[U-Boot] [PATCH v6 5/5] usb: lpc32xx: add host USB driver

Vladimir Zapolskiy vz at mleia.com
Wed Aug 12 19:55:29 CEST 2015


Hi Sylvain,

On 10.08.2015 15:16, slemieux.tyco at gmail.com wrote:
> From: Sylvain Lemieux <slemieux at tycoint.com>
> 
> Incorporate USB driver from legacy LPCLinux NXP BSP.
> The files taken from the legacy patch are:
> - lpc32xx USB driver
> - lpc3250 header file USB registers definition.
> 
> The legacy driver was updated and clean-up as part of the integration with the latest u-boot.
> 
> Signed-off-by: Sylvain Lemieux <slemieux at tycoint.com>
> ---
> Changes from v5 to v6:
> * Addressed Marek's comments on LPC32xx USB driver: 
>   - return "-ETIMEDOUT" on timeout. 
> * Addressed Vladimir's comments on LPC32xx USB driver:
>   - follow alphabetic order when adding "lpc32xx_usb_init()".
>   - use "CONFIG_SYS_HZ" when verifying if timer expired.
>   - use "wait_for_bit()" when verify the I2C OTG clock status.
> 
> Changes from v4 to v5:
> * Addressed Marek's comments on LPC32xx USB driver:
>   - update "wait_for_bit()" implementation to use "get_timer()".
>   - use return value of "wait_for_bit()" instead of
>     returning -1.
> * Updated multiline comments style.
> 
> Changes from v3 to v4:
> * Addressed Marek's comments on LPC32xx USB driver:
>   - use same "wait_for_bit()" implementation as
>     drivers/usb/host/dwc2.c
>   - use a const variable to define a mask to make
>     the code more clear to read.
> * Fixed legacy USB driver; use "otg_clk_sts" register
>   to verify clock status instead of control register.
> 
> Changes from v2 to v3:
> * Addressed Marek's comments on LPC32xx USB driver:
>   - use "get_timer()" to handle timeout (usbpll_setup).
>   - submit i2c driver update into a separate patch.
>   - use "u32" for 4 bytes registers definition.
>   - Move pin mux code to setup file (i.e. "device.c").
> * Updated ISP1301 register definition (set & clear) instead 
>   of using an extra mask for the clear address.
> 
> Changes from v1 to v2:
> * Addressed Marek's comments on LPC32xx USB driver:
>   - use "get_timer()" to handle timeout.
>   - Split USB and I2C driver.
> * Updated LPC32xx I2C driver to support the I2C that is part
>   of the USB module.
> * Removed ISP1301 USB transceiver I2C registers definition
>   that are not used.
> * Use "cpu" initialization & stop functions API instead of the "board" API.
> 
> Update to the legacy driver to integrate with the latest u-boot:
> 1) Fixed checkpatch script output in legacy code.
> 2) Use LPC32xx definition from "cpu.h" and "clk.h".
> 3) Incorporate USB specific register definition from "lpc3250.h"
>    header file from legacy BSP patch from LPCLinux.
> 4) Use u-boot API for register access to remove the volatile
>    in register definition taken from "lpc3250.h" header file.
> 5) Update driver for latest u-boot USB API.
> 6) Use the peripheral clock to compute the I2C divider.
> 
> The legacy BSP patch (u-boot-2009.03_lpc32x0-v1.07.patch.tar.bz2)
> was downloaded from the LPCLinux Web site.
> 
>  arch/arm/cpu/arm926ejs/lpc32xx/devices.c      |   6 +
>  arch/arm/include/asm/arch-lpc32xx/clk.h       |  12 ++
>  arch/arm/include/asm/arch-lpc32xx/sys_proto.h |   1 +
>  drivers/usb/host/Makefile                     |   1 +
>  drivers/usb/host/ohci-lpc32xx.c               | 235 ++++++++++++++++++++++++++
>  5 files changed, 255 insertions(+)
>  create mode 100644 drivers/usb/host/ohci-lpc32xx.c
> 


