[PATCH] Fix LPC32XX's clock.c

Roland Stigge
2012-01-27T14:29:13Z

* Forward-ported LPC32XX's clock.c from git.lpclinux.com
* Added MLC NAND and ADC clock

Signed-off-by: Roland Stigge <stigge@antcom.de>

diff --git a/arch/arm/mach-lpc32xx/clock.c b/arch/arm/mach-lpc32xx/clock.c
index 1e02751..fabd587 100644
--- a/arch/arm/mach-lpc32xx/clock.c
+++ b/arch/arm/mach-lpc32xx/clock.c
@@ -82,10 +82,13 @@
* will also impact the individual peripheral rates.
*/

+#include <linux/module.h>
+#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/device.h>
+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/amba/bus.h>
@@ -97,9 +100,12 @@
#include "clock.h"
#include "common.h"

+static DEFINE_SPINLOCK(global_clkregs_lock);
+
+static int usb_pll_enable, usb_pll_valid;
+
static struct clk clk_armpll;
static struct clk clk_usbpll;
-static DEFINE_MUTEX(clkm_lock);

/*
* Post divider values for PLLs based on selected register value
@@ -127,7 +133,7 @@ static struct clk osc_32KHz = {
static int local_pll397_enable(struct clk *clk, int enable)
{
u32 reg;
- unsigned long timeout = 1 + msecs_to_jiffies(10);
+ unsigned long timeout = jiffies + msecs_to_jiffies(10);

reg = __raw_readl(LPC32XX_CLKPWR_PLL397_CTRL);

@@ -156,7 +162,7 @@ static int local_pll397_enable(struct clk *clk, int enable)
static int local_oscmain_enable(struct clk *clk, int enable)
{
u32 reg;
- unsigned long timeout = 1 + msecs_to_jiffies(10);
+ unsigned long timeout = jiffies + msecs_to_jiffies(10);

reg = __raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL);

@@ -382,30 +388,62 @@ static u32 local_clk_usbpll_setup(struct clk_pll_setup *pHCLKPllSetup)
static int local_usbpll_enable(struct clk *clk, int enable)
{
u32 reg;
- int ret = -ENODEV;
- unsigned long timeout = 1 + msecs_to_jiffies(10);
+ int ret = 0;
+ unsigned long timeout = jiffies + msecs_to_jiffies(20);

reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);

- if (enable == 0) {
- reg &= ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN1 |
- LPC32XX_CLKPWR_USBCTRL_CLK_EN2);
- __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
- } else if (reg & LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP) {
+ __raw_writel(reg & ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN2 |
+ LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP),
+ LPC32XX_CLKPWR_USB_CTRL);
+ __raw_writel(reg & ~LPC32XX_CLKPWR_USBCTRL_CLK_EN1,
+ LPC32XX_CLKPWR_USB_CTRL);
+
+ if (enable && usb_pll_valid && usb_pll_enable) {
+ ret = -ENODEV;
+ /*
+ * If the PLL rate has been previously set, then the rate
+ * in the PLL register is valid and can be enabled here.
+ * Otherwise, it needs to be enabled as part of setrate.
+ */
+
+ /*
+ * Gate clock into PLL
+ */
reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN1;
__raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);

- /* Wait for PLL lock */
- while ((timeout > jiffies) & (ret == -ENODEV)) {
+ /*
+ * Enable PLL
+ */
+ reg |= LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP;
+ __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
+
+ /*
+ * Wait for PLL to lock
+ */
+ while ((timeout > jiffies) && (ret == -ENODEV)) {
reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
if (reg & LPC32XX_CLKPWR_USBCTRL_PLL_STS)
ret = 0;
+ else
+ udelay(10);
}

+ /*
+ * Gate clock from PLL if PLL is locked
+ */
if (ret == 0) {
- reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN2;
- __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
+ __raw_writel(reg | LPC32XX_CLKPWR_USBCTRL_CLK_EN2,
+ LPC32XX_CLKPWR_USB_CTRL);
+ } else {
+ __raw_writel(reg & ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN1 |
+ LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP),
+ LPC32XX_CLKPWR_USB_CTRL);
}
+ } else if ((enable == 0) && usb_pll_valid && usb_pll_enable) {
+ usb_pll_valid = 0;
+ usb_pll_enable = 0;
}

return ret;
@@ -423,7 +461,7 @@ static unsigned long local_usbpll_round_rate(struct clk *clk,
*/
rate = rate * 1000;

- clkin = clk->parent->rate;
+ clkin = clk->get_rate(clk);
usbdiv = (__raw_readl(LPC32XX_CLKPWR_USBCLK_PDIV) &
LPC32XX_CLKPWR_USBPDIV_PLL_MASK) + 1;
clkin = clkin / usbdiv;
@@ -437,7 +475,8 @@ static unsigned long local_usbpll_round_rate(struct clk *clk,

static int local_usbpll_set_rate(struct clk *clk, unsigned long rate)
{
- u32 clkin, reg, usbdiv;
+ int ret = -ENODEV;
+ u32 clkin, usbdiv;
struct clk_pll_setup pllsetup;

