fix(st-clock): adapt order of CSS on LSE and HSE
Fix the activation order of the CSS to prevent a faulty halt, according
to the reference manual (RM0442 Rev 6, Chapter: 10.4.3 Clock security
system CSS) it must be done after selecting the LSE clock via the RTCSRC
field.
For the HSE clock, this can be activated even when HSEON is '0'.
Signed-off-by: Christoph Fritz <chf@fritzc.com>
Signed-off-by: Gabriel Fernandez <gabriel.fernandez@foss.st.com>
Change-Id: Ied01baac1ccc63dcef78bf5f9180bb8628cce2d0
diff --git a/drivers/st/clk/stm32mp1_clk.c b/drivers/st/clk/stm32mp1_clk.c
index 705728f..1028a06 100644
--- a/drivers/st/clk/stm32mp1_clk.c
+++ b/drivers/st/clk/stm32mp1_clk.c
@@ -64,6 +64,7 @@
uint32_t *clksrc;
uint32_t nclkdiv;
uint32_t *clkdiv;
+ bool lse_css;
};
struct stm32_clk_priv {
@@ -2072,6 +2073,7 @@
uint32_t sel = (data & CLK_SEL_MASK) >> CLK_SEL_SHIFT;
uint32_t enable = (data & CLK_ON_MASK) >> CLK_ON_SHIFT;
unsigned long binding_id = ((unsigned long)data & CLK_ID_MASK) >> CLK_ID_SHIFT;
+ struct stm32_clk_platdata *pdata = priv->pdata;
if (binding_id == RTC) {
uintptr_t address = stm32mp_rcc_base() + RCC_BDCR;
@@ -2081,6 +2083,10 @@
(sel & RCC_SELR_SRC_MASK) << RCC_BDCR_RTCSRC_SHIFT);
mmio_setbits_32(address, RCC_BDCR_RTCCKEN);
+ /* Configure LSE CSS */
+ if (pdata->lse_css) {
+ mmio_setbits_32(priv->base + RCC_BDCR, RCC_BDCR_LSECSSON);
+ }
}
}
@@ -2176,7 +2182,6 @@
struct stm32_pll_dt_cfg *pll_conf = pdata->pll;
int ret;
enum stm32mp1_pll_id i;
- bool lse_css = false;
bool pll3_preserve = false;
bool pll4_preserve = false;
bool pll4_bootrom = false;
@@ -2209,7 +2214,7 @@
bypass = fdt_clk_read_bool(name, "st,bypass");
digbyp = fdt_clk_read_bool(name, "st,digbypass");
- lse_css = fdt_clk_read_bool(name, "st,css");
+ pdata->lse_css = fdt_clk_read_bool(name, "st,css");
lsedrv = fdt_clk_read_uint32_default(name, "st,drive",
LSEDRV_MEDIUM_HIGH);
stm32mp1_lse_enable(bypass, digbyp, lsedrv);
@@ -2382,10 +2387,6 @@
}
}
- if (lse_css) {
- mmio_setbits_32(priv->base + RCC_BDCR, RCC_BDCR_LSECSSON);
- }
-
/* Switch OFF HSI if not found in device-tree */
if (stm32mp1_osc[_HSI] == 0U) {
stm32mp1_hsi_set(false);