With best wishes,
Vladimir

> diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> index f0af851..d9fa280 100644
> --- a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> +++ b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> @@ -72,6 +72,12 @@ void lpc32xx_slc_nand_init(void)
>  	writel(CLK_NAND_SLC | CLK_NAND_SLC_SELECT, &clk->flashclk_ctrl);
>  }
>  
> +void lpc32xx_usb_init(void)
> +{
> +	/* Do not route the UART 5 Tx/Rx pins to the USB D+ and USB D- pins. */
> +	clrbits_le32(&ctrl->ctrl, UART_CTRL_UART5_USB_MODE);
> +}
> +
>  void lpc32xx_i2c_init(unsigned int devnum)
>  {
>  	/* Enable I2C interface */
> diff --git a/arch/arm/include/asm/arch-lpc32xx/clk.h b/arch/arm/include/asm/arch-lpc32xx/clk.h
> index 663f6bc..d21310e 100644
> --- a/arch/arm/include/asm/arch-lpc32xx/clk.h
> +++ b/arch/arm/include/asm/arch-lpc32xx/clk.h
> @@ -167,6 +167,18 @@ struct clk_pm_regs {
>  /* SDRAMCLK register bits */
>  #define CLK_SDRAM_DDR_SEL		(1 << 1)
>  
> +/* USB control register definitions */
> +#define CLK_USBCTRL_PLL_STS		(1 << 0)
> +#define CLK_USBCTRL_FDBK_PLUS1(n)	(((n) & 0xFF) << 1)
> +#define CLK_USBCTRL_POSTDIV_2POW(n)	(((n) & 0x3) << 11)
> +#define CLK_USBCTRL_PLL_PWRUP		(1 << 16)
> +#define CLK_USBCTRL_CLK_EN1		(1 << 17)
> +#define CLK_USBCTRL_CLK_EN2		(1 << 18)
> +#define CLK_USBCTRL_BUS_KEEPER		(0x1 << 19)
> +#define CLK_USBCTRL_USBHSTND_EN		(1 << 21)
> +#define CLK_USBCTRL_USBDVND_EN		(1 << 22)
> +#define CLK_USBCTRL_HCLK_EN		(1 << 24)
> +
>  unsigned int get_sys_clk_rate(void);
>  unsigned int get_hclk_pll_rate(void);
>  unsigned int get_hclk_clk_div(void);
> diff --git a/arch/arm/include/asm/arch-lpc32xx/sys_proto.h b/arch/arm/include/asm/arch-lpc32xx/sys_proto.h
> index d6e5e68..eb8010f 100644
> --- a/arch/arm/include/asm/arch-lpc32xx/sys_proto.h
> +++ b/arch/arm/include/asm/arch-lpc32xx/sys_proto.h
> @@ -16,6 +16,7 @@ void lpc32xx_mlc_nand_init(void);
>  void lpc32xx_slc_nand_init(void);
>  void lpc32xx_i2c_init(unsigned int devnum);
>  void lpc32xx_ssp_init(void);
> +void lpc32xx_usb_init(void);
>  #if defined(CONFIG_SPL_BUILD)
>  void ddr_init(const struct emc_dram_settings *dram);
>  #endif
> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> index 4d35d3e..9dfdc94 100644
> --- a/drivers/usb/host/Makefile
> +++ b/drivers/usb/host/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_USB_SL811HS) += sl811-hcd.o
>  obj-$(CONFIG_USB_OHCI_S3C24XX) += ohci-s3c24xx.o
>  obj-$(CONFIG_USB_OHCI_EP93XX) += ohci-ep93xx.o
>  obj-$(CONFIG_USB_OHCI_SUNXI) += ohci-sunxi.o
> +obj-$(CONFIG_USB_OHCI_LPC32XX) += ohci-lpc32xx.o
>  
>  # echi
>  obj-$(CONFIG_USB_EHCI) += ehci-hcd.o
> diff --git a/drivers/usb/host/ohci-lpc32xx.c b/drivers/usb/host/ohci-lpc32xx.c
> new file mode 100644
> index 0000000..acf356b
> --- /dev/null
> +++ b/drivers/usb/host/ohci-lpc32xx.c
> @@ -0,0 +1,235 @@
> +/*
> + * Copyright (C) 2008 by NXP Semiconductors
