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[ARM] 5438/1: AT91: manage clock by functionality instead of CPUs
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In clock.c file the clock management is grouped by cpu with cpu_is_xxx()
function. This lead to some kind of difficulties to read this file and
maintainability issues as the number of AT91 cpus & PLLs/clocks is growing.

In this patch, I try to group clock functionality together and match cpus with
this functionality set.
An update to at91_pmc.h is needed to cover some new PMC possibilities (and
some update in comments).

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Andrew Victor <avictor.za@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Nicolas Ferre authored and Russell King committed Apr 28, 2009
1 parent b4175b8 commit 6d0485a
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Showing 2 changed files with 132 additions and 45 deletions.
151 changes: 112 additions & 39 deletions arch/arm/mach-at91/clock.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,25 @@
#define clk_is_sys(x) ((x)->type & CLK_TYPE_SYSTEM)


/*
* Chips have some kind of clocks : group them by functionality
*/
#define cpu_has_utmi() ( cpu_is_at91cap9() \
|| cpu_is_at91sam9rl())

#define cpu_has_800M_plla() (cpu_is_at91sam9g20())

#define cpu_has_pllb() (!cpu_is_at91sam9rl())

#define cpu_has_upll() (0)

/* USB host HS & FS */
#define cpu_has_uhp() (!cpu_is_at91sam9rl())

/* USB device FS only */
#define cpu_has_udpfs() (!cpu_is_at91sam9rl())


static LIST_HEAD(clocks);
static DEFINE_SPINLOCK(clk_lock);

Expand Down Expand Up @@ -140,7 +159,7 @@ static struct clk utmi_clk = {
};
static struct clk uhpck = {
.name = "uhpck",
.parent = &pllb,
/*.parent = ... we choose parent at runtime */
.mode = pmc_sys_mode,
};

Expand Down Expand Up @@ -173,7 +192,11 @@ static struct clk __init *at91_css_to_clk(unsigned long css)
case AT91_PMC_CSS_PLLA:
return &plla;
case AT91_PMC_CSS_PLLB:
return &pllb;
if (cpu_has_upll())
/* CSS_PLLB == CSS_UPLL */
return &utmi_clk;
else if (cpu_has_pllb())
return &pllb;
}

return NULL;
Expand Down Expand Up @@ -322,7 +345,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
u32 pckr;

pckr = at91_sys_read(AT91_PMC_PCKR(clk->id));
pckr &= AT91_PMC_CSS_PLLB; /* clock selection */
pckr &= AT91_PMC_CSS; /* clock selection */
pckr |= prescale << 2;
at91_sys_write(AT91_PMC_PCKR(clk->id), pckr);
clk->rate_hz = actual;
Expand Down Expand Up @@ -361,7 +384,7 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
}
EXPORT_SYMBOL(clk_set_parent);

/* establish PCK0..PCK3 parentage and rate */
/* establish PCK0..PCKN parentage and rate */
static void __init init_programmable_clock(struct clk *clk)
{
struct clk *parent;
Expand Down Expand Up @@ -389,11 +412,13 @@ static int at91_clk_show(struct seq_file *s, void *unused)
seq_printf(s, "MOR = %8x\n", at91_sys_read(AT91_CKGR_MOR));
seq_printf(s, "MCFR = %8x\n", at91_sys_read(AT91_CKGR_MCFR));
seq_printf(s, "PLLA = %8x\n", at91_sys_read(AT91_CKGR_PLLAR));
if (!cpu_is_at91sam9rl())
if (cpu_has_pllb())
seq_printf(s, "PLLB = %8x\n", at91_sys_read(AT91_CKGR_PLLBR));
if (cpu_is_at91cap9() || cpu_is_at91sam9rl())
if (cpu_has_utmi())
seq_printf(s, "UCKR = %8x\n", uckr = at91_sys_read(AT91_CKGR_UCKR));
seq_printf(s, "MCKR = %8x\n", at91_sys_read(AT91_PMC_MCKR));
if (cpu_has_upll())
seq_printf(s, "USB = %8x\n", at91_sys_read(AT91_PMC_USB));
seq_printf(s, "SR = %8x\n", sr = at91_sys_read(AT91_PMC_SR));

seq_printf(s, "\n");
Expand Down Expand Up @@ -554,16 +579,60 @@ static struct clk *const standard_pmc_clocks[] __initdata = {
&clk32k,
&main_clk,
&plla,
&pllb,

