* [PATCH v4] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP
@ 2016-04-27 11:51 Prabu Thangamuthu
2016-04-27 13:39 ` Andy Shevchenko
0 siblings, 1 reply; 4+ messages in thread
From: Prabu Thangamuthu @ 2016-04-27 11:51 UTC (permalink / raw)
To: Ulf Hansson (ulf.hansson@linaro.org),
Adrian Hunter, Bjorn Helgaas, Andrew Morton, David S. Miller,
Greg Kroah-Hartman, Kalle Valo, Mauro Carvalho Chehab,
Guenter Roeck, Jiri Slaby, Chaotian Jing, Andrei Pistirica,
Ben Hutchings, Joshua Henderson, Ludovic Desroches
Cc: prabu.t, Manjunath M Bettegowda, linux-mmc, linux-kernel
Patch for Standard SD Host Controller Interface compliant Synopsys
sdhci-dwc controller driver. This code supports PCI based interface.
Signed-off-by: Prabu Thangamuthu <prabu.t@synopsys.com>
---
Change log v4:
-Updated review comments to optimize the code.
Change log v3:
-Removed unused code.
-Updated review comments.
Change log v2:
-Removed Synopsys specific PCI device ID's from pci_ids.h.
-Updated the PCI device ID's in sdhci-pci-core.c.
MAINTAINERS | 7 ++
drivers/mmc/host/Makefile | 3 +-
drivers/mmc/host/sdhci-pci-core.c | 14 +++
drivers/mmc/host/sdhci-pci-dwc.c | 244 ++++++++++++++++++++++++++++++++++++++
drivers/mmc/host/sdhci-pci-dwc.h | 55 +++++++++
5 files changed, 322 insertions(+), 1 deletion(-)
create mode 100644 drivers/mmc/host/sdhci-pci-dwc.c
create mode 100644 drivers/mmc/host/sdhci-pci-dwc.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 8491336..c98bdb1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9751,6 +9751,13 @@ S: Maintained
F: include/linux/mmc/dw_mmc.h
F: drivers/mmc/host/dw_mmc*
+SYNOPSYS SDHCI COMPLIANT DWC MSHC DRIVER
+M: Prabu Thangamuthu <prabu.t@synopsys.com>
+M: Manjunath M B <manjumb@synopsys.com>
+L: linux-mmc@vger.kernel.org
+S: Maintained
+F: drivers/mmc/host/sdhci-pci-dwc*
+
SYSTEM TRACE MODULE CLASS
M: Alexander Shishkin <alexander.shishkin@linux.intel.com>
S: Maintained
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index af918d2..092a746 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -9,7 +9,8 @@ obj-$(CONFIG_MMC_MXC) += mxcmmc.o
obj-$(CONFIG_MMC_MXS) += mxs-mmc.o
obj-$(CONFIG_MMC_SDHCI) += sdhci.o
obj-$(CONFIG_MMC_SDHCI_PCI) += sdhci-pci.o
-sdhci-pci-y += sdhci-pci-core.o sdhci-pci-o2micro.o
+sdhci-pci-y += sdhci-pci-core.o sdhci-pci-o2micro.o \
+ sdhci-pci-dwc.o
obj-$(subst m,y,$(CONFIG_MMC_SDHCI_PCI)) += sdhci-pci-data.o
obj-$(CONFIG_MMC_SDHCI_ACPI) += sdhci-acpi.o
obj-$(CONFIG_MMC_SDHCI_PXAV3) += sdhci-pxav3.o
diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index 79e1901..4a7769c 100644
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -31,6 +31,7 @@
#include "sdhci.h"
#include "sdhci-pci.h"
#include "sdhci-pci-o2micro.h"
+#include "sdhci-pci-dwc.h"
/*****************************************************************************\
* *
@@ -70,6 +71,11 @@ static int ricoh_mmc_resume(struct sdhci_pci_chip *chip)
msleep(500);
return 0;
}
+/* Synopsys SDHCI compliant Controller */
+static const struct sdhci_pci_fixes sdhci_snps = {
+ .probe_slot = sdhci_pci_probe_slot_snps,
+ .quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
+};
static const struct sdhci_pci_fixes sdhci_ricoh = {
.probe = ricoh_probe,
@@ -797,6 +803,14 @@ static const struct sdhci_pci_fixes sdhci_amd = {
static const struct pci_device_id pci_ids[] = {
{
+ .vendor = PCI_VENDOR_ID_SYNOPSYS,
+ .device = 0xc201, /* Device ID of sdhci-dwc on Haps51 */
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .driver_data = (kernel_ulong_t)&sdhci_snps,
+ },
+
+ {
.vendor = PCI_VENDOR_ID_RICOH,
.device = PCI_DEVICE_ID_RICOH_R5C822,
.subvendor = PCI_ANY_ID,
diff --git a/drivers/mmc/host/sdhci-pci-dwc.c b/drivers/mmc/host/sdhci-pci-dwc.c
new file mode 100644
index 0000000..3a2fcac
--- /dev/null
+++ b/drivers/mmc/host/sdhci-pci-dwc.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2016 Synopsys, Inc.
+ *
+ * Author: Manjunath M B <manjumb@synopsys.com>
+ * Prabu Thangamuthu <prabu.t@synopsys.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+#include "sdhci.h"
+#include "sdhci-pci.h"
+#include "sdhci-pci-dwc.h"
+
+/*****************************************************************************\
+ * *
+ * Hardware specific clock handling *
+ * *
+\*****************************************************************************/
+
+static void snps_reset_dcm(struct sdhci_host *host, u32 mask, u8 reset)
+{
+ u16 vendor_ptr;
+ u32 reg;
+
+ vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
+
+ reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
+
+ if (reset == 1)
+ reg |= mask;
+ else
+ reg &= ~mask;
+
+ sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
+}
+
+static void sdhci_set_clock_snps(struct sdhci_host *host, u32 clock)
+{
+ u8 div;
+ u8 mul;
+ u8 div_val;
+ u8 mul_val;
+ u8 timeout;
+ u16 clk;
+ u16 vendor_ptr;
+ u16 mul_div_val;
+ u32 reg;
+
+ /*
+ * if clock is less than 25MHz, divided clock is used.
