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authorVille Syrjala <syrjala@sci.fi>2008-03-04 14:28:50 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-03-04 16:35:13 -0800
commit3149be50d3a31df095bcc83d752293da65a37f62 (patch)
treea40c9c16c47cbfe40bc2c16d1352ebccab5cc769 /drivers/mfd
parent245904a4ce08c48495b2fd6d6c317c26ddf2b57a (diff)
sm501: add support for the SM502 programmable PLL
SM502 has a programmable PLL which can provide the panel pixel clock instead of the 288MHz and 336MHz PLLs. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Ville Syrjala <syrjala@sci.fi> Cc: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/sm501.c163
1 files changed, 128 insertions, 35 deletions
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index 4de8d467762..13bac53db69 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -48,6 +48,7 @@ struct sm501_devdata {
unsigned int pdev_id;
unsigned int irq;
void __iomem *regs;
+ unsigned int rev;
};
#define MHZ (1000 * 1000)
@@ -417,46 +418,108 @@ struct sm501_clock {
unsigned long mclk;
int divider;
int shift;
+ unsigned int m, n, k;
};
+/* sm501_calc_clock
+ *
+ * Calculates the nearest discrete clock frequency that
+ * can be achieved with the specified input clock.
+ * the maximum divisor is 3 or 5
+ */
+
+static int sm501_calc_clock(unsigned long freq,
+ struct sm501_clock *clock,
+ int max_div,
+ unsigned long mclk,
+ long *best_diff)
+{
+ int ret = 0;
+ int divider;
+ int shift;
+ long diff;
+
+ /* try dividers 1 and 3 for CRT and for panel,
+ try divider 5 for panel only.*/
+
+ for (divider = 1; divider <= max_div; divider += 2) {
+ /* try all 8 shift values.*/
+ for (shift = 0; shift < 8; shift++) {
+ /* Calculate difference to requested clock */
+ diff = sm501fb_round_div(mclk, divider << shift) - freq;
+ if (diff < 0)
+ diff = -diff;
+
+ /* If it is less than the current, use it */
+ if (diff < *best_diff) {
+ *best_diff = diff;
+
+ clock->mclk = mclk;
+ clock->divider = divider;
+ clock->shift = shift;
+ ret = 1;
+ }
+ }
+ }
+
+ return ret;
+}
+
+/* sm501_calc_pll
+ *
+ * Calculates the nearest discrete clock frequency that can be
+ * achieved using the programmable PLL.
+ * the maximum divisor is 3 or 5
+ */
+
+static unsigned long sm501_calc_pll(unsigned long freq,
+ struct sm501_clock *clock,
+ int max_div)
+{
+ unsigned long mclk;
+ unsigned int m, n, k;
+ long best_diff = 999999999;
+
+ /*
+ * The SM502 datasheet doesn't specify the min/max values for M and N.
+ * N = 1 at least doesn't work in practice.
+ */
+ for (m = 2; m <= 255; m++) {
+ for (n = 2; n <= 127; n++) {
+ for (k = 0; k <= 1; k++) {
+ mclk = (24000000UL * m / n) >> k;
+
+ if (sm501_calc_clock(freq, clock, max_div,
+ mclk, &best_diff)) {
+ clock->m = m;
+ clock->n = n;
+ clock->k = k;
+ }
+ }
+ }
+ }
+
+ /* Return best clock. */
+ return clock->mclk / (clock->divider << clock->shift);
+}
+
/* sm501_select_clock
*
- * selects nearest discrete clock frequency the SM501 can achive
+ * Calculates the nearest discrete clock frequency that can be
+ * achieved using the 288MHz and 336MHz PLLs.