/* PLLB children (USB) */
&udpck,
&uhpck,

/* MCK */
&mck
};

/* PLLB generated USB full speed clock init */
static void __init at91_pllb_usbfs_clock_init(unsigned long main_clock)
{
/*
* USB clock init: choose 48 MHz PLLB value,
* disable 48MHz clock during usb peripheral suspend.
*
* REVISIT: assumes MCK doesn't derive from PLLB!
*/
uhpck.parent = &pllb;

at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M;
pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init);
if (cpu_is_at91rm9200()) {
uhpck.pmc_mask = AT91RM9200_PMC_UHP;
udpck.pmc_mask = AT91RM9200_PMC_UDP;
at91_sys_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
} else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263() || cpu_is_at91sam9g20()) {
uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
udpck.pmc_mask = AT91SAM926x_PMC_UDP;
} else if (cpu_is_at91cap9()) {
uhpck.pmc_mask = AT91CAP9_PMC_UHP;
}
at91_sys_write(AT91_CKGR_PLLBR, 0);

udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
}

/* UPLL generated USB full speed clock init */
static void __init at91_upll_usbfs_clock_init(unsigned long main_clock)
{
/*
* USB clock init: choose 480 MHz from UPLL,
*/
unsigned int usbr = AT91_PMC_USBS_UPLL;

/* Setup divider by 10 to reach 48 MHz */
usbr |= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV;

at91_sys_write(AT91_PMC_USB, usbr);

/* Now set uhpck values */
uhpck.parent = &utmi_clk;
uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
uhpck.rate_hz = utmi_clk.parent->rate_hz;
uhpck.rate_hz /= 1 + ((at91_sys_read(AT91_PMC_USB) & AT91_PMC_OHCIUSBDIV) >> 8);
}

int __init at91_clock_init(unsigned long main_clock)
{
unsigned tmp, freq, mckr;
Expand All @@ -585,43 +654,37 @@ int __init at91_clock_init(unsigned long main_clock)

/* report if PLLA is more than mildly overclocked */
plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_sys_read(AT91_CKGR_PLLAR));
if ((!cpu_is_at91sam9g20() && plla.rate_hz > 209000000)
|| (cpu_is_at91sam9g20() && plla.rate_hz > 800000000))
if ((!cpu_has_800M_plla() && plla.rate_hz > 209000000)
|| (cpu_has_800M_plla() && plla.rate_hz > 800000000))
pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);

/*
* USB clock init: choose 48 MHz PLLB value,
* disable 48MHz clock during usb peripheral suspend.
*
* REVISIT: assumes MCK doesn't derive from PLLB!
*/
at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M;
pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init);
if (cpu_is_at91rm9200()) {
uhpck.pmc_mask = AT91RM9200_PMC_UHP;
udpck.pmc_mask = AT91RM9200_PMC_UDP;
at91_sys_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
} else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263() || cpu_is_at91sam9g20()) {
uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
udpck.pmc_mask = AT91SAM926x_PMC_UDP;
} else if (cpu_is_at91cap9()) {
uhpck.pmc_mask = AT91CAP9_PMC_UHP;

if (cpu_has_upll() && !cpu_has_pllb()) {
/* setup UTMI clock as the fourth primary clock
* (instead of pllb) */
utmi_clk.type |= CLK_TYPE_PRIMARY;
utmi_clk.id = 3;
}
at91_sys_write(AT91_CKGR_PLLBR, 0);

udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);
uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init);

