[ARM] 3866/1: AT91 clock update
This patch makes the AT91 clock.c support processor-generic (AT91RM9200
and AT91SAM9xxx). The clocks supported by a particular AT91 processor
are defined in the processor-specific file and are registered with
clock.c at startup.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-at91rm9200/clock.c b/arch/arm/mach-at91rm9200/clock.c
index 5b78922..a43b061 100644
--- a/arch/arm/mach-at91rm9200/clock.c
+++ b/arch/arm/mach-at91rm9200/clock.c
@@ -29,7 +29,7 @@
#include <asm/hardware.h>
-#include "generic.h"
+#include "clock.h"
/*
@@ -38,23 +38,15 @@
* PLLB be used at other rates (on boards that don't need USB), etc.
*/
-struct clk {
- const char *name; /* unique clock name */
- const char *function; /* function of the clock */
- struct device *dev; /* device associated with function */
- unsigned long rate_hz;
- struct clk *parent;
- u32 pmc_mask;
- void (*mode)(struct clk *, int);
- unsigned id:2; /* PCK0..3, or 32k/main/a/b */
- unsigned primary:1;
- unsigned pll:1;
- unsigned programmable:1;
- u16 users;
-};
+#define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY)
+#define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE)
+#define clk_is_peripheral(x) ((x)->type & CLK_TYPE_PERIPHERAL)
-static spinlock_t clk_lock;
-static u32 at91_pllb_usb_init;
+
+static LIST_HEAD(clocks);
+static DEFINE_SPINLOCK(clk_lock);
+
+static u32 at91_pllb_usb_init;
/*
* Four primary clock sources: two crystal oscillators (32K, main), and
@@ -67,21 +59,20 @@
.rate_hz = AT91_SLOW_CLOCK,
.users = 1, /* always on */
.id = 0,
- .primary = 1,
+ .type = CLK_TYPE_PRIMARY,
};
static struct clk main_clk = {
.name = "main",
.pmc_mask = AT91_PMC_MOSCS, /* in PMC_SR */
.id = 1,
- .primary = 1,
+ .type = CLK_TYPE_PRIMARY,
};
static struct clk plla = {
.name = "plla",
.parent = &main_clk,
.pmc_mask = AT91_PMC_LOCKA, /* in PMC_SR */
.id = 2,
- .primary = 1,
- .pll = 1,
+ .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
};
static void pllb_mode(struct clk *clk, int is_on)
@@ -94,6 +85,7 @@
} else
value = 0;
+ // REVISIT: Add work-around for AT91RM9200 Errata #26 ?
at91_sys_write(AT91_CKGR_PLLBR, value);
do {
@@ -107,8 +99,7 @@
.pmc_mask = AT91_PMC_LOCKB, /* in PMC_SR */
.mode = pllb_mode,
.id = 3,
- .primary = 1,
- .pll = 1,
+ .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL,
};
static void pmc_sys_mode(struct clk *clk, int is_on)
@@ -133,41 +124,6 @@
.mode = pmc_sys_mode,
};
-#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
-/*
- * The four programmable clocks can be parented by any primary clock.
- * You must configure pin multiplexing to bring these signals out.
- */
-static struct clk pck0 = {
- .name = "pck0",
- .pmc_mask = AT91_PMC_PCK0,
- .mode = pmc_sys_mode,
- .programmable = 1,
- .id = 0,
-};
-static struct clk pck1 = {
- .name = "pck1",
- .pmc_mask = AT91_PMC_PCK1,
- .mode = pmc_sys_mode,
- .programmable = 1,
- .id = 1,
-};
-static struct clk pck2 = {
- .name = "pck2",
- .pmc_mask = AT91_PMC_PCK2,
- .mode = pmc_sys_mode,
- .programmable = 1,
- .id = 2,
-};
-static struct clk pck3 = {
- .name = "pck3",
- .pmc_mask = AT91_PMC_PCK3,
- .mode = pmc_sys_mode,
- .programmable = 1,
- .id = 3,
-};
-#endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
-
/*
* The master clock is divided from the CPU clock (by 1-4). It's used for
@@ -187,131 +143,21 @@
at91_sys_write(AT91_PMC_PCDR, clk->pmc_mask);
}
-static struct clk udc_clk = {
- .name = "udc_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_UDP,
- .mode = pmc_periph_mode,
-};
-static struct clk ohci_clk = {
- .name = "ohci_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_UHP,
- .mode = pmc_periph_mode,
-};
-static struct clk ether_clk = {
- .name = "ether_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_EMAC,
- .mode = pmc_periph_mode,
-};
-static struct clk mmc_clk = {
