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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2010, 2011 Cavium Networks
*/
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-uctlx-defs.h>
static DEFINE_MUTEX(octeon2_usb_clocks_mutex);
static int octeon2_usb_clock_start_cnt;
void octeon2_usb_clocks_start(void)
{
u64 div;
union cvmx_uctlx_if_ena if_ena;
union cvmx_uctlx_clk_rst_ctl clk_rst_ctl;
union cvmx_uctlx_uphy_ctl_status uphy_ctl_status;
union cvmx_uctlx_uphy_portx_ctl_status port_ctl_status;
int i;
unsigned long io_clk_64_to_ns;
mutex_lock(&octeon2_usb_clocks_mutex);
octeon2_usb_clock_start_cnt++;
if (octeon2_usb_clock_start_cnt != 1)
goto exit;
io_clk_64_to_ns = 64000000000ull / octeon_get_io_clock_rate();
/*
* Step 1: Wait for voltages stable. That surely happened
* before starting the kernel.
*
* Step 2: Enable SCLK of UCTL by writing UCTL0_IF_ENA[EN] = 1
*/
if_ena.u64 = 0;
if_ena.s.en = 1;
cvmx_write_csr(CVMX_UCTLX_IF_ENA(0), if_ena.u64);
/* Step 3: Configure the reference clock, PHY, and HCLK */
clk_rst_ctl.u64 = cvmx_read_csr(CVMX_UCTLX_CLK_RST_CTL(0));
/*
* If the UCTL looks like it has already been started, skip
* the initialization, otherwise bus errors are obtained.
*/
if (clk_rst_ctl.s.hrst)
goto end_clock;
/* 3a */
clk_rst_ctl.s.p_por = 1;
clk_rst_ctl.s.hrst = 0;
clk_rst_ctl.s.p_prst = 0;
clk_rst_ctl.s.h_clkdiv_rst = 0;
clk_rst_ctl.s.o_clkdiv_rst = 0;
clk_rst_ctl.s.h_clkdiv_en = 0;
clk_rst_ctl.s.o_clkdiv_en = 0;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* 3b */
/* 12MHz crystal. */
clk_rst_ctl.s.p_refclk_sel = 0;
clk_rst_ctl.s.p_refclk_div = 0;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* 3c */
div = octeon_get_io_clock_rate() / 130000000ull;
switch (div) {
case 0:
div = 1;
break;
case 1:
case 2:
case 3:
case 4:
break;
case 5:
div = 4;
break;
case 6:
case 7:
div = 6;
break;
case 8:
case 9:
case 10:
case 11:
div = 8;
break;
default:
div = 12;
break;
}
clk_rst_ctl.s.h_div = div;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* Read it back, */
clk_rst_ctl.u64 = cvmx_read_csr(CVMX_UCTLX_CLK_RST_CTL(0));
clk_rst_ctl.s.h_clkdiv_en = 1;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* 3d */
clk_rst_ctl.s.h_clkdiv_rst = 1;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* 3e: delay 64 io clocks */
ndelay(io_clk_64_to_ns);
/*
* Step 4: Program the power-on reset field in the UCTL
* clock-reset-control register.
*/
clk_rst_ctl.s.p_por = 0;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* Step 5: Wait 1 ms for the PHY clock to start. */
mdelay(1);
/*
* Step 6: Program the reset input from automatic test
* equipment field in the UPHY CSR
*/
uphy_ctl_status.u64 = cvmx_read_csr(CVMX_UCTLX_UPHY_CTL_STATUS(0));
uphy_ctl_status.s.ate_reset = 1;
cvmx_write_csr(CVMX_UCTLX_UPHY_CTL_STATUS(0), uphy_ctl_status.u64);
/* Step 7: Wait for at least 10ns. */
ndelay(10);
/* Step 8: Clear the ATE_RESET field in the UPHY CSR. */
uphy_ctl_status.s.ate_reset = 0;
cvmx_write_csr(CVMX_UCTLX_UPHY_CTL_STATUS(0), uphy_ctl_status.u64);
/*
* Step 9: Wait for at least 20ns for UPHY to output PHY clock
* signals and OHCI_CLK48
*/
ndelay(20);
/* Step 10: Configure the OHCI_CLK48 and OHCI_CLK12 clocks. */
/* 10a */
clk_rst_ctl.s.o_clkdiv_rst = 1;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* 10b */
clk_rst_ctl.s.o_clkdiv_en = 1;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* 10c */
ndelay(io_clk_64_to_ns);
/*
* Step 11: Program the PHY reset field:
* UCTL0_CLK_RST_CTL[P_PRST] = 1
*/
clk_rst_ctl.s.p_prst = 1;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
/* Step 12: Wait 1 uS. */
udelay(1);
/* Step 13: Program the HRESET_N field: UCTL0_CLK_RST_CTL[HRST] = 1 */
clk_rst_ctl.s.hrst = 1;
cvmx_write_csr(CVMX_UCTLX_CLK_RST_CTL(0), clk_rst_ctl.u64);
end_clock:
/* Now we can set some other registers. */
for (i = 0; i <= 1; i++) {
port_ctl_status.u64 =
cvmx_read_csr(CVMX_UCTLX_UPHY_PORTX_CTL_STATUS(i, 0));
/* Set txvreftune to 15 to obtain compliant 'eye' diagram. */
port_ctl_status.s.txvreftune = 15;
port_ctl_status.s.txrisetune = 1;
port_ctl_status.s.txpreemphasistune = 1;
cvmx_write_csr(CVMX_UCTLX_UPHY_PORTX_CTL_STATUS(i, 0),
port_ctl_status.u64);
}
exit:
mutex_unlock(&octeon2_usb_clocks_mutex);
}
EXPORT_SYMBOL(octeon2_usb_clocks_start);
void octeon2_usb_clocks_stop(void)
{
mutex_lock(&octeon2_usb_clocks_mutex);
octeon2_usb_clock_start_cnt--;
mutex_unlock(&octeon2_usb_clocks_mutex);
}
EXPORT_SYMBOL(octeon2_usb_clocks_stop);
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