/*
* USB HS clock init
*/
if (cpu_is_at91cap9() || cpu_is_at91sam9rl()) {
if (cpu_has_utmi())
/*
* multiplier is hard-wired to 40
* (obtain the USB High Speed 480 MHz when input is 12 MHz)
*/
utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz;
}

/*
* USB FS clock init
*/
if (cpu_has_pllb())
at91_pllb_usbfs_clock_init(main_clock);
if (cpu_has_upll())
/* assumes that we choose UPLL for USB and not PLLA */
at91_upll_usbfs_clock_init(main_clock);

/*
* MCK and CPU derive from one of those primary clocks.
Expand All @@ -631,21 +694,31 @@ int __init at91_clock_init(unsigned long main_clock)
mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS);
freq = mck.parent->rate_hz;
freq /= (1 << ((mckr & AT91_PMC_PRES) >> 2)); /* prescale */
if (cpu_is_at91rm9200())
if (cpu_is_at91rm9200()) {
mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */
else if (cpu_is_at91sam9g20()) {
} else if (cpu_is_at91sam9g20()) {
mck.rate_hz = (mckr & AT91_PMC_MDIV) ?
freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */
if (mckr & AT91_PMC_PDIV)
freq /= 2; /* processor clock division */
} else
} else {
mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* 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);

if (cpu_is_at91cap9() || cpu_is_at91sam9rl())
if (cpu_has_pllb())
list_add_tail(&pllb.node, &clocks);

if (cpu_has_uhp())
list_add_tail(&uhpck.node, &clocks);

if (cpu_has_udpfs())
list_add_tail(&udpck.node, &clocks);

if (cpu_has_utmi())
list_add_tail(&utmi_clk.node, &clocks);

/* MCK and CPU clock are "always on" */
Expand Down
26 changes: 20 additions & 6 deletions arch/arm/mach-at91/include/mach/at91_pmc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@
#define AT91_PMC_PCK (1 << 0) /* Processor Clock */
#define AT91RM9200_PMC_UDP (1 << 1) /* USB Devcice Port Clock [AT91RM9200 only] */
#define AT91RM9200_PMC_MCKUDP (1 << 2) /* USB Device Port Master Clock Automatic Disable on Suspend [AT91RM9200 only] */
#define AT91CAP9_PMC_DDR (1 << 2) /* DDR Clock [AT91CAP9 revC only] */
#define AT91CAP9_PMC_DDR (1 << 2) /* DDR Clock [CAP9 revC & some SAM9 only] */
#define AT91RM9200_PMC_UHP (1 << 4) /* USB Host Port Clock [AT91RM9200 only] */
#define AT91SAM926x_PMC_UHP (1 << 6) /* USB Host Port Clock [AT91SAM926x only] */
#define AT91CAP9_PMC_UHP (1 << 6) /* USB Host Port Clock [AT91CAP9 only] */
Expand All @@ -39,11 +39,11 @@
#define AT91_PMC_PCDR (AT91_PMC + 0x14) /* Peripheral Clock Disable Register */
#define AT91_PMC_PCSR (AT91_PMC + 0x18) /* Peripheral Clock Status Register */

#define AT91_CKGR_UCKR (AT91_PMC + 0x1C) /* UTMI Clock Register [SAM9RL, CAP9] */
#define AT91_CKGR_UCKR (AT91_PMC + 0x1C) /* UTMI Clock Register [some SAM9, CAP9] */
#define AT91_PMC_UPLLEN (1 << 16) /* UTMI PLL Enable */
#define AT91_PMC_UPLLCOUNT (0xf << 20) /* UTMI PLL Start-up Time */
#define AT91_PMC_BIASEN (1 << 24) /* UTMI BIAS Enable */
#define AT91_PMC_BIASCOUNT (0xf << 28) /* UTMI PLL Start-up Time */
#define AT91_PMC_BIASCOUNT (0xf << 28) /* UTMI BIAS Start-up Time */

