h> #include <linux/spinlock.h> @@ -374,6 +375,10 @@ static irqreturn_t stm32_interrupt(int irq, void *ptr) writel_relaxed(USART_ICR_RTOCF, port->membase + ofs->icr); + if ((sr & USART_SR_WUF) && (ofs->icr != UNDEF_REG)) + writel_relaxed(USART_ICR_WUCF, + port->membase + ofs->icr); + if ((sr & USART_SR_RXNE) && !(stm32_port->rx_ch)) stm32_receive_chars(port, false); @@ -526,6 +531,7 @@ static int stm32_startup(struct uart_port *port) { struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + struct stm32_usart_config *cfg = &stm32_port->info->cfg; const char *name = to_platform_device(port->dev)->name; u32 val; int ret; @@ -536,6 +542,15 @@ static int stm32_startup(struct uart_port *port) if (ret) return ret; + if (cfg->has_wakeup && stm32_port->wakeirq >= 0) { + ret = dev_pm_set_dedicated_wake_irq(port->dev, + stm32_port->wakeirq); + if (ret) { + free_irq(port->irq, port); + return ret; + } + } + val = stm32_port->rx_irq | USART_CR1_TE | USART_CR1_RE; if (stm32_port->fifoen) val |= USART_CR1_FIFOEN; @@ -558,6 +573,7 @@ static void stm32_shutdown(struct uart_port *port) val |= USART_CR1_FIFOEN; stm32_clr_bits(port, ofs->cr1, val); + dev_pm_clear_wake_irq(port->dev); free_irq(port->irq, port); } @@ -758,6 +774,7 @@ static int stm32_init_port(struct stm32_port *stm32port, port->ops = &stm32_uart_ops; port->dev = &pdev->dev; port->irq = platform_get_irq(pdev, 0); + stm32port->wakeirq = platform_get_irq(pdev, 1); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); port->membase = devm_ioremap_resource(&pdev->dev, res); @@ -819,6 +836,8 @@ static struct stm32_port *stm32_of_get_stm32_port(struct platform_device *pdev) { .compatible = "st,stm32-uart", .data = &stm32f4_info}, { .compatible = "st,stm32f7-usart", .data = &stm32f7_info}, { .compatible = "st,stm32f7-uart", .data = &stm32f7_info}, + { .compatible = "st,stm32h7-usart", .data = &stm32h7_info}, + { .compatible = "st,stm32h7-uart", .data = &stm32h7_info}, {}, }; @@ -964,9 +983,15 @@ static int stm32_serial_probe(struct platform_device *pdev) if (ret) return ret; + if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0) { + ret = device_init_wakeup(&pdev->dev, true); + if (ret) + goto err_uninit; + } + ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port); if (ret) - goto err_uninit; + goto err_nowup; ret = stm32_of_dma_rx_probe(stm32port, pdev); if (ret) @@ -980,6 +1005,10 @@ static int stm32_serial_probe(struct platform_device *pdev) return 0; +err_nowup: + if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0) + device_init_wakeup(&pdev->dev, false); + err_uninit: clk_disable_unprepare(stm32port->clk); @@ -991,6 +1020,7 @@ static int stm32_serial_remove(struct platform_device *pdev) struct uart_port *port = platform_get_drvdata(pdev); struct stm32_port *stm32_port = to_stm32_port(port); struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + struct stm32_usart_config *cfg = &stm32_port->info->cfg; stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR); @@ -1016,6 +1046,9 @@ static int stm32_serial_remove(struct platform_device *pdev) TX_BUF_L, stm32_port->tx_buf, stm32_port->tx_dma_buf); + if (cfg->has_wakeup && stm32_port->wakeirq >= 0) + device_init_wakeup(&pdev->dev, false); + clk_disable_unprepare(stm32_port->clk); stm32_serial_debugfs_rm(stm32_port); @@ -1123,11 +1156,66 @@ static int stm32_console_setup(struct console *co, char *options) .cons = STM32_SERIAL_CONSOLE, }; +#ifdef CONFIG_PM_SLEEP +static void stm32_serial_enable_wakeup(struct uart_port *port, bool enable) +{ + struct stm32_port *stm32_port = to_stm32_port(port); + struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + struct stm32_usart_config *cfg = &stm32_port->info->cfg; + u32 val; + + if (!cfg->has_wakeup || stm32_port->wakeirq < 