/*
@@ -446,7 +485,7 @@ static int local_usbpll_set_rate(struct clk *clk, unsigned long rate)
*/
rate = rate * 1000;

- clkin = clk->get_rate(clk);
+ clkin = clk->get_rate(clk->parent);
usbdiv = (__raw_readl(LPC32XX_CLKPWR_USBCLK_PDIV) &
LPC32XX_CLKPWR_USBPDIV_PLL_MASK) + 1;
clkin = clkin / usbdiv;
@@ -455,22 +494,25 @@ static int local_usbpll_set_rate(struct clk *clk, unsigned long rate)
if (local_clk_find_pll_cfg(clkin, rate, &pllsetup) == 0)
return -EINVAL;

+ /*
+ * Disable PLL clocks during PLL change
+ */
local_usbpll_enable(clk, 0);
-
- reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
- reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN1;
- __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
-
- pllsetup.analog_on = 1;
+ pllsetup.analog_on = 0;
local_clk_usbpll_setup(&pllsetup);

- clk->rate = clk_check_pll_setup(clkin, &pllsetup);
+ /*
+ * Start USB PLL and check PLL status
+ */
+
+ usb_pll_valid = 1;
+ usb_pll_enable = 1;

- reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
- reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN2;
- __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
+ ret = local_usbpll_enable(clk, 1);
+ if (ret >= 0)
+ clk->rate = clk_check_pll_setup(clkin, &pllsetup);

- return 0;
+ return ret;
}

static struct clk clk_usbpll = {
@@ -654,6 +696,14 @@ static struct clk clk_nand = {
.get_rate = local_return_parent_rate,
};

+static struct clk clk_nand_mlc = {
+ .parent = &clk_hclk,
+ .enable = local_onoff_enable,
+ .enable_reg = LPC32XX_CLKPWR_NAND_CLK_CTRL,
+ .enable_mask = LPC32XX_CLKPWR_NANDCLK_MLCCLK_EN,
+ .get_rate = local_return_parent_rate,
+};
+
static struct clk clk_i2s0 = {
.parent = &clk_hclk,
.enable = local_onoff_enable,
@@ -719,6 +769,36 @@ static struct clk clk_tsc = {
.get_rate = local_return_parent_rate,
};

+static int adc_onoff_enable(struct clk *clk, int enable)
+{
+ u32 tmp;
+
+ /* Use PERIPH_CLOCK */
+ tmp = __raw_readl(LPC32XX_CLKPWR_ADC_CLK_CTRL_1);
+ tmp |= LPC32XX_CLKPWR_ADCCTRL1_PCLK_SEL;
+ /*
+ * Set clock divider so that we have equal to or less than
+ * 4.5MHz clock at ADC
+ */
+ tmp |= clk->get_rate(clk) / 4500000 + 1;
+ __raw_writel(tmp, LPC32XX_CLKPWR_ADC_CLK_CTRL_1);
+
+ if (enable == 0)
+ __raw_writel(0, clk->enable_reg);
+ else
+ __raw_writel(clk->enable_mask, clk->enable_reg);
+
+ return 0;
+}
+
+static struct clk clk_adc = {
+ .parent = &clk_pclk,
+ .enable = adc_onoff_enable,
+ .enable_reg = LPC32XX_CLKPWR_ADC_CLK_CTRL,
+ .enable_mask = LPC32XX_CLKPWR_ADC32CLKCTRL_CLK_EN,
+ .get_rate = local_return_parent_rate,
+};
+
static int mmc_onoff_enable(struct clk *clk, int enable)
{
u32 tmp;
@@ -730,6 +810,10 @@ static int mmc_onoff_enable(struct clk *clk, int enable)
if (enable != 0)
tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_EN;

+ /* Start clock at highest rate */
+ if (!(tmp & LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(0xF)))
+ tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(1);
+
__raw_writel(tmp, LPC32XX_CLKPWR_MS_CTRL);

return 0;
@@ -737,14 +821,9 @@ static int mmc_onoff_enable(struct clk *clk, int enable)

static unsigned long mmc_get_rate(struct clk *clk)
{
- u32 div, rate, oldclk;
+ u32 div, rate;

- /* The MMC clock must be on when accessing an MMC register */
- oldclk = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
- __raw_writel(oldclk | LPC32XX_CLKPWR_MSCARD_SDCARD_EN,
- LPC32XX_CLKPWR_MS_CTRL);
div = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
- __raw_writel(oldclk, LPC32XX_CLKPWR_MS_CTRL);

/* Get the parent clock rate */
rate = clk->parent->get_rate(clk->parent);
@@ -772,12 +851,19 @@ static unsigned long mmc_round_rate(struct clk *clk, unsigned long rate)
if (div > 0xf)
div = 0xf;