+ * For divided clock, we can use the standard sdhci_set_clock().
+ * For clock above 25MHz, DRP clock is used
+ * Here, we cannot use sdhci_set_clock(), we need to program
+ * TX RX CLOCK DCM DRP for appropriate clock
+ */
+
+ if (clock <= 25000000) {
+ /* Then call standard set_clock */
+ sdhci_set_clock(host, clock);
+ } else {
+
+ host->mmc->actual_clock = 0;
+ vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
+
+ /* Select un-phase shifted clock before reset Tx Tuning DCM*/
+ reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
+ reg &= ~SDHC_TX_CLK_SEL_TUNED;
+ sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
+ mdelay(10);
+
+ sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
+
+ /* Lets chose the Mulitplier value to be 0x2 */
+ mul = 0x2;
+ for (div = 1; div <= 32; div++) {
+ if (((host->max_clk * mul) / div)
+ <= clock)
+ break;
+ }
+ /*
+ * Set Programmable Clock Mode in the Clock
+ * Control register.
+ */
+ div_val = div - 1;
+ mul_val = mul - 1;
+
+ host->mmc->actual_clock = (host->max_clk * mul) / div;
+ /*
+ * Program the DCM DRP
+ * Step 1: Assert DCM Reset
+ * Step 2: Program the mul and div values in DRP
+ * Step 3: Read from DRP base 0x00 to restore DCM output as per
+ * www.xilinx.com/support/documentation/user_guides/ug191.pdf
+ * Step 4: De-Assert reset to DCM
+ */
+
+ snps_reset_dcm(host, SDHC_CARD_TX_CLK_DCM_RST, 1);
+
+ mul_div_val = (mul_val << 8) | div_val;
+ sdhci_writew(host, mul_div_val, TXRX_CLK_DCM_MUL_DIV_DRP);
+ sdhci_readl(host, TXRX_CLK_DCM_DRP_BASE_51);
+
+ snps_reset_dcm(host, SDHC_CARD_TX_CLK_DCM_RST, 0);
+
+ clk = SDHCI_PROG_CLOCK_MODE | SDHCI_CLOCK_INT_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+ /* Wait max 20 ms */
+ timeout = 20;
+ while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
+ & SDHCI_CLOCK_INT_STABLE)) {
+ if (timeout == 0) {
+ pr_err("%s: Internal clock never stabilised\n",
+ mmc_hostname(host->mmc));
+ return;
+ }
+ timeout--;
+ mdelay(1);
+ }
+
+ clk |= SDHCI_CLOCK_CARD_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+ /*
+ * This Clock might have affected the TX CLOCK DCM and RX CLOCK
+ * DCM which are used for Phase control; Reset these DCM's
+ * for proper clock output
+ *
+ * Step 1: Reset the DCM
+ * Step 2: De-Assert reset to DCM
+ */
+
+ snps_reset_dcm(host, SDHC_TUNING_TX_CLK_DCM_RST |
+ SDHC_TUNING_RX_CLK_DCM_RST, 1);
+ mdelay(10);
+ snps_reset_dcm(host, SDHC_TUNING_TX_CLK_DCM_RST |
+ SDHC_TUNING_RX_CLK_DCM_RST, 0);
+
+ /* Select working phase value if clock is <= 50MHz */
+ if (clock <= 50000000) {
+ /*Change the Tx Phase value here */
+ reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
+ reg |= (SDHC_TUNING_TX_CLK_SEL_MASK &
+ (SDHC_DEF_TX_CLK_PH_VAL <<
+ SDHC_TUNING_TX_CLK_SEL_SHIFT));
+
+ sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
+ mdelay(10);
+
+ /* Program to select phase shifted clock */
+ reg |= SDHC_TX_CLK_SEL_TUNED;
+ sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
+
+ /*
+ * For 50Mhz, tuning is not possible.
+ * Lets fix the sampling Phase of Rx Clock here.
+ */
+ reg = sdhci_readl(host, (SDHC_DBOUNCE + vendor_ptr));
+ reg &= ~SDHC_TUNING_RX_CLK_SEL_MASK;
+ reg |= (SDHC_TUNING_RX_CLK_SEL_MASK &
+ SDHC_DEF_RX_CLK_PH_VAL);
+ sdhci_writel(host, reg, (SDHC_DBOUNCE + vendor_ptr));
+ }
+ mdelay(10);
+ }
+}
+
+static int snps_init_clock(struct sdhci_host *host)
+{
+ u16 mul_div_val;
+
+ /*
+ * Configure the BCLK DRP to get 100 MHZ Clock
+ * To get 100MHz from 100MHz input freq,
+ * mul=1 and div=1
+ * Formula: output_clock = (input clock * mul) / div
+ *
+ * Program the DCM DRP
+ * Step 1: Assert DCM Reset
+ * Step 2: Program the mul and div values in DRP
+ * Step 3: Read from DRP base 0x00 to restore DCM output as per
+ * www.xilinx.com/support/documentation/user_guides/ug191.pdf
+ * Step 4: De-Assert reset to DCM
+ */
+ snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 1);
+
+ mul_div_val = 0x0101;
+ sdhci_writew(host, mul_div_val, BCLK_DCM_MUL_DIV_DRP);
+ sdhci_readl(host, BCLK_DCM_DRP_BASE_51);
+
+ snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 0);
+
+ /*
+ * By Default Clocks to Controller are OFF.
