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soc: atmel: sam4l: Enable RC32K osc

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Enable sam4l internal factory calibrated RC32K clock source.  The RC32K
was used as source for Generic Clock 5 using 32 as divider.  The output
is a 1024 Hz clock that can be used by GLOC and TC0 peripherals.

Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
This commit is contained in:
Gerson Fernando Budke 2021-06-18 22:06:36 -03:00 • committed by Benjamin Cabé
commit 45ad5f89b0
2 changed files with 91 additions and 12 deletions
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33
soc/atmel/sam/sam4l/soc.c
View file

@ -56,6 +56,19 @@ static inline bool osc_is_ready(uint8_t id)
}
}
/**
* Enable Backup System Control Oscilator RC32K
*/
static inline void osc_priv_enable_rc32k(void)
{
uint32_t temp = BSCIF->RC32KCR;
uint32_t addr = (uint32_t)&BSCIF->RC32KCR - (uint32_t)BSCIF;
BSCIF->UNLOCK = BSCIF_UNLOCK_KEY(0xAAu)
| BSCIF_UNLOCK_ADDR(addr);
BSCIF->RC32KCR = temp | BSCIF_RC32KCR_EN32K | BSCIF_RC32KCR_EN;
}
/**
* The PLL options #PLL_OPT_VCO_RANGE_HIGH and #PLL_OPT_OUTPUT_DIV will
* be set automatically based on the calculated target frequency.
@ -153,6 +166,8 @@ static inline void flashcalw_issue_command(uint32_t command, int page_number)
*/
static ALWAYS_INLINE void clock_init(void)
{
uint32_t gen_clk_conf;
/* Disable PicoCache and Enable HRAMC1 as extended RAM */
soc_pmc_peripheral_enable(
PM_CLOCK_MASK(PM_CLK_GRP_HSB, SYSCLK_HRAMC1_DATA));
@ -224,6 +239,24 @@ static ALWAYS_INLINE void clock_init(void)
PM->UNLOCK = PM_UNLOCK_KEY(0xAAu) |
PM_UNLOCK_ADDR((uint32_t)&PM->MCCTRL - (uint32_t)PM);
PM->MCCTRL = OSC_SRC_PLL0;
/** Enable RC32K Oscilator */
osc_priv_enable_rc32k();
while (!osc_is_ready(OSC_ID_RC32K)) {
;
}
/** Enable Generic Clock 5
* Source: RC32K
* Div: 32
* Clk: 1024 Hz
* The GCLK-5 can be used by GLOC, TC0 and RC32KIFB_REF
*/
gen_clk_conf = SCIF_GCCTRL_RESETVALUE;
gen_clk_conf |= SCIF_GCCTRL_OSCSEL(GEN_CLK_SRC_RC32K);
gen_clk_conf |= SCIF_GCCTRL_DIVEN;
gen_clk_conf |= SCIF_GCCTRL_DIV(((32 + 1) / 2) - 1);
SCIF->GCCTRL[GEN_CLK_TC0_GLOC_RC32] = gen_clk_conf | SCIF_GCCTRL_CEN;
}
void soc_reset_hook(void)

48
soc/atmel/sam/sam4l/soc.h
View file

@ -213,7 +213,7 @@
#define GEN_CLK_AST 2
#define GEN_CLK_CATB 3
#define GEN_CLK_AESA 4
#define GEN_CLK_GLOC 5
#define GEN_CLK_TC0_GLOC_RC32 5
#define GEN_CLK_ABDACB 6
#define GEN_CLK_USBC 7
#define GEN_CLK_TC1_PEVC0 8
@ -221,6 +221,52 @@
#define GEN_CLK_ADCIFE 10
#define GEN_CLK_MASTER_GEN 11
/**
* 0- System RC oscillator
* 1- 32 kHz oscillator
* 2- DFLL
* 3- Oscillator 0
* 4- 80 MHz RC oscillator
* 5- 4-8-12 MHz RC oscillator
* 6- 1 MHz RC oscillator
* 7- CPU clock
* 8- High Speed Bus clock
* 9- Peripheral Bus A clock
* 10- Peripheral Bus B clock
* 11- Peripheral Bus C clock
* 12- Peripheral Bus D clock
* 13- 32 kHz RC oscillator
* 15- 1 kHz output from OSC32K
* 16- PLL0
* 17- High resolution prescaler
* 18- Fractional prescaler
* 19- GCLKIN0
* 20- GCLKIN1
* 21- GCLK11
*/
#define GEN_CLK_SRC_RCSYS 0
#define GEN_CLK_SRC_OSC32K 1
#define GEN_CLK_SRC_DFLL 2
#define GEN_CLK_SRC_OSC0 3
#define GEN_CLK_SRC_RC80M 4
#define GEN_CLK_SRC_RCFAST 5
#define GEN_CLK_SRC_RC1M 6
#define GEN_CLK_SRC_CLK_CPU 7
#define GEN_CLK_SRC_CLK_HSB 8
#define GEN_CLK_SRC_CLK_PBA 9
#define GEN_CLK_SRC_CLK_PBB 10
#define GEN_CLK_SRC_CLK_PBC 11
#define GEN_CLK_SRC_CLK_PBD 12
#define GEN_CLK_SRC_RC32K 13
#define GEN_CLK_SRC_CLK_1K 15
#define GEN_CLK_SRC_PLL0 16
#define GEN_CLK_SRC_HRPCLK 17
#define GEN_CLK_SRC_FPCLK 18
#define GEN_CLK_SRC_GCLKIN0 19
#define GEN_CLK_SRC_GCLKIN1 20
#define GEN_CLK_SRC_GCLK11 21
#endif /* !_ASMLANGUAGE */
#endif /* _SOC_ATMEL_SAM_SAM4L_SOC_H_ */