> + * @Author: Based on code by Kevin Wells
> + * @Descr: USB driver - Embedded Artists LPC3250 OEM Board support functions
> + *
> + * Copyright (c) 2015 Tyco Fire Protection Products.
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <errno.h>
> +#include <asm/io.h>
> +#include <asm/arch/cpu.h>
> +#include <asm/arch/clk.h>
> +#include <usb.h>
> +#include <i2c.h>
> +
> +/* OTG I2C controller module register structures */
> +struct otgi2c_regs {
> +	u32 otg_i2c_txrx;   /* OTG I2C Tx/Rx Data FIFO */
> +	u32 otg_i2c_stat;   /* OTG I2C Status Register */
> +	u32 otg_i2c_ctrl;   /* OTG I2C Control Register */
> +	u32 otg_i2c_clk_hi; /* OTG I2C Clock Divider high */
> +	u32 otg_i2c_clk_lo; /* OTG I2C Clock Divider low */
> +};
> +
> +/* OTG controller module register structures */
> +struct otg_regs {
> +	u32 reserved1[64];
> +	u32 otg_int_sts;    /* OTG int status register */
> +	u32 otg_int_enab;   /* OTG int enable register */
> +	u32 otg_int_set;    /* OTG int set register */
> +	u32 otg_int_clr;    /* OTG int clear register */
> +	u32 otg_sts_ctrl;   /* OTG status/control register */
> +	u32 otg_timer;      /* OTG timer register */
> +	u32 reserved2[122];
> +	struct otgi2c_regs otg_i2c;
> +	u32 reserved3[824];
> +	u32 otg_clk_ctrl;   /* OTG clock control reg */
> +	u32 otg_clk_sts;    /* OTG clock status reg */
> +};
> +
> +/* otg_sts_ctrl register definitions */
> +#define OTG_HOST_EN			(1 << 0) /* Enable host mode */
> +
> +/* otg_clk_ctrl and otg_clk_sts register definitions */
> +#define OTG_CLK_AHB_EN			(1 << 4) /* Enable AHB clock */
> +#define OTG_CLK_OTG_EN			(1 << 3) /* Enable OTG clock */
> +#define OTG_CLK_I2C_EN			(1 << 2) /* Enable I2C clock */
> +#define OTG_CLK_HOST_EN			(1 << 0) /* Enable host clock */
> +
> +/* ISP1301 USB transceiver I2C registers */
> +#define MC1_SPEED_REG			(1 << 0)
> +#define MC1_DAT_SE0			(1 << 2)
> +#define MC1_UART_EN			(1 << 6)
> +
> +#define MC2_SPD_SUSP_CTRL		(1 << 1)
> +#define MC2_BI_DI			(1 << 2)
> +#define MC2_PSW_EN			(1 << 6)
> +
> +#define OTG1_DP_PULLUP			(1 << 0)
> +#define OTG1_DM_PULLUP			(1 << 1)
> +#define OTG1_DP_PULLDOWN		(1 << 2)
> +#define OTG1_DM_PULLDOWN		(1 << 3)
> +#define OTG1_VBUS_DRV			(1 << 5)
> +
> +#define ISP1301_I2C_ADDR		CONFIG_USB_ISP1301_I2C_ADDR
> +
> +#define ISP1301_I2C_MODE_CONTROL_1_SET		0x04
> +#define ISP1301_I2C_MODE_CONTROL_1_CLR		0x05
> +#define ISP1301_I2C_MODE_CONTROL_2_SET		0x12
> +#define ISP1301_I2C_MODE_CONTROL_2_CLR		0x13
> +#define ISP1301_I2C_OTG_CONTROL_1_SET		0x06
> +#define ISP1301_I2C_OTG_CONTROL_1_CLR		0x07
> +#define ISP1301_I2C_INTERRUPT_LATCH_CLR		0x0B
> +#define ISP1301_I2C_INTERRUPT_FALLING_CLR	0x0D
> +#define ISP1301_I2C_INTERRUPT_RISING_CLR	0x0F
> +
> +static struct otg_regs *otg = (struct otg_regs *)USB_BASE;
> +static struct clk_pm_regs *clk_pwr = (struct clk_pm_regs *)CLK_PM_BASE;
> +
> +static int wait_for_bit(void *reg, const u32 mask, bool set)
> +{

