Re: [PATCH v2 2/7] drivers: misc: Add support for the Lantiq PEF2256 framer

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Le 16/03/2023 à 13:27, Herve Codina a écrit :
> The Lantiq PEF2256 is a framer and line interface component designed to
> fulfill all required interfacing between an analog E1/T1/J1 line and the
> digital PCM system highway/H.100 bus.
> 
> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
> ---
>   drivers/misc/Kconfig    |   17 +
>   drivers/misc/Makefile   |    1 +
>   drivers/misc/pef2256.c  | 1441 +++++++++++++++++++++++++++++++++++++++
>   include/linux/pef2256.h |   36 +
>   4 files changed, 1495 insertions(+)
>   create mode 100644 drivers/misc/pef2256.c
>   create mode 100644 include/linux/pef2256.h
> 
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index 433aa4197785..f03739163c53 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -376,6 +376,23 @@ config HMC6352
>   	  This driver provides support for the Honeywell HMC6352 compass,
>   	  providing configuration and heading data via sysfs.
>   
> +config PEF2256
> +	tristate "Lantiq PEF2256 (FALC56) framer"
> +	depends on HAS_IOMEM
> +	select PINCTRL
> +	select PINMUX
> +	select GENERIC_PINCONF
> +	help
> +	  This option enables support for the Lantiq PEF2256 framer, also known
> +	  as FALC56. This framer and its line interface component is designed
> +	  to fulfill all required interfacing between analog E1/T1/J1 lines and
> +	  the digital PCM system highway.
> +
> +	  If unsure, say N.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called pef2256.
> +
>   config DS1682
>   	tristate "Dallas DS1682 Total Elapsed Time Recorder with Alarm"
>   	depends on I2C
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index 56de43943cd5..a26f044ab9dd 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -35,6 +35,7 @@ obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o
>   obj-$(CONFIG_DS1682)		+= ds1682.o
>   obj-$(CONFIG_C2PORT)		+= c2port/
>   obj-$(CONFIG_HMC6352)		+= hmc6352.o
> +obj-$(CONFIG_PEF2256)		+= pef2256.o
>   obj-y				+= eeprom/
>   obj-y				+= cb710/
>   obj-$(CONFIG_VMWARE_BALLOON)	+= vmw_balloon.o
> diff --git a/drivers/misc/pef2256.c b/drivers/misc/pef2256.c
> new file mode 100644
> index 000000000000..b21586084408
> --- /dev/null
> +++ b/drivers/misc/pef2256.c
> @@ -0,0 +1,1441 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * PEF2256 also known as FALC56 driver
> + *
> + * Copyright 2023 CS GROUP France
> + *
> + * Author: Herve Codina <herve.codina@xxxxxxxxxxx>
> + */
> +
> +#include <linux/pef2256.h>
> +#include <linux/clk.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/notifier.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/pinctrl/pinctrl.h>
> +#include <linux/pinctrl/pinconf-generic.h>
> +#include <linux/pinctrl/pinmux.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +#define PEF2256_CMDR		0x02 /* Command Register */
> +#define   PEF2256_CMDR_RRES	  BIT(6)
> +#define   PEF2256_CMDR_XRES	  BIT(4)
> +#define   PEF2256_CMDR_SRES	  BIT(0)
> +#define PEF2256_IMR0	        0x14 /* Interrupt Mask Register 0 */
> +#define PEF2256_IMR1	        0x15 /* Interrupt Mask Register 1 */
> +#define PEF2256_IMR2	        0x16 /* Interrupt Mask Register 2 */