0) + return; + + if (enable) { + stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); + stm32_set_bits(port, ofs->cr1, USART_CR1_UESM); + val = readl_relaxed(port->membase + ofs->cr3); + val &= ~USART_CR3_WUS_MASK; + /* Enable Wake up interrupt from low power on start bit */ + val |= USART_CR3_WUS_START_BIT | USART_CR3_WUFIE; + writel_relaxed(val, port->membase + ofs->cr3); + stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); + } else { + stm32_clr_bits(port, ofs->cr1, USART_CR1_UESM); + } +} + +static int stm32_serial_suspend(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + uart_suspend_port(&stm32_usart_driver, port); + + if (device_may_wakeup(dev)) + stm32_serial_enable_wakeup(port, true); + else + stm32_serial_enable_wakeup(port, false); + + return 0; +} + +static int stm32_serial_resume(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + stm32_serial_enable_wakeup(port, false); + + return uart_resume_port(&stm32_usart_driver, port); +} +#endif /* CONFIG_PM_SLEEP */ + +static const struct dev_pm_ops stm32_serial_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(stm32_serial_suspend, stm32_serial_resume) +}; + static struct platform_driver stm32_serial_driver = { .probe = stm32_serial_probe, .remove = stm32_serial_remove, .driver = { .name = DRIVER_NAME, + .pm = &stm32_serial_pm_ops, .of_match_table = of_match_ptr(stm32_match), }, }; diff --git a/drivers/tty/serial/stm32-usart.h b/drivers/tty/serial/stm32-usart.h index 056a837..98dbf38 100644 --- a/drivers/tty/serial/stm32-usart.h +++ b/drivers/tty/serial/stm32-usart.h @@ -24,6 +24,7 @@ struct stm32_usart_offsets { struct stm32_usart_config { u8 uart_enable_bit; /* USART_CR1_UE */ bool has_7bits_data; + bool has_wakeup; }; struct stm32_usart_info { @@ -74,6 +75,27 @@ struct stm32_usart_info stm32f7_info = { } }; +struct stm32_usart_info stm32h7_info = { + .ofs = { + .cr1 = 0x00, + .cr2 = 0x04, + .cr3 = 0x08, + .brr = 0x0c, + .gtpr = 0x10, + .rtor = 0x14, + .rqr = 0x18, + .isr = 0x1c, + .icr = 0x20, + .rdr = 0x24, + .tdr = 0x28, + }, + .cfg = { + .uart_enable_bit = 0, + .has_7bits_data = true, + .has_wakeup = true, + } +}; + /* USART_SR (F4) / USART_ISR (F7) */ #define USART_SR_PE BIT(0) #define USART_SR_FE BIT(1) @@ -93,6 +115,7 @@ struct stm32_usart_info stm32f7_info = { #define USART_SR_BUSY BIT(16) /* F7 */ #define USART_SR_CMF BIT(17) /* F7 */ #define USART_SR_SBKF BIT(18) /* F7 */ +#define USART_SR_WUF BIT(20) /* H7 */ #define USART_SR_TEACK BIT(21) /* F7 */ #define USART_SR_ERR_MASK (USART_SR_LBD | USART_SR_ORE | \ USART_SR_FE | USART_SR_PE) @@ -113,6 +136,7 @@ struct stm32_usart_info stm32f7_info = { /* USART_CR1 */ #define USART_CR1_SBK BIT(0) #define USART_CR1_RWU BIT(1) /* F4 */ +#define USART_CR1_UESM BIT(1) /* H7 */ #define USART_CR1_RE BIT(2) #define USART_CR1_TE BIT(3) #define USART_CR1_IDLEIE BIT(4) @@ -176,6 +200,9 @@ struct stm32_usart_info stm32f7_info = { #define USART_CR3_DEM BIT(14) /* F7 */ #define USART_CR3_DEP BIT(15) /* F7 */ #define USART_CR3_SCARCNT_MASK GENMASK(19, 17) /* F7 */ +#define USART_CR3_WUS_MASK GENMASK(21, 20) /* H7 */ +#define USART_CR3_WUS_START_BIT BIT(21) /* H7 */ +#define USART_CR3_WUFIE BIT(22) /* H7 */ /* USART_GTPR */ #define USART_GTPR_PSC_MASK GENMASK(7, 0) @@ -204,6 +231,7 @@ struct stm32_usart_info stm32f7_info = { #define USART_ICR_RTOCF BIT(11) /* F7 */ #define USART_ICR_EOBCF BIT(12) /* F7 */ #define USART_ICR_CMCF BIT(17) /* F7 */ +#define USART_ICR_WUCF BIT(20) /* H7 */ #define STM32_SERIAL_NAME "ttyS" #define STM32_MAX_PORTS 8 @@ -230,6 +258,7 @@ struct stm32_port { bool tx_dma_busy; /* dma tx busy */ bool hw_flow_control; bool fifoen; + int wakeirq; }; static struct stm32_port stm32_ports[STM32_MAX_PORTS]; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html