+ * Before stack applies reset; we need to turn on the clock
+ */
+ sdhci_writew(host, SDHCI_CLOCK_INT_EN, SDHCI_CLOCK_CONTROL);
+
+ return 0;
+
+}
+static struct sdhci_ops sdhci_pci_ops_snps = {
+ .set_clock = sdhci_set_clock_snps,
+};
+
+int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot)
+{
+ int ret = 0;
+ struct sdhci_host *host;
+ const struct sdhci_ops *sdhci_pci_ops; /* Low level hw interface */
+
+ host = slot->host;
+ sdhci_pci_ops = host->ops;
+
+ sdhci_pci_ops_snps.enable_dma = sdhci_pci_ops->enable_dma;
+ sdhci_pci_ops_snps.set_bus_width = sdhci_pci_ops->set_bus_width;
+ sdhci_pci_ops_snps.reset = sdhci_pci_ops->reset;
+ sdhci_pci_ops_snps.set_uhs_signaling =
+ sdhci_pci_ops->set_uhs_signaling;
+ sdhci_pci_ops_snps.hw_reset = sdhci_pci_ops->hw_reset;
+ sdhci_pci_ops_snps.select_drive_strength =
+ sdhci_pci_ops->select_drive_strength;
+
+ host->ops = &sdhci_pci_ops_snps;
+
+ /* Board specific clock initialization */
+ ret = snps_init_clock(host);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(sdhci_pci_probe_slot_snps);
diff --git a/drivers/mmc/host/sdhci-pci-dwc.h b/drivers/mmc/host/sdhci-pci-dwc.h
new file mode 100644
index 0000000..02e2213
--- /dev/null
+++ b/drivers/mmc/host/sdhci-pci-dwc.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2016 Synopsys, Inc.
+ *
+ * Author: Manjunath M B <manjumb@synopsys.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __SDHCI_DWC_MSHC_PCI_H__
+#define __SDHCI_DWC_MSHC_PCI_H__
+
+#include "sdhci-pci.h"
+
+#define SDHCI_UHS2_VENDOR 0xE8
+
+#define DRIVER_NAME "sdhci-pci-dwc"
+#define SDHC_DEF_TX_CLK_PH_VAL 4
+#define SDHC_DEF_RX_CLK_PH_VAL 4
+
+/* Synopsys Vendor Specific Registers */
+#define SDHC_DBOUNCE 0x08
+#define SDHC_TUNING_RX_CLK_SEL_MASK 0x000000FF
+#define SDHC_GPIO_OUT 0x34
+/* HAPS 51 Based implementation */
+#define SDHC_BCLK_DCM_RST 0x00000001
+#define SDHC_CARD_TX_CLK_DCM_RST 0x00000002
+#define SDHC_TUNING_RX_CLK_DCM_RST 0x00000004
+#define SDHC_TUNING_TX_CLK_DCM_RST 0x00000008
+#define SDHC_TUNING_TX_CLK_SEL_MASK 0x00000070
+#define SDHC_TUNING_TX_CLK_SEL_SHIFT 4
+#define SDHC_TX_CLK_SEL_TUNED 0x00000080
+
+/* Offset of BCLK DCM DRP Attributes */
+/* Every attribute is of 16 bit wide */
+#define BCLK_DCM_DRP_BASE_51 0x1000
+
+#define BCLK_DCM_MUL_DIV_DRP 0x1050
+#define MUL_MASK_DRP 0xFF00
+#define DIV_MASK_DRP 0x00FF
+
+/* Offset of TX and RX CLK DCM DRP */
+#define TXRX_CLK_DCM_DRP_BASE_51 0x2000
+#define TXRX_CLK_DCM_MUL_DIV_DRP 0x2050
+
+int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot);
+
+#endif
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v4] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP
2016-04-27 11:51 [PATCH v4] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP Prabu Thangamuthu
@ 2016-04-27 13:39 ` Andy Shevchenko
2016-04-28 8:35 ` Prabu Thangamuthu
0 siblings, 1 reply; 4+ messages in thread
From: Andy Shevchenko @ 2016-04-27 13:39 UTC (permalink / raw)
To: Prabu Thangamuthu
Cc: Ulf Hansson (ulf.hansson@linaro.org),
Adrian Hunter, Bjorn Helgaas, Andrew Morton, David S. Miller,
Greg Kroah-Hartman, Kalle Valo, Mauro Carvalho Chehab,
Guenter Roeck, Jiri Slaby, Chaotian Jing, Andrei Pistirica,
Ben Hutchings, Joshua Henderson, Ludovic Desroches,
Manjunath M Bettegowda, linux-mmc, linux-kernel
On Wed, Apr 27, 2016 at 2:51 PM, Prabu Thangamuthu <Prabu.T@synopsys.com> wrote:
> Patch for Standard SD Host Controller Interface compliant Synopsys
> sdhci-dwc controller driver. This code supports PCI based interface.
> @@ -0,0 +1,244 @@
> +/*
> + * Copyright (C) 2016 Synopsys, Inc.
> + *
> + * Author: Manjunath M B <manjumb@synopsys.com>
Authors
> + * Prabu Thangamuthu <prabu.t@synopsys.com>
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +/*****************************************************************************\
> + * *
> + * Hardware specific clock handling *
> + * *
> +\*****************************************************************************/
Most of the lines are non-informative.
> +static void snps_reset_dcm(struct sdhci_host *host, u32 mask, u8 reset)
> +{
> + u16 vendor_ptr;
> + u32 reg;
> +
> + vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
> +
> + reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
> +
> + if (reset == 1)
> + reg |= mask;
> + else
> + reg &= ~mask;
> +
> + sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
> +}
> +
> +static void sdhci_set_clock_snps(struct sdhci_host *host, u32 clock)
> +{
> + u8 div;
> + u8 mul;
I understand that CodingStyle recommends to keep one variable by line,
but here might be useful to combine related variables
u8 mul, div;
> + u8 div_val;
> + u8 mul_val;
u8 mul_val, div_val;
Up to you and to maintainers.
> + u8 timeout;
> + u16 clk;
> + u16 vendor_ptr;
> + u16 mul_div_val;
> + u32 reg;
> +
> + /*
> + * if clock is less than 25MHz, divided clock is used.
if -> If
> + * For divided clock, we can use the standard sdhci_set_clock().