+ /*
+ * The divider is forced to 1 to keep the SD clock granularity
+ * good. Using a non-0 divider will limit the SD card clock rates
+ * the SD driver can generate. Remove it if your feeling crazy.
+ */
+ div = 1;
+
return prate / div;
}

static int mmc_set_rate(struct clk *clk, unsigned long rate)
{
- u32 oldclk, tmp;
+ u32 tmp;
unsigned long prate, div, crate = mmc_round_rate(clk, rate);

prate = clk->parent->get_rate(clk->parent);
@@ -785,19 +871,17 @@ static int mmc_set_rate(struct clk *clk, unsigned long rate)
div = prate / crate;

/* The MMC clock must be on when accessing an MMC register */
- oldclk = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
- __raw_writel(oldclk | LPC32XX_CLKPWR_MSCARD_SDCARD_EN,
- LPC32XX_CLKPWR_MS_CTRL);
tmp = __raw_readl(LPC32XX_CLKPWR_MS_CTRL) &
~LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(0xf);
tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(div);
__raw_writel(tmp, LPC32XX_CLKPWR_MS_CTRL);

- __raw_writel(oldclk, LPC32XX_CLKPWR_MS_CTRL);
-
return 0;
}

+/*
+ * This is the MMC IP clock, not the MMC CLK signal rate!
+ */
static struct clk clk_mmc = {
.parent = &clk_armpll,
.set_rate = mmc_set_rate,
@@ -891,19 +975,9 @@ static struct clk clk_lcd = {
.enable_mask = LPC32XX_CLKPWR_LCDCTRL_CLK_EN,
};

-static inline void clk_lock(void)
-{
- mutex_lock(&clkm_lock);
-}
-
-static inline void clk_unlock(void)
-{
- mutex_unlock(&clkm_lock);
-}
-
static void local_clk_disable(struct clk *clk)
{
- WARN_ON(clk->usecount == 0);
+ /* WARN_ON(clk->usecount == 0); */

/* Don't attempt to disable clock if it has no users */
if (clk->usecount > 0) {
@@ -947,10 +1021,11 @@ static int local_clk_enable(struct clk *clk)
int clk_enable(struct clk *clk)
{
int ret;
+ unsigned long flags;

- clk_lock();
+ spin_lock_irqsave(&global_clkregs_lock, flags);
ret = local_clk_enable(clk);
- clk_unlock();
+ spin_unlock_irqrestore(&global_clkregs_lock, flags);

return ret;
}
@@ -961,9 +1036,11 @@ EXPORT_SYMBOL(clk_enable);
*/
void clk_disable(struct clk *clk)
{
- clk_lock();
+ unsigned long flags;
+
+ spin_lock_irqsave(&global_clkregs_lock, flags);
local_clk_disable(clk);
- clk_unlock();
+ spin_unlock_irqrestore(&global_clkregs_lock, flags);
}
EXPORT_SYMBOL(clk_disable);

@@ -972,13 +1049,7 @@ EXPORT_SYMBOL(clk_disable);
*/
unsigned long clk_get_rate(struct clk *clk)
{
- unsigned long rate;
-
- clk_lock();
- rate = clk->get_rate(clk);
- clk_unlock();
-
- return rate;
+ return clk->get_rate(clk);
}
EXPORT_SYMBOL(clk_get_rate);

@@ -994,11 +1065,8 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
* the actual rate set as part of the peripheral dividers
* instead of high level clock control
*/
- if (clk->set_rate) {
- clk_lock();
+ if (clk->set_rate)
ret = clk->set_rate(clk, rate);
- clk_unlock();
- }

return ret;
}
@@ -1009,15 +1077,11 @@ EXPORT_SYMBOL(clk_set_rate);
*/
long clk_round_rate(struct clk *clk, unsigned long rate)
{
- clk_lock();
-
if (clk->round_rate)
rate = clk->round_rate(clk, rate);
else
rate = clk->get_rate(clk);

- clk_unlock();
-
return rate;
}
EXPORT_SYMBOL(clk_round_rate);
@@ -1075,6 +1139,8 @@ static struct clk_lookup lookups[] = {
_REGISTER_CLOCK("dev:ssp1", NULL, clk_ssp1)
_REGISTER_CLOCK("lpc32xx_keys.0", NULL, clk_kscan)
_REGISTER_CLOCK("lpc32xx-nand.0", "nand_ck", clk_nand)
+ _REGISTER_CLOCK("lpc32xx-nand-mlc.0", "nand_ck_mlc", clk_nand_mlc)
+ _REGISTER_CLOCK("lpc32xx-adc", NULL, clk_adc)
_REGISTER_CLOCK("tbd", "i2s0_ck", clk_i2s0)
_REGISTER_CLOCK("tbd", "i2s1_ck", clk_i2s1)
_REGISTER_CLOCK("ts-lpc32xx", NULL, clk_tsc)