diff options
Diffstat (limited to 'drivers/rtc/rtc-stm32.c')
| -rw-r--r-- | drivers/rtc/rtc-stm32.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c index 76753c71d92e..98b07969609d 100644 --- a/drivers/rtc/rtc-stm32.c +++ b/drivers/rtc/rtc-stm32.c @@ -5,6 +5,7 @@ */ #include <linux/bcd.h> +#include <linux/bitfield.h> #include <linux/clk.h> #include <linux/errno.h> #include <linux/iopoll.h> @@ -83,6 +84,18 @@ #define STM32_RTC_VERR_MAJREV_SHIFT 4 #define STM32_RTC_VERR_MAJREV GENMASK(7, 4) +/* STM32_RTC_SECCFGR bit fields */ +#define STM32_RTC_SECCFGR 0x20 +#define STM32_RTC_SECCFGR_ALRA_SEC BIT(0) +#define STM32_RTC_SECCFGR_INIT_SEC BIT(14) +#define STM32_RTC_SECCFGR_SEC BIT(15) + +/* STM32_RTC_RXCIDCFGR bit fields */ +#define STM32_RTC_RXCIDCFGR(x) (0x80 + 0x4 * (x)) +#define STM32_RTC_RXCIDCFGR_CFEN BIT(0) +#define STM32_RTC_RXCIDCFGR_CID GENMASK(6, 4) +#define STM32_RTC_RXCIDCFGR_CID1 1 + /* STM32_RTC_WPR key constants */ #define RTC_WPR_1ST_KEY 0xCA #define RTC_WPR_2ND_KEY 0x53 @@ -120,6 +133,7 @@ struct stm32_rtc_data { bool has_pclk; bool need_dbp; bool need_accuracy; + bool rif_protected; }; struct stm32_rtc { @@ -134,6 +148,14 @@ struct stm32_rtc { int irq_alarm; }; +struct stm32_rtc_rif_resource { + unsigned int num; + u32 bit; +}; + +static const struct stm32_rtc_rif_resource STM32_RTC_RES_ALRA = {0, STM32_RTC_SECCFGR_ALRA_SEC}; +static const struct stm32_rtc_rif_resource STM32_RTC_RES_INIT = {5, STM32_RTC_SECCFGR_INIT_SEC}; + static void stm32_rtc_wpr_unlock(struct stm32_rtc *rtc) { const struct stm32_rtc_registers *regs = &rtc->data->regs; @@ -553,6 +575,7 @@ static const struct stm32_rtc_data stm32_rtc_data = { .has_pclk = false, .need_dbp = true, .need_accuracy = false, + .rif_protected = false, .regs = { .tr = 0x00, .dr = 0x04, @@ -575,6 +598,7 @@ static const struct stm32_rtc_data stm32h7_rtc_data = { .has_pclk = true, .need_dbp = true, .need_accuracy = false, + .rif_protected = false, .regs = { .tr = 0x00, .dr = 0x04, @@ -606,6 +630,7 @@ static const struct stm32_rtc_data stm32mp1_data = { .has_pclk = true, .need_dbp = false, .need_accuracy = true, + .rif_protected = false, .regs = { .tr = 0x00, .dr = 0x04, @@ -624,14 +649,57 @@ static const struct stm32_rtc_data stm32mp1_data = { .clear_events = stm32mp1_rtc_clear_events, }; +static const struct stm32_rtc_data stm32mp25_data = { + .has_pclk = true, + .need_dbp = false, + .need_accuracy = true, + .rif_protected = true, + .regs = { + .tr = 0x00, + .dr = 0x04, + .cr = 0x18, + .isr = 0x0C, /* named RTC_ICSR on stm32mp25 */ + .prer = 0x10, + .alrmar = 0x40, + .wpr = 0x24, + .sr = 0x50, + .scr = 0x5C, + .verr = 0x3F4, + }, + .events = { + .alra = STM32_RTC_SR_ALRA, + }, + .clear_events = stm32mp1_rtc_clear_events, +}; + static const struct of_device_id stm32_rtc_of_match[] = { { .compatible = "st,stm32-rtc", .data = &stm32_rtc_data }, { .compatible = "st,stm32h7-rtc", .data = &stm32h7_rtc_data }, { .compatible = "st,stm32mp1-rtc", .data = &stm32mp1_data }, + { .compatible = "st,stm32mp25-rtc", .data = &stm32mp25_data }, {} }; MODULE_DEVICE_TABLE(of, stm32_rtc_of_match); +static int stm32_rtc_check_rif(struct stm32_rtc *stm32_rtc, + struct stm32_rtc_rif_resource res) +{ + u32 rxcidcfgr = readl_relaxed(stm32_rtc->base + STM32_RTC_RXCIDCFGR(res.num)); + u32 seccfgr; + + /* Check if RTC available for our CID */ + if ((rxcidcfgr & STM32_RTC_RXCIDCFGR_CFEN) && + (FIELD_GET(STM32_RTC_RXCIDCFGR_CID, rxcidcfgr) != STM32_RTC_RXCIDCFGR_CID1)) + return -EACCES; + + /* Check if RTC available for non secure world */ + seccfgr = readl_relaxed(stm32_rtc->base + STM32_RTC_SECCFGR); + if ((seccfgr & STM32_RTC_SECCFGR_SEC) | (seccfgr & res.bit)) + return -EACCES; + + return 0; +} + static int stm32_rtc_init(struct platform_device *pdev, struct stm32_rtc *rtc) { @@ -787,6 +855,16 @@ static int stm32_rtc_probe(struct platform_device *pdev) regmap_update_bits(rtc->dbp, rtc->dbp_reg, rtc->dbp_mask, rtc->dbp_mask); + if (rtc->data->rif_protected) { + ret = stm32_rtc_check_rif(rtc, STM32_RTC_RES_INIT); + if (!ret) + ret = stm32_rtc_check_rif(rtc, STM32_RTC_RES_ALRA); + if (ret) { + dev_err(&pdev->dev, "Failed to probe RTC due to RIF configuration\n"); + goto err; + } + } + /* * After a system reset, RTC_ISR.INITS flag can be read to check if * the calendar has been initialized or not. INITS flag is reset by a |