> + * For clock above 25MHz, DRP clock is used
Dot.
> + * Here, we cannot use sdhci_set_clock(), we need to program
> + * TX RX CLOCK DCM DRP for appropriate clock
Ditto.
> + */
> +
Redundant.
> + if (clock <= 25000000) {
> + /* Then call standard set_clock */
> + sdhci_set_clock(host, clock);
> + } else {
You may save indentation if you return directly in positive branch.
> +
> + host->mmc->actual_clock = 0;
> + vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
> +
> + /* Select un-phase shifted clock before reset Tx Tuning DCM*/
Space is missed
> + reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
> + reg &= ~SDHC_TX_CLK_SEL_TUNED;
> + sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
> + mdelay(10);
Why?! Explanation is needed.
> +
> + sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> +
> + /* Lets chose the Mulitplier value to be 0x2 */
Lets -> Let's
No explanation why so?
> + mul = 0x2;
> + for (div = 1; div <= 32; div++) {
> + if (((host->max_clk * mul) / div)
> + <= clock)
Too many parens.
> + break;
> + }
So, you would like to find a minimum divider that guarantees the
clock > max_clk * mul / div.
This is completely long way to achieve.
What about
div = DIV_ROUND_UP(max_clk * mul / clock)
div_val = max(div, 32);
> + /*
> + * Set Programmable Clock Mode in the Clock
> + * Control register.
> + */
I suppose one line after fixing indentation.
> + div_val = div - 1;
> + mul_val = mul - 1;
> +
> + host->mmc->actual_clock = (host->max_clk * mul) / div;
> + /*
> + * Program the DCM DRP
> + * Step 1: Assert DCM Reset
> + * Step 2: Program the mul and div values in DRP
> + * Step 3: Read from DRP base 0x00 to restore DCM output as per
> + * www.xilinx.com/support/documentation/user_guides/ug191.pdf
> + * Step 4: De-Assert reset to DCM
> + */
> +
> + snps_reset_dcm(host, SDHC_CARD_TX_CLK_DCM_RST, 1);
> +
> + mul_div_val = (mul_val << 8) | div_val;
> + sdhci_writew(host, mul_div_val, TXRX_CLK_DCM_MUL_DIV_DRP);
> + sdhci_readl(host, TXRX_CLK_DCM_DRP_BASE_51);
> +
> + snps_reset_dcm(host, SDHC_CARD_TX_CLK_DCM_RST, 0);
> +
> + clk = SDHCI_PROG_CLOCK_MODE | SDHCI_CLOCK_INT_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + /* Wait max 20 ms */
> + timeout = 20;
> + while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> + & SDHCI_CLOCK_INT_STABLE)) {
> + if (timeout == 0) {
This is invariant to the loop. Check how it's done in other drivers.
Something like
while (condition && --timeout) {
...
}
if (!timeout) {
...
}
> + pr_err("%s: Internal clock never stabilised\n",
> + mmc_hostname(host->mmc));
dev_err() ?
> + return;
> + }
> + timeout--;
> + mdelay(1);
> + }
> +
> + clk |= SDHCI_CLOCK_CARD_EN;
> + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> + /*
> + * This Clock might have affected the TX CLOCK DCM and RX CLOCK
> + * DCM which are used for Phase control; Reset these DCM's
> + * for proper clock output
> + *
> + * Step 1: Reset the DCM
> + * Step 2: De-Assert reset to DCM
> + */
> +
> + snps_reset_dcm(host, SDHC_TUNING_TX_CLK_DCM_RST |
> + SDHC_TUNING_RX_CLK_DCM_RST, 1);
> + mdelay(10);
> + snps_reset_dcm(host, SDHC_TUNING_TX_CLK_DCM_RST |
> + SDHC_TUNING_RX_CLK_DCM_RST, 0);
> +
> + /* Select working phase value if clock is <= 50MHz */
> + if (clock <= 50000000) {
> + /*Change the Tx Phase value here */
Space
> + reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
> + reg |= (SDHC_TUNING_TX_CLK_SEL_MASK &
> + (SDHC_DEF_TX_CLK_PH_VAL <<
> + SDHC_TUNING_TX_CLK_SEL_SHIFT));
> +
> + sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
> + mdelay(10);
Why?!
> +
> + /* Program to select phase shifted clock */
> + reg |= SDHC_TX_CLK_SEL_TUNED;
> + sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
> +
> + /*
> + * For 50Mhz, tuning is not possible.
> + * Lets fix the sampling Phase of Rx Clock here.
> + */
> + reg = sdhci_readl(host, (SDHC_DBOUNCE + vendor_ptr));
> + reg &= ~SDHC_TUNING_RX_CLK_SEL_MASK;
> + reg |= (SDHC_TUNING_RX_CLK_SEL_MASK &
> + SDHC_DEF_RX_CLK_PH_VAL);
> + sdhci_writel(host, reg, (SDHC_DBOUNCE + vendor_ptr));
> + }
> + mdelay(10);
Ditto.
> + }
> +}
Don't have time to go further. Check your code fully and carefully.
> +
> +static int snps_init_clock(struct sdhci_host *host)
> +{
> + u16 mul_div_val;
> +
> + /*
> + * Configure the BCLK DRP to get 100 MHZ Clock
> + * To get 100MHz from 100MHz input freq,
> + * mul=1 and div=1
> + * Formula: output_clock = (input clock * mul) / div
> + *
> + * Program the DCM DRP
> + * Step 1: Assert DCM Reset
> + * Step 2: Program the mul and div values in DRP
> + * Step 3: Read from DRP base 0x00 to restore DCM output as per
> + * www.xilinx.com/support/documentation/user_guides/ug191.pdf
> + * Step 4: De-Assert reset to DCM
> + */
> + snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 1);
> +
> + mul_div_val = 0x0101;
> + sdhci_writew(host, mul_div_val, BCLK_DCM_MUL_DIV_DRP);
> + sdhci_readl(host, BCLK_DCM_DRP_BASE_51);
> +
> + snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 0);
> +
> + /*
> + * By Default Clocks to Controller are OFF.