(set == false) argument is not in use, and hence there is a piece of
dead code in the function.

> +	u32 val;
> +	unsigned long start = get_timer(0);
> +
> +	while (1) {
> +		val = readl(reg);
> +		if (!set)
> +			val = ~val;
> +
> +		if ((val & mask) == mask)
> +			return 0;
> +
> +		if (get_timer(start) > CONFIG_SYS_HZ)
> +			break;
> +
> +		udelay(1);
> +	}
> +
> +	debug("%s: Timeout (reg=%p mask=%08x wait_set=%i)\n",
> +	      __func__, reg, mask, set);

I would recommend on error path always to display this message to a user.

> +	return -ETIMEDOUT;
> +}
> +
> +static int isp1301_set_value(int reg, u8 value)
> +{
> +	return i2c_write(ISP1301_I2C_ADDR, reg, 1, &value, 1);
> +}
> +
> +static void isp1301_configure(void)
> +{
> +	i2c_set_bus_num(I2C_2);
> +
> +	/*
> +	 * LPC32XX only supports DAT_SE0 USB mode
> +	 * This sequence is important
> +	 */
> +
> +	/* Disable transparent UART mode first */
> +	isp1301_set_value(ISP1301_I2C_MODE_CONTROL_1_CLR, MC1_UART_EN);
> +
> +	isp1301_set_value(ISP1301_I2C_MODE_CONTROL_1_CLR, ~MC1_SPEED_REG);
> +	isp1301_set_value(ISP1301_I2C_MODE_CONTROL_1_SET, MC1_SPEED_REG);
> +	isp1301_set_value(ISP1301_I2C_MODE_CONTROL_2_CLR, ~0);
> +	isp1301_set_value(ISP1301_I2C_MODE_CONTROL_2_SET,
> +			  MC2_BI_DI | MC2_PSW_EN | MC2_SPD_SUSP_CTRL);
> +
> +	isp1301_set_value(ISP1301_I2C_OTG_CONTROL_1_CLR, ~0);
> +	isp1301_set_value(ISP1301_I2C_MODE_CONTROL_1_SET, MC1_DAT_SE0);
> +	isp1301_set_value(ISP1301_I2C_OTG_CONTROL_1_SET,
> +			  OTG1_DM_PULLDOWN | OTG1_DP_PULLDOWN);
> +	isp1301_set_value(ISP1301_I2C_OTG_CONTROL_1_CLR,
> +			  OTG1_DM_PULLUP | OTG1_DP_PULLUP);
> +	isp1301_set_value(ISP1301_I2C_INTERRUPT_LATCH_CLR, ~0);
> +	isp1301_set_value(ISP1301_I2C_INTERRUPT_FALLING_CLR, ~0);
> +	isp1301_set_value(ISP1301_I2C_INTERRUPT_RISING_CLR, ~0);
> +
> +	/* Enable usb_need_clk clock after transceiver is initialized */
> +	setbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_USBDVND_EN);
> +}
> +
> +static int usbpll_setup(void)
> +{
> +	u32 ret;
> +
> +	/* make sure clocks are disabled */
> +	clrbits_le32(&clk_pwr->usb_ctrl,
> +		     CLK_USBCTRL_CLK_EN1 | CLK_USBCTRL_CLK_EN2);
> +
> +	/* start PLL clock input */
> +	setbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_CLK_EN1);
> +
> +	/* Setup PLL. */
> +	setbits_le32(&clk_pwr->usb_ctrl,
> +		     CLK_USBCTRL_FDBK_PLUS1(192 - 1));
> +	setbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_POSTDIV_2POW(0x01));
> +	setbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_PLL_PWRUP);
> +
> +	ret = wait_for_bit(&clk_pwr->usb_ctrl, CLK_USBCTRL_PLL_STS, 1);
> +	if (ret)
> +		return ret;
> +
> +	/* enable PLL output */
> +	setbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_CLK_EN2);
> +
> +	return 0;
> +}
> +
> +int usb_cpu_init(void)
> +{
> +	u32 ret;
> +
> +	/*
> +	 * USB pins routing setup is done by "lpc32xx_usb_init()" and should
> +	 * be call by board "board_init()" or "misc_init_r()" functions.
> +	 */
> +
> +	/* enable AHB slave USB clock */
> +	setbits_le32(&clk_pwr->usb_ctrl,
> +		     CLK_USBCTRL_HCLK_EN | CLK_USBCTRL_BUS_KEEPER);
> +
> +	/* enable I2C clock in OTG block if it isn't */
> +	if ((readl(&otg->otg_clk_sts) & OTG_CLK_I2C_EN) != OTG_CLK_I2C_EN) {