- .name = "mci_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_MCI,
- .mode = pmc_periph_mode,
-};
-static struct clk twi_clk = {
- .name = "twi_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_TWI,
- .mode = pmc_periph_mode,
-};
-static struct clk usart0_clk = {
- .name = "usart0_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_US0,
- .mode = pmc_periph_mode,
-};
-static struct clk usart1_clk = {
- .name = "usart1_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_US1,
- .mode = pmc_periph_mode,
-};
-static struct clk usart2_clk = {
- .name = "usart2_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_US2,
- .mode = pmc_periph_mode,
-};
-static struct clk usart3_clk = {
- .name = "usart3_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_US3,
- .mode = pmc_periph_mode,
-};
-static struct clk spi_clk = {
- .name = "spi0_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_SPI,
- .mode = pmc_periph_mode,
-};
-static struct clk pioA_clk = {
- .name = "pioA_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_PIOA,
- .mode = pmc_periph_mode,
-};
-static struct clk pioB_clk = {
- .name = "pioB_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_PIOB,
- .mode = pmc_periph_mode,
-};
-static struct clk pioC_clk = {
- .name = "pioC_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_PIOC,
- .mode = pmc_periph_mode,
-};
-static struct clk pioD_clk = {
- .name = "pioD_clk",
- .parent = &mck,
- .pmc_mask = 1 << AT91RM9200_ID_PIOD,
- .mode = pmc_periph_mode,
-};
+static struct clk __init *at91_css_to_clk(unsigned long css)
+{
+ switch (css) {
+ case AT91_PMC_CSS_SLOW:
+ return &clk32k;
+ case AT91_PMC_CSS_MAIN:
+ return &main_clk;
+ case AT91_PMC_CSS_PLLA:
+ return &plla;
+ case AT91_PMC_CSS_PLLB:
+ return &pllb;
+ }
-static struct clk *const clock_list[] = {
- /* four primary clocks -- MUST BE FIRST! */
- &clk32k,
- &main_clk,
- &plla,
- &pllb,
-
- /* PLLB children (USB) */
- &udpck,
- &uhpck,
-
-#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
- /* programmable clocks */
- &pck0,
- &pck1,
- &pck2,
- &pck3,
-#endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
-
- /* MCK and peripherals */
- &mck,
- &usart0_clk,
- &usart1_clk,
- &usart2_clk,
- &usart3_clk,
- &mmc_clk,
- &udc_clk,
- &twi_clk,
- &spi_clk,
- &pioA_clk,
- &pioB_clk,
- &pioC_clk,
- &pioD_clk,
- // ssc0..ssc2
- // tc0..tc5
- // irq0..irq6
- &ohci_clk,
- ðer_clk,
-};
-
+ return NULL;
+}
/*
* Associate a particular clock with a function (eg, "uart") and device.
@@ -329,14 +175,12 @@
clk->dev = dev;
}
-/* clocks are all static for now; no refcounting necessary */
+/* clocks cannot be de-registered no refcounting necessary */
struct clk *clk_get(struct device *dev, const char *id)
{
- int i;
+ struct clk *clk;
- for (i = 0; i < ARRAY_SIZE(clock_list); i++) {
- struct clk *clk = clock_list[i];
-
+ list_for_each_entry(clk, &clocks, node) {
if (strcmp(id, clk->name) == 0)
return clk;
if (clk->function && (dev == clk->dev) && strcmp(id, clk->function) == 0)
@@ -424,7 +268,7 @@
unsigned prescale;
unsigned long actual;
- if (!clk->programmable)
+ if (!clk_is_programmable(clk))
return -EINVAL;
spin_lock_irqsave(&clk_lock, flags);
@@ -446,7 +290,7 @@
unsigned prescale;
unsigned long actual;
- if (!clk->programmable)
+ if (!clk_is_programmable(clk))
return -EINVAL;
if (clk->users)
return -EBUSY;
@@ -484,7 +328,7 @@
if (clk->users)
return -EBUSY;
- if (!parent->primary || !clk->programmable)
+ if (!clk_is_primary(parent) || !clk_is_programmable(clk))
return -EINVAL;
spin_lock_irqsave(&clk_lock, flags);
@@ -497,6 +341,18 @@
}
EXPORT_SYMBOL(clk_set_parent);
+/* establish PCK0..PCK3 parentage and rate */
+static void init_programmable_clock(struct clk *clk)
+{
+ struct clk *parent;
+ u32 pckr;
+
+ pckr = at91_sys_read(AT91_PMC_PCKR(clk->id));
+ parent = at91_css_to_clk(pckr & AT91_PMC_CSS);
+ clk->parent = parent;