> + * Before stack applies reset; we need to turn on the clock
> + */
> + sdhci_writew(host, SDHCI_CLOCK_INT_EN, SDHCI_CLOCK_CONTROL);
> +
> + return 0;
> +
> +}
> +static struct sdhci_ops sdhci_pci_ops_snps = {
> + .set_clock = sdhci_set_clock_snps,
> +};
> +
> +int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot)
> +{
> + int ret = 0;
> + struct sdhci_host *host;
> + const struct sdhci_ops *sdhci_pci_ops; /* Low level hw interface */
> +
> + host = slot->host;
> + sdhci_pci_ops = host->ops;
> +
> + sdhci_pci_ops_snps.enable_dma = sdhci_pci_ops->enable_dma;
> + sdhci_pci_ops_snps.set_bus_width = sdhci_pci_ops->set_bus_width;
> + sdhci_pci_ops_snps.reset = sdhci_pci_ops->reset;
> + sdhci_pci_ops_snps.set_uhs_signaling =
> + sdhci_pci_ops->set_uhs_signaling;
> + sdhci_pci_ops_snps.hw_reset = sdhci_pci_ops->hw_reset;
> + sdhci_pci_ops_snps.select_drive_strength =
> + sdhci_pci_ops->select_drive_strength;
> +
> + host->ops = &sdhci_pci_ops_snps;
> +
> + /* Board specific clock initialization */
> + ret = snps_init_clock(host);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(sdhci_pci_probe_slot_snps);
> diff --git a/drivers/mmc/host/sdhci-pci-dwc.h b/drivers/mmc/host/sdhci-pci-dwc.h
> new file mode 100644
> index 0000000..02e2213
> --- /dev/null
> +++ b/drivers/mmc/host/sdhci-pci-dwc.h
> @@ -0,0 +1,55 @@
> +/*
> + * Copyright (C) 2016 Synopsys, Inc.
> + *
> + * Author: Manjunath M B <manjumb@synopsys.com>
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#ifndef __SDHCI_DWC_MSHC_PCI_H__
> +#define __SDHCI_DWC_MSHC_PCI_H__
> +
> +#include "sdhci-pci.h"
> +
> +#define SDHCI_UHS2_VENDOR 0xE8
> +
> +#define DRIVER_NAME "sdhci-pci-dwc"
> +#define SDHC_DEF_TX_CLK_PH_VAL 4
> +#define SDHC_DEF_RX_CLK_PH_VAL 4
> +
> +/* Synopsys Vendor Specific Registers */
> +#define SDHC_DBOUNCE 0x08
> +#define SDHC_TUNING_RX_CLK_SEL_MASK 0x000000FF
> +#define SDHC_GPIO_OUT 0x34
> +/* HAPS 51 Based implementation */
> +#define SDHC_BCLK_DCM_RST 0x00000001
> +#define SDHC_CARD_TX_CLK_DCM_RST 0x00000002
> +#define SDHC_TUNING_RX_CLK_DCM_RST 0x00000004
> +#define SDHC_TUNING_TX_CLK_DCM_RST 0x00000008
> +#define SDHC_TUNING_TX_CLK_SEL_MASK 0x00000070
> +#define SDHC_TUNING_TX_CLK_SEL_SHIFT 4
> +#define SDHC_TX_CLK_SEL_TUNED 0x00000080
> +
> +/* Offset of BCLK DCM DRP Attributes */
> +/* Every attribute is of 16 bit wide */
> +#define BCLK_DCM_DRP_BASE_51 0x1000
> +
> +#define BCLK_DCM_MUL_DIV_DRP 0x1050
> +#define MUL_MASK_DRP 0xFF00
> +#define DIV_MASK_DRP 0x00FF
> +
> +/* Offset of TX and RX CLK DCM DRP */
> +#define TXRX_CLK_DCM_DRP_BASE_51 0x2000
> +#define TXRX_CLK_DCM_MUL_DIV_DRP 0x2050
> +
> +int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot);
> +
> +#endif
> --
> 1.9.1
>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 4+ messages in thread* RE: [PATCH v4] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP
2016-04-27 13:39 ` Andy Shevchenko
@ 2016-04-28 8:35 ` Prabu Thangamuthu
2016-04-28 9:19 ` Andy Shevchenko
0 siblings, 1 reply; 4+ messages in thread
From: Prabu Thangamuthu @ 2016-04-28 8:35 UTC (permalink / raw)
To: Andy Shevchenko, Prabu Thangamuthu
Cc: Ulf Hansson (ulf.hansson@linaro.org),
Adrian Hunter, Bjorn Helgaas, Andrew Morton, David S. Miller,
Greg Kroah-Hartman, Kalle Valo, Mauro Carvalho Chehab,
Guenter Roeck, Jiri Slaby, Chaotian Jing, Andrei Pistirica,
Ben Hutchings, Joshua Henderson, Ludovic Desroches,
Manjunath M Bettegowda, linux-mmc, linux-kernel
Hi Andy Shevchenko,
On 04/27/2016 7:09 PM, Andy Shevchenko wrote:
>
> On Wed, Apr 27, 2016 at 2:51 PM, Prabu Thangamuthu
> <Prabu.T@synopsys.com> wrote:
> > Patch for Standard SD Host Controller Interface compliant Synopsys
> > sdhci-dwc controller driver. This code supports PCI based interface.
>
> > @@ -0,0 +1,244 @@
> > +/*
> > + * Copyright (C) 2016 Synopsys, Inc.
> > + *
> > + * Author: Manjunath M B <manjumb@synopsys.com>
>
> Authors
>
> > + * Prabu Thangamuthu <prabu.t@synopsys.com>
> > + *
> > + * This software is licensed under the terms of the GNU General
> > + Public
> > + * License version 2, as published by the Free Software Foundation,
> > + and
> > + * may be copied, distributed, and modified under those terms.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + *
> > + */
>
>
> >
> +/*********************************************************
> ********************\
> > + * *
> > + * Hardware specific clock handling *
> > + * *
> >
> +\*********************************************************
> ***********
> > +*********/
>
> Most of the lines are non-informative.
