[ARM] 5438/1: AT91: manage clock by functionality instead of CPUs

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>

1 files changed, 112 insertions, 39 deletions

diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
index e4345106ee57..bac578fe0d3d 100644
--- a/arch/arm/mach-at91/clock.c
+++ b/arch/arm/mach-at91/clock.c
@@ -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);
 
@@ -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,
 };
 
@@ -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;
@@ -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;
@@ -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;
@@ -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");
@@ -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;
@@ -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.
@@ -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" */