+ clk->rate_hz = parent->rate_hz / (1 << ((pckr >> 2) & 3));
+}
+
#endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
/*------------------------------------------------------------------------*/
@@ -506,6 +362,7 @@
static int at91_clk_show(struct seq_file *s, void *unused)
{
u32 scsr, pcsr, sr;
+ struct clk *clk;
unsigned i;
seq_printf(s, "SCSR = %8x\n", scsr = at91_sys_read(AT91_PMC_SCSR));
@@ -523,9 +380,8 @@
seq_printf(s, "\n");
- for (i = 0; i < ARRAY_SIZE(clock_list); i++) {
- char *state;
- struct clk *clk = clock_list[i];
+ list_for_each_entry(clk, &clocks, node) {
+ char *state;
if (clk->mode == pmc_sys_mode)
state = (scsr & clk->pmc_mask) ? "on" : "off";
@@ -570,6 +426,28 @@
/*------------------------------------------------------------------------*/
+/* Register a new clock */
+int __init clk_register(struct clk *clk)
+{
+ if (clk_is_peripheral(clk)) {
+ clk->parent = &mck;
+ clk->mode = pmc_periph_mode;
+ list_add_tail(&clk->node, &clocks);
+ }
+#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
+ else if (clk_is_programmable(clk)) {
+ clk->mode = pmc_sys_mode;
+ init_programmable_clock(clk);
+ list_add_tail(&clk->node, &clocks);
+ }
+#endif
+
+ return 0;
+}
+
+
+/*------------------------------------------------------------------------*/
+
static u32 __init at91_pll_rate(struct clk *pll, u32 freq, u32 reg)
{
unsigned mul, div;
@@ -640,20 +518,17 @@
return 0;
}
-
/*
* Several unused clocks may be active. Turn them off.
*/
-static void at91_periphclk_reset(void)
+static void __init at91_periphclk_reset(void)
{
unsigned long reg;
- int i;
+ struct clk *clk;
reg = at91_sys_read(AT91_PMC_PCSR);
- for (i = 0; i < ARRAY_SIZE(clock_list); i++) {
- struct clk *clk = clock_list[i];
-
+ list_for_each_entry(clk, &clocks, node) {
if (clk->mode != pmc_periph_mode)
continue;
@@ -664,11 +539,25 @@
at91_sys_write(AT91_PMC_PCDR, reg);
}
+static struct clk *const standard_pmc_clocks[] __initdata = {
+ /* four primary clocks */
+ &clk32k,
+ &main_clk,
+ &plla,
+ &pllb,
+
+ /* PLLB children (USB) */
+ &udpck,
+ &uhpck,
+
+ /* MCK */
+ &mck
+};
+
int __init at91_clock_init(unsigned long main_clock)
{
unsigned tmp, freq, mckr;
-
- spin_lock_init(&clk_lock);
+ int i;
/*
* When the bootloader initialized the main oscillator correctly,
@@ -709,11 +598,15 @@
* For now, assume this parentage won't change.
*/
mckr = at91_sys_read(AT91_PMC_MCKR);
- mck.parent = clock_list[mckr & AT91_PMC_CSS];
+ mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
freq = mck.parent->rate_hz;
freq /= (1 << ((mckr >> 2) & 3)); /* prescale */
mck.rate_hz = freq / (1 + ((mckr >> 8) & 3)); /* mdiv */
+ /* Register the PMC's standard clocks */
+ for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++)
+ list_add_tail(&standard_pmc_clocks[i]->node, &clocks);
+
/* MCK and CPU clock are "always on" */
clk_enable(&mck);
@@ -722,35 +615,8 @@
(unsigned) main_clock / 1000000,
((unsigned) main_clock % 1000000) / 1000);
-#ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS
- /* establish PCK0..PCK3 parentage */
- for (tmp = 0; tmp < ARRAY_SIZE(clock_list); tmp++) {
- struct clk *clk = clock_list[tmp], *parent;
- u32 pckr;
-
- if (!clk->programmable)
- continue;
-
- pckr = at91_sys_read(AT91_PMC_PCKR(clk->id));
- parent = clock_list[pckr & AT91_PMC_CSS];
- clk->parent = parent;
- clk->rate_hz = parent->rate_hz / (1 << ((pckr >> 2) & 3));
-
- if (clk->users == 0) {
- /* not being used, so switch it off */
- at91_sys_write(AT91_PMC_SCDR, clk->pmc_mask);
- }
- }
-#else
/* disable all programmable clocks */
at91_sys_write(AT91_PMC_SCDR, AT91_PMC_PCK0 | AT91_PMC_PCK1 | AT91_PMC_PCK2 | AT91_PMC_PCK3);
-#endif
-
- /* enable the PIO clocks */
- clk_enable(&pioA_clk);
- clk_enable(&pioB_clk);
- clk_enable(&pioC_clk);
- clk_enable(&pioD_clk);
/* disable all other unused peripheral clocks */
at91_periphclk_reset();