>
> > +static void snps_reset_dcm(struct sdhci_host *host, u32 mask, u8
> > +reset) {
> > + u16 vendor_ptr;
> > + u32 reg;
> > +
> > + vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
> > +
> > + reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
> > +
> > + if (reset == 1)
> > + reg |= mask;
> > + else
> > + reg &= ~mask;
> > +
> > + sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr)); }
> > +
> > +static void sdhci_set_clock_snps(struct sdhci_host *host, u32 clock)
> > +{
> > + u8 div;
> > + u8 mul;
>
> I understand that CodingStyle recommends to keep one variable by line, but
> here might be useful to combine related variables
>
> u8 mul, div;
>
> > + u8 div_val;
> > + u8 mul_val;
>
> u8 mul_val, div_val;
>
> Up to you and to maintainers.
>
> > + u8 timeout;
> > + u16 clk;
> > + u16 vendor_ptr;
> > + u16 mul_div_val;
> > + u32 reg;
> > +
> > + /*
> > + * if clock is less than 25MHz, divided clock is used.
>
> if -> If
>
> > + * For divided clock, we can use the standard sdhci_set_clock().
> > + * For clock above 25MHz, DRP clock is used
>
> Dot.
>
> > + * Here, we cannot use sdhci_set_clock(), we need to program
> > + * TX RX CLOCK DCM DRP for appropriate clock
>
> Ditto.
>
> > + */
>
> > +
>
> Redundant.
>
> > + if (clock <= 25000000) {
> > + /* Then call standard set_clock */
> > + sdhci_set_clock(host, clock);
>
> > + } else {
>
> You may save indentation if you return directly in positive branch.
> > +
> > + host->mmc->actual_clock = 0;
> > + vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
> > +
> > + /* Select un-phase shifted clock before reset Tx
> > + Tuning DCM*/
>
> Space is missed
>
> > + reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
> > + reg &= ~SDHC_TX_CLK_SEL_TUNED;
> > + sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
>
> > + mdelay(10);
>
> Why?! Explanation is needed.
>
> > +
> > + sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> > +
> > + /* Lets chose the Mulitplier value to be 0x2 */
>
> Lets -> Let's
>
> No explanation why so?
>
> > + mul = 0x2;
> > + for (div = 1; div <= 32; div++) {
> > + if (((host->max_clk * mul) / div)
> > + <= clock)
>
> Too many parens.
>
> > + break;
> > + }
>
> So, you would like to find a minimum divider that guarantees the clock >
> max_clk * mul / div.
>
> This is completely long way to achieve.
This for loop is exactly taken from drivers/mmc/host/sdhci.c
We want to maintain the consistency between our file and sdhci.c
>
> What about
> div = DIV_ROUND_UP(max_clk * mul / clock)
>
> div_val = max(div, 32);
>
>
> > + /*
> > + * Set Programmable Clock Mode in the Clock
> > + * Control register.
> > + */
>
> I suppose one line after fixing indentation.
>
> > + div_val = div - 1;
> > + mul_val = mul - 1;
> > +
> > + host->mmc->actual_clock = (host->max_clk * mul) / div;
> > + /*
> > + * Program the DCM DRP
> > + * Step 1: Assert DCM Reset
> > + * Step 2: Program the mul and div values in DRP
> > + * Step 3: Read from DRP base 0x00 to restore DCM output as per
> > + *
> www.xilinx.com/support/documentation/user_guides/ug191.pdf
> > + * Step 4: De-Assert reset to DCM
> > + */
> > +
> > + snps_reset_dcm(host, SDHC_CARD_TX_CLK_DCM_RST, 1);
> > +
> > + mul_div_val = (mul_val << 8) | div_val;
> > + sdhci_writew(host, mul_div_val,
> TXRX_CLK_DCM_MUL_DIV_DRP);
> > + sdhci_readl(host, TXRX_CLK_DCM_DRP_BASE_51);
> > +
> > + snps_reset_dcm(host, SDHC_CARD_TX_CLK_DCM_RST, 0);
> > +
> > + clk = SDHCI_PROG_CLOCK_MODE | SDHCI_CLOCK_INT_EN;
> > + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> > +
> > + /* Wait max 20 ms */
> > + timeout = 20;
> > + while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> > + & SDHCI_CLOCK_INT_STABLE)) {
> > + if (timeout == 0) {
>
> This is invariant to the loop. Check how it's done in other drivers.
This while loop also exactly taken from drivers/mmc/host/sdhci.c (function name sdhci_set_clock).
We want to maintain the consistency between our file and sdhci.c for easy readability.
>
> Something like
>
> while (condition && --timeout) {
> ...
> }
> if (!timeout) {
> ...
> }
>
> > + pr_err("%s: Internal clock never stabilised\n",
> > +
> > + mmc_hostname(host->mmc));
>
> dev_err() ?
>
> > + return;
> > + }
> > + timeout--;
> > + mdelay(1);
> > + }
> > +
> > + clk |= SDHCI_CLOCK_CARD_EN;
> > + sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> > +
> > + /*
> > + * This Clock might have affected the TX CLOCK DCM and RX CLOCK
> > + * DCM which are used for Phase control; Reset these DCM's
> > + * for proper clock output
> > + *
> > + * Step 1: Reset the DCM
> > + * Step 2: De-Assert reset to DCM
> > + */
> > +
> > + snps_reset_dcm(host, SDHC_TUNING_TX_CLK_DCM_RST |
> > + SDHC_TUNING_RX_CLK_DCM_RST, 1);
> > + mdelay(10);
> > + snps_reset_dcm(host, SDHC_TUNING_TX_CLK_DCM_RST |
> > + SDHC_TUNING_RX_CLK_DCM_RST,
> > + 0);
> > +
> > + /* Select working phase value if clock is <= 50MHz */
> > + if (clock <= 50000000) {
> > + /*Change the Tx Phase value here */
>
> Space
I didn't get any warning/error when I ran scripts/checkpatch.pl against my patch.
