Skip to content

Commit

Permalink
ARM: LPC32xx: USB Support
Browse files Browse the repository at this point in the history 
This patch adds OHCI support to the LPC32xx ARM platform. Besides the trivial
addition of platform "usb-ohci" support, fixes for the USB PLL have been added
to arch/arm/mach-lpc32xx/clock.c, ported from NXP's lpclinux.com.

(This is the mach-lpc32xx specific part, the USB subsystem specific changes are
in a separate patch for the USB maintainers.)

Signed-off-by: Roland Stigge <stigge@antcom.de>
  • Loading branch information
Roland Stigge committed Mar 13, 2012
1 parent a7e4c6a commit 48a5ded
Show file tree
Hide file tree
Showing 4 changed files with 91 additions and 24 deletions.
87 changes: 63 additions & 24 deletions arch/arm/mach-lpc32xx/clock.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -87,6 +87,7 @@
#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>
Expand All @@ -100,6 +101,8 @@

static DEFINE_SPINLOCK(global_clkregs_lock);

static int usb_pll_enable, usb_pll_valid;

static struct clk clk_armpll;
static struct clk clk_usbpll;

Expand Down Expand Up @@ -384,30 +387,62 @@ 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 = jiffies + 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 */
/*
* Enable PLL
*/
reg |= LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP;
__raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);

/*
* Wait for PLL to lock
*/
while (time_before(jiffies, timeout) && (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;
Expand All @@ -425,7 +460,7 @@ 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;
Expand All @@ -439,7 +474,8 @@ 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;

/*
Expand All @@ -448,7 +484,7 @@ 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;
Expand All @@ -457,22 +493,25 @@ 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 = {
Expand Down
26 changes: 26 additions & 0 deletions arch/arm/mach-lpc32xx/common.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -159,6 +159,32 @@ struct platform_device lpc32xx_adc_device = {
.resource = adc_resources,
};

/*
* USB support
*/
/* The dmamask must be set for OHCI to work */
static u64 ohci_dmamask = ~(u32) 0;
static struct resource ohci_resources[] = {
{
.start = IO_ADDRESS(LPC32XX_USB_BASE),
.end = IO_ADDRESS(LPC32XX_USB_BASE + 0x100 - 1),
.flags = IORESOURCE_MEM,
}, {
.start = IRQ_LPC32XX_USB_HOST,
.flags = IORESOURCE_IRQ,
},
};
struct platform_device lpc32xx_ohci_device = {
.name = "usb-ohci",
.id = -1,
.dev = {
.dma_mask = &ohci_dmamask,
.coherent_dma_mask = 0xFFFFFFFF,
},
.num_resources = ARRAY_SIZE(ohci_resources),
.resource = ohci_resources,
};

/*
* Returns the unique ID for the device
*/
Expand Down
1 change: 1 addition & 0 deletions arch/arm/mach-lpc32xx/common.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@ extern struct platform_device lpc32xx_i2c2_device;
extern struct platform_device lpc32xx_tsc_device;
extern struct platform_device lpc32xx_adc_device;
extern struct platform_device lpc32xx_rtc_device;
extern struct platform_device lpc32xx_ohci_device;

/*
* Other arch specific structures and functions
Expand Down
1 change: 1 addition & 0 deletions arch/arm/mach-lpc32xx/phy3250.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -279,6 +279,7 @@ static struct platform_device *phy3250_devs[] __initdata = {
&lpc32xx_watchdog_device,
&lpc32xx_gpio_led_device,
&lpc32xx_adc_device,
&lpc32xx_ohci_device,
};

static struct amba_device *amba_devs[] __initdata = {
Expand Down

0 comments on commit 48a5ded

Please sign in to comment.