* the maximum divisor is 3 or 5
*/
+
static unsigned long sm501_select_clock(unsigned long freq,
struct sm501_clock *clock,
int max_div)
{
unsigned long mclk;
- int divider;
- int shift;
- long diff;
long best_diff = 999999999;
/* Try 288MHz and 336MHz clocks. */
for (mclk = 288000000; mclk <= 336000000; mclk += 48000000) {
- /* try dividers 1 and 3 for CRT and for panel,
- try divider 5 for panel only.*/
-
- for (divider = 1; divider <= max_div; divider += 2) {
- /* try all 8 shift values.*/
- for (shift = 0; shift < 8; shift++) {
- /* Calculate difference to requested clock */
- diff = sm501fb_round_div(mclk, divider << shift) - freq;
- if (diff < 0)
- diff = -diff;
-
- /* If it is less than the current, use it */
- if (diff < best_diff) {
- best_diff = diff;
-
- clock->mclk = mclk;
- clock->divider = divider;
- clock->shift = shift;
- }
- }
- }
+ sm501_calc_clock(freq, clock, max_div, mclk, &best_diff);
}
/* Return best clock. */
@@ -478,6 +541,7 @@ unsigned long sm501_set_clock(struct device *dev,
unsigned long gate = readl(sm->regs + SM501_CURRENT_GATE);
unsigned long clock = readl(sm->regs + SM501_CURRENT_CLOCK);
unsigned char reg;
+ unsigned int pll_reg = 0;
unsigned long sm501_freq; /* the actual frequency acheived */
struct sm501_clock to;
@@ -492,14 +556,28 @@ unsigned long sm501_set_clock(struct device *dev,
* requested frequency the value must be multiplied by
* 2. This clock also has an additional pre divisor */
- sm501_freq = (sm501_select_clock(2 * req_freq, &to, 5) / 2);
- reg=to.shift & 0x07;/* bottom 3 bits are shift */
- if (to.divider == 3)
- reg |= 0x08; /* /3 divider required */
- else if (to.divider == 5)
- reg |= 0x10; /* /5 divider required */
- if (to.mclk != 288000000)
- reg |= 0x20; /* which mclk pll is source */
+ if (sm->rev >= 0xC0) {
+ /* SM502 -> use the programmable PLL */
+ sm501_freq = (sm501_calc_pll(2 * req_freq,
+ &to, 5) / 2);
+ reg = to.shift & 0x07;/* bottom 3 bits are shift */
+ if (to.divider == 3)
+ reg |= 0x08; /* /3 divider required */
+ else if (to.divider == 5)
+ reg |= 0x10; /* /5 divider required */
+ reg |= 0x40; /* select the programmable PLL */
+ pll_reg = 0x20000 | (to.k << 15) | (to.n << 8) | to.m;
+ } else {
+ sm501_freq = (sm501_select_clock(2 * req_freq,
+ &to, 5) / 2);
+ reg = to.shift & 0x07;/* bottom 3 bits are shift */
+ if (to.divider == 3)
+ reg |= 0x08; /* /3 divider required */
+ else if (to.divider == 5)
+ reg |= 0x10; /* /5 divider required */
+ if (to.mclk != 288000000)
+ reg |= 0x20; /* which mclk pll is source */
+ }
break;
case SM501_CLOCK_V2XCLK:
@@ -560,6 +638,10 @@ unsigned long sm501_set_clock(struct device *dev,
}
writel(mode, sm->regs + SM501_POWER_MODE_CONTROL);
+
+ if (pll_reg)
+ writel(pll_reg, sm->regs + SM501_PROGRAMMABLE_PLL_CONTROL);
+
sm501_sync_regs(sm);
dev_info(sm->dev, "gate %08lx, clock %08lx, mode %08lx\n",
@@ -580,15 +662,24 @@ EXPORT_SYMBOL_GPL(sm501_set_clock);
* finds the closest available frequency for a given clock
*/
-unsigned long sm501_find_clock(int clksrc,
+unsigned long sm501_find_clock(struct device *dev,
+ int clksrc,
unsigned long req_freq)
{
+ struct sm501_devdata *sm = dev_get_drvdata(dev);
unsigned long sm501_freq; /* the frequency achiveable by the 501 */
struct sm501_clock to;
switch (clksrc) {
case SM501_CLOCK_P2XCLK:
- sm501_freq = (sm501_select_clock(2 * req_freq, &to, 5) / 2);
+ if (sm->rev >= 0xC0) {
+ /* SM502 -> use the programmable PLL */
+ sm501_freq = (sm501_calc_pll(2 * req_freq,
+ &to, 5) / 2);
+ } else {
+ sm501_freq = (sm501_select_clock(2 * req_freq,
+ &to, 5) / 2);
+ }
break;
case SM501_CLOCK_V2XCLK:
@@ -895,6 +986,8 @@ static int sm501_init_dev(struct sm501_devdata *sm)
dev_info(sm->dev, "SM501 At %p: Version %08lx, %ld Mb, IRQ %d\n",
sm->regs, devid, (unsigned long)mem_avail >> 20, sm->irq);
+ sm->rev = devid & SM501_DEVICEID_REVMASK;
+
sm501_dump_gate(sm);
ret = device_create_file(sm->dev, &dev_attr_dbg_regs);