Did you find this "Space" issue by manual check or by running any scripts?
>
> > + reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
> > + reg |= (SDHC_TUNING_TX_CLK_SEL_MASK &
> > + (SDHC_DEF_TX_CLK_PH_VAL <<
> > +
> > + SDHC_TUNING_TX_CLK_SEL_SHIFT));
> > +
> > + sdhci_writel(host, reg, (SDHC_GPIO_OUT +
> > + vendor_ptr));
>
> > + mdelay(10);
>
> Why?!
>
> > +
> > + /* Program to select phase shifted clock */
> > + reg |= SDHC_TX_CLK_SEL_TUNED;
> > + sdhci_writel(host, reg, (SDHC_GPIO_OUT +
> > + vendor_ptr));
> > +
> > + /*
> > + * For 50Mhz, tuning is not possible.
> > + * Lets fix the sampling Phase of Rx Clock here.
> > + */
> > + reg = sdhci_readl(host, (SDHC_DBOUNCE + vendor_ptr));
> > + reg &= ~SDHC_TUNING_RX_CLK_SEL_MASK;
> > + reg |= (SDHC_TUNING_RX_CLK_SEL_MASK &
> > + SDHC_DEF_RX_CLK_PH_VAL);
> > + sdhci_writel(host, reg, (SDHC_DBOUNCE + vendor_ptr));
> > + }
> > + mdelay(10);
>
> Ditto.
>
> > + }
> > +}
>
> Don't have time to go further. Check your code fully and carefully.
>
> > +
> > +static int snps_init_clock(struct sdhci_host *host) {
> > + u16 mul_div_val;
> > +
> > + /*
> > + * Configure the BCLK DRP to get 100 MHZ Clock
> > + * To get 100MHz from 100MHz input freq,
> > + * mul=1 and div=1
> > + * Formula: output_clock = (input clock * mul) / div
> > + *
> > + * Program the DCM DRP
> > + * Step 1: Assert DCM Reset
> > + * Step 2: Program the mul and div values in DRP
> > + * Step 3: Read from DRP base 0x00 to restore DCM output as per
> > + * www.xilinx.com/support/documentation/user_guides/ug191.pdf
> > + * Step 4: De-Assert reset to DCM
> > + */
> > + snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 1);
> > +
> > + mul_div_val = 0x0101;
> > + sdhci_writew(host, mul_div_val, BCLK_DCM_MUL_DIV_DRP);
> > + sdhci_readl(host, BCLK_DCM_DRP_BASE_51);
> > +
> > + snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 0);
> > +
> > + /*
> > + * By Default Clocks to Controller are OFF.
> > + * Before stack applies reset; we need to turn on the clock
> > + */
> > + sdhci_writew(host, SDHCI_CLOCK_INT_EN, SDHCI_CLOCK_CONTROL);
> > +
> > + return 0;
> > +
> > +}
> > +static struct sdhci_ops sdhci_pci_ops_snps = {
> > + .set_clock = sdhci_set_clock_snps,
> > +};
> > +
> > +int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot) {
> > + int ret = 0;
> > + struct sdhci_host *host;
> > + const struct sdhci_ops *sdhci_pci_ops; /* Low level hw
> > +interface */
> > +
> > + host = slot->host;
> > + sdhci_pci_ops = host->ops;
> > +
> > + sdhci_pci_ops_snps.enable_dma = sdhci_pci_ops->enable_dma;
> > + sdhci_pci_ops_snps.set_bus_width = sdhci_pci_ops-
> >set_bus_width;
> > + sdhci_pci_ops_snps.reset = sdhci_pci_ops->reset;
> > + sdhci_pci_ops_snps.set_uhs_signaling =
> > + sdhci_pci_ops->set_uhs_signaling;
> > + sdhci_pci_ops_snps.hw_reset = sdhci_pci_ops->hw_reset;
> > + sdhci_pci_ops_snps.select_drive_strength =
> > +
> > + sdhci_pci_ops->select_drive_strength;
> > +
> > + host->ops = &sdhci_pci_ops_snps;
> > +
> > + /* Board specific clock initialization */
> > + ret = snps_init_clock(host);
> > +
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_pci_probe_slot_snps);
> > diff --git a/drivers/mmc/host/sdhci-pci-dwc.h
> > b/drivers/mmc/host/sdhci-pci-dwc.h
> > new file mode 100644
> > index 0000000..02e2213
> > --- /dev/null
> > +++ b/drivers/mmc/host/sdhci-pci-dwc.h
> > @@ -0,0 +1,55 @@
> > +/*
> > + * Copyright (C) 2016 Synopsys, Inc.
> > + *
> > + * Author: Manjunath M B <manjumb@synopsys.com>
> > + *
> > + * This software is licensed under the terms of the GNU General
> > +Public
> > + * License version 2, as published by the Free Software Foundation,
> > +and
> > + * may be copied, distributed, and modified under those terms.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > + * GNU General Public License for more details.