#define AT91_CKGR_MOR (AT91_PMC + 0x20) /* Main Oscillator Register [not on SAM9RL] */
#define AT91_PMC_MOSCEN (1 << 0) /* Main Oscillator Enable */
Expand Down Expand Up @@ -72,6 +72,7 @@
#define AT91_PMC_CSS_MAIN (1 << 0)
#define AT91_PMC_CSS_PLLA (2 << 0)
#define AT91_PMC_CSS_PLLB (3 << 0)
#define AT91_PMC_CSS_UPLL (3 << 0) /* [some SAM9 only] */
#define AT91_PMC_PRES (7 << 2) /* Master Clock Prescaler */
#define AT91_PMC_PRES_1 (0 << 2)
#define AT91_PMC_PRES_2 (1 << 2)
Expand All @@ -88,12 +89,25 @@
#define AT91SAM9_PMC_MDIV_1 (0 << 8) /* [SAM9,CAP9 only] */
#define AT91SAM9_PMC_MDIV_2 (1 << 8)
#define AT91SAM9_PMC_MDIV_4 (2 << 8)
#define AT91SAM9_PMC_MDIV_6 (3 << 8)
#define AT91SAM9_PMC_MDIV_6 (3 << 8) /* [some SAM9 only] */
#define AT91SAM9_PMC_MDIV_3 (3 << 8) /* [some SAM9 only] */
#define AT91_PMC_PDIV (1 << 12) /* Processor Clock Division [some SAM9 only] */
#define AT91_PMC_PDIV_1 (0 << 12)
#define AT91_PMC_PDIV_2 (1 << 12)
#define AT91_PMC_PLLADIV2 (1 << 12) /* PLLA divisor by 2 [some SAM9 only] */
#define AT91_PMC_PLLADIV2_OFF (0 << 12)
#define AT91_PMC_PLLADIV2_ON (1 << 12)

#define AT91_PMC_PCKR(n) (AT91_PMC + 0x40 + ((n) * 4)) /* Programmable Clock 0-3 Registers */
#define AT91_PMC_USB (AT91_PMC + 0x38) /* USB Clock Register [some SAM9 only] */
#define AT91_PMC_USBS (0x1 << 0) /* USB OHCI Input clock selection */
#define AT91_PMC_USBS_PLLA (0 << 0)
#define AT91_PMC_USBS_UPLL (1 << 0)
#define AT91_PMC_OHCIUSBDIV (0xF << 8) /* Divider for USB OHCI Clock */

#define AT91_PMC_PCKR(n) (AT91_PMC + 0x40 + ((n) * 4)) /* Programmable Clock 0-N Registers */
#define AT91_PMC_CSSMCK (0x1 << 8) /* CSS or Master Clock Selection */
#define AT91_PMC_CSSMCK_CSS (0 << 8)
#define AT91_PMC_CSSMCK_MCK (1 << 8)

#define AT91_PMC_IER (AT91_PMC + 0x60) /* Interrupt Enable Register */
#define AT91_PMC_IDR (AT91_PMC + 0x64) /* Interrupt Disable Register */
Expand All @@ -102,7 +116,7 @@
#define AT91_PMC_LOCKA (1 << 1) /* PLLA Lock */
#define AT91_PMC_LOCKB (1 << 2) /* PLLB Lock */
#define AT91_PMC_MCKRDY (1 << 3) /* Master Clock */
#define AT91_PMC_LOCKU (1 << 6) /* UPLL Lock [AT91CAP9 only] */
#define AT91_PMC_LOCKU (1 << 6) /* UPLL Lock [some SAM9, AT91CAP9 only] */
#define AT91_PMC_OSCSEL (1 << 7) /* Slow Clock Oscillator [AT91CAP9 revC only] */
#define AT91_PMC_PCK0RDY (1 << 8) /* Programmable Clock 0 */
#define AT91_PMC_PCK1RDY (1 << 9) /* Programmable Clock 1 */
Expand Down

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