if (!(readl(&otg->otg_clk_sts) & OTG_CLK_I2C_EN))

> +		writel(OTG_CLK_I2C_EN, &otg->otg_clk_ctrl);
> +
> +		ret = wait_for_bit(&otg->otg_clk_sts, OTG_CLK_I2C_EN, 1);
> +		if (ret)
> +			return ret;

Or actually the embracing check may be dropped and
writel(OTG_CLK_I2C_EN) / wait_for_bit() are done unconditionally.

> +	}
> +
> +	/* Configure ISP1301 */
> +	isp1301_configure();

Not sure if there are any LPC32xx boards with USB host/device, but
without ISP1301 phy. Let it be here until such a board emerges, if Marek
does not object.

In general I wonder, won't drivers/usb/phy/ be a better place for this
driver or bigger part of it?

> +
> +	/* setup USB clocks and PLL */
> +	ret = usbpll_setup();
> +	if (ret)
> +		return ret;
> +
> +	/* enable usb_host_need_clk */
> +	setbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_USBHSTND_EN);
> +
> +	/* enable all needed USB clocks */
> +	const u32 mask = OTG_CLK_AHB_EN | OTG_CLK_OTG_EN |
> +			 OTG_CLK_I2C_EN | OTG_CLK_HOST_EN;
> +	writel(mask, &otg->otg_clk_ctrl);
> +
> +	ret = wait_for_bit(&otg->otg_clk_sts, mask, 1);
> +	if (ret)
> +		return ret;
> +
> +	setbits_le32(&otg->otg_sts_ctrl, OTG_HOST_EN);
> +	isp1301_set_value(ISP1301_I2C_OTG_CONTROL_1_SET, OTG1_VBUS_DRV);
> +
> +	return 0;
> +}
> +
> +int usb_cpu_stop(void)
> +{
> +	/* vbus off */
> +	isp1301_set_value(ISP1301_I2C_OTG_CONTROL_1_SET, OTG1_VBUS_DRV);
> +
> +	clrbits_le32(&otg->otg_sts_ctrl, OTG_HOST_EN);
> +
> +	clrbits_le32(&clk_pwr->usb_ctrl, CLK_USBCTRL_HCLK_EN);
> +
> +	return 0;
> +}
> +
> +int usb_cpu_init_fail(void)
> +{
> +	return usb_cpu_stop();
> +}
> 

Feel free to add my

Tested-by: Vladimir Zapolskiy <vz at mleia.com>

--
With best wishes,
Vladimir


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