> > + *
> > + */
> > +
> > +#ifndef __SDHCI_DWC_MSHC_PCI_H__
> > +#define __SDHCI_DWC_MSHC_PCI_H__
> > +
> > +#include "sdhci-pci.h"
> > +
> > +#define SDHCI_UHS2_VENDOR 0xE8
> > +
> > +#define DRIVER_NAME "sdhci-pci-dwc"
> > +#define SDHC_DEF_TX_CLK_PH_VAL 4
> > +#define SDHC_DEF_RX_CLK_PH_VAL 4
> > +
> > +/* Synopsys Vendor Specific Registers */
> > +#define SDHC_DBOUNCE 0x08
> > +#define SDHC_TUNING_RX_CLK_SEL_MASK 0x000000FF
> > +#define SDHC_GPIO_OUT 0x34
> > +/* HAPS 51 Based implementation */
> > +#define SDHC_BCLK_DCM_RST 0x00000001
> > +#define SDHC_CARD_TX_CLK_DCM_RST 0x00000002
> > +#define SDHC_TUNING_RX_CLK_DCM_RST 0x00000004
> > +#define SDHC_TUNING_TX_CLK_DCM_RST 0x00000008
> > +#define SDHC_TUNING_TX_CLK_SEL_MASK 0x00000070
> > +#define SDHC_TUNING_TX_CLK_SEL_SHIFT 4
> > +#define SDHC_TX_CLK_SEL_TUNED 0x00000080
> > +
> > +/* Offset of BCLK DCM DRP Attributes */
> > +/* Every attribute is of 16 bit wide */
> > +#define BCLK_DCM_DRP_BASE_51 0x1000
> > +
> > +#define BCLK_DCM_MUL_DIV_DRP 0x1050
> > +#define MUL_MASK_DRP 0xFF00
> > +#define DIV_MASK_DRP 0x00FF
> > +
> > +/* Offset of TX and RX CLK DCM DRP */
> > +#define TXRX_CLK_DCM_DRP_BASE_51 0x2000
> > +#define TXRX_CLK_DCM_MUL_DIV_DRP 0x2050
> > +
> > +int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot);
> > +
> > +#endif
> > --
> > 1.9.1
> >
Thanks for above points. We will update it.
Regards,
Prabu Thangamuthu.
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH v4] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP
2016-04-28 8:35 ` Prabu Thangamuthu
@ 2016-04-28 9:19 ` Andy Shevchenko
0 siblings, 0 replies; 4+ messages in thread
From: Andy Shevchenko @ 2016-04-28 9:19 UTC (permalink / raw)
To: Prabu Thangamuthu
Cc: Ulf Hansson (ulf.hansson@linaro.org),
Adrian Hunter, Bjorn Helgaas, Andrew Morton, David S. Miller,
Greg Kroah-Hartman, Kalle Valo, Mauro Carvalho Chehab,
Guenter Roeck, Jiri Slaby, Chaotian Jing, Andrei Pistirica,
Ben Hutchings, Joshua Henderson, Ludovic Desroches,
Manjunath M Bettegowda, linux-mmc, linux-kernel
On Thu, Apr 28, 2016 at 11:35 AM, Prabu Thangamuthu
<Prabu.T@synopsys.com> wrote:
>> > + mul = 0x2;
>> > + for (div = 1; div <= 32; div++) {
>> > + if (((host->max_clk * mul) / div)
>> > + <= clock)
>>
>> Too many parens.
>>
>> > + break;
>> > + }
>>
>> So, you would like to find a minimum divider that guarantees the clock >
>> max_clk * mul / div.
>>
>> This is completely long way to achieve.
>
> This for loop is exactly taken from drivers/mmc/host/sdhci.c
> We want to maintain the consistency between our file and sdhci.c
Any strong argument to do so? For now it's not an excuse, sorry.
>> What about
>> div = DIV_ROUND_UP(max_clk * mul / clock)
>>
>> div_val = max(div, 32);
>> > + timeout = 20;
>> > + while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
>> > + & SDHCI_CLOCK_INT_STABLE)) {
>> > + if (timeout == 0) {
>>
>> This is invariant to the loop. Check how it's done in other drivers.
>
> This while loop also exactly taken from drivers/mmc/host/sdhci.c (function name sdhci_set_clock).
> We want to maintain the consistency between our file and sdhci.c for easy readability.
Ditto.
>> Something like
>>
>> while (condition && --timeout) {
>> ...
>> }
>> if (!timeout) {
>> ...
>> }
>> > + if (clock <= 50000000) {
>> > + /*Change the Tx Phase value here */
>>
>> Space
>
> I didn't get any warning/error when I ran scripts/checkpatch.pl against my patch.
> Did you find this "Space" issue by manual check or by running any scripts?
I just noticed this like one above during manual review.
>> > +#define SDHCI_UHS2_VENDOR 0xE8
>> > +
>> > +#define DRIVER_NAME "sdhci-pci-dwc"
>> > +#define SDHC_DEF_TX_CLK_PH_VAL 4
>> > +#define SDHC_DEF_RX_CLK_PH_VAL 4
>> > +
>> > +/* Synopsys Vendor Specific Registers */
>> > +#define SDHC_DBOUNCE 0x08
>> > +#define SDHC_TUNING_RX_CLK_SEL_MASK 0x000000FF
GENMASK() ?
>> > +#define SDHC_GPIO_OUT 0x34
>> > +/* HAPS 51 Based implementation */
>> > +#define SDHC_BCLK_DCM_RST 0x00000001
BIT() ?
>> > +#define SDHC_CARD_TX_CLK_DCM_RST 0x00000002
>> > +#define SDHC_TUNING_RX_CLK_DCM_RST 0x00000004
>> > +#define SDHC_TUNING_TX_CLK_DCM_RST 0x00000008
Ditto.
>> > +#define SDHC_TUNING_TX_CLK_SEL_MASK 0x00000070
GENMASK() ?
>> > +#define SDHC_TUNING_TX_CLK_SEL_SHIFT 4
>> > +#define SDHC_TX_CLK_SEL_TUNED 0x00000080
>> > +
>> > +/* Offset of BCLK DCM DRP Attributes */
>> > +/* Every attribute is of 16 bit wide */
>> > +#define BCLK_DCM_DRP_BASE_51 0x1000
>> > +
>> > +#define BCLK_DCM_MUL_DIV_DRP 0x1050
>> > +#define MUL_MASK_DRP 0xFF00
>> > +#define DIV_MASK_DRP 0x00FF
Ditto.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-04-28 9:19 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-04-27 11:51 [PATCH v4] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP Prabu Thangamuthu
2016-04-27 13:39 ` Andy Shevchenko
2016-04-28 8:35 ` Prabu Thangamuthu
2016-04-28 9:19 ` Andy Shevchenko
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).