> +#define PEF2256_IMR3	        0x17 /* Interrupt Mask Register 3 */
> +#define PEF2256_IMR4	        0x18 /* Interrupt Mask Register 4 */
> +#define PEF2256_IMR5	        0x19 /* Interrupt Mask Register 5 */
> +#define PEF2256_FMR0	        0x1C /* Framer Mode Register 0 */
> +#define   PEF2256_FMR0_XC_MASK	  (0x3 << 6)
> +#define     PEF2256_FMR0_XC_NRZ	    (0x0 << 6)
> +#define     PEF2256_FMR0_XC_CMI	    (0x1 << 6)
> +#define     PEF2256_FMR0_XC_AMI	    (0x2 << 6)
> +#define     PEF2256_FMR0_XC_HDB3    (0x3 << 6)
> +#define   PEF2256_FMR0_RC_MASK	  (0x3 << 4)
> +#define     PEF2256_FMR0_RC_NRZ	    (0x0 << 4)
> +#define     PEF2256_FMR0_RC_CMI	    (0x1 << 4)
> +#define     PEF2256_FMR0_RC_AMI	    (0x2 << 4)
> +#define     PEF2256_FMR0_RC_HDB3    (0x3 << 4)
> +#define PEF2256_FMR1	        0x1D /* Framer Mode Register 1 */
> +#define   PEF2256_FMR1_XFS	  BIT(3)
> +#define   PEF2256_FMR1_ECM	  BIT(2)
> +/* SSD is defined on 2 bits. The other bit is on SIC1 register */
> +#define   PEF2256_FMR1_SSD_MASK   BIT(1)
> +#define     PEF2256_FMR1_SSD_2048   0
> +#define     PEF2256_FMR1_SSD_4096   BIT(1)
> +#define     PEF2256_FMR1_SSD_8192   0
> +#define     PEF2256_FMR1_SSD_16384  BIT(1)
> +#define PEF2256_FMR2	        0x1E /* Framer Mode Register 2 */
> +#define   PEF2256_FMR2_RFS_MASK	  (0x3 << 6)
> +#define     PEF2256_FMR2_RFS_DOUBLEFRAME      (0x0 << 6)
> +#define     PEF2256_FMR2_RFS_CRC4_MULTIFRAME  (0x2 << 6)
> +#define     PEF2256_FMR2_RFS_AUTO_MULTIFRAME  (0x3 << 6)
> +#define   PEF2256_FMR2_AXRA	  BIT(1)
> +#define PEF2256_LOOP	        0x1F /* Channel Loop-Back */
> +#define PEF2256_XSW	        0x20 /* Transmit Service Word */
> +#define   PEF2256_XSW_XSIS	  BIT(7)
> +#define   PEF2256_XSW_XTM	  BIT(6)
> +#define   PEF2256_XSW_XY_MASK	  (0x1f << 0)
> +#define     PEF2256_XSW_XY(_v)	    ((_v) & 0x1f)
> +#define PEF2256_XSP	        0x21 /* Transmit Spare Bits */
> +#define   PEF2256_XSP_XSIF	  BIT(2)
> +#define PEF2256_XC0	        0x22 /* Transmit Control 0 */
> +#define PEF2256_XC1	        0x23 /* Transmit Control 1 */
> +#define PEF2256_RC0	        0x24 /* Receive Control 0 */
> +#define   PEF2256_RC0_SWD	  BIT(7)
> +#define   PEF2256_RC0_ASY4	  BIT(6)
> +#define PEF2256_RC1	        0x25 /* Receive Control 1 */
> +#define PEF2256_XPM0	        0x26 /* Transmit Pulse Mask 0 */
> +#define PEF2256_XPM1	        0x27 /* Transmit Pulse Mask 1 */
> +#define PEF2256_XPM2	        0x28 /* Transmit Pulse Mask 2 */
> +#define   PEF2256_XPM2_XLT	  BIT(6)
> +#define PEF2256_TSWM	        0x29 /* Transparent Service Word Mask */
> +#define PEF2256_LIM0	        0x36 /* Line Interface Mode 0 */
> +#define   PEF2256_2X_LIM0_BIT3	  BIT(3) /* v2.x, described as a forced '1' bit */
> +#define   PEF2256_LIM0_MAS	  BIT(0)
> +#define PEF2256_LIM1	        0x37 /* Line Interface Mode 1 */
> +#define   PEF2256_12_LIM1_RIL_MASK   (0x7 << 4)
> +#define     PEF2256_12_LIM1_RIL_910    (0x0 << 4)
> +#define     PEF2256_12_LIM1_RIL_740    (0x1 << 4)
> +#define     PEF2256_12_LIM1_RIL_590    (0x2 << 4)
> +#define     PEF2256_12_LIM1_RIL_420    (0x3 << 4)
> +#define     PEF2256_12_LIM1_RIL_320    (0x4 << 4)
> +#define     PEF2256_12_LIM1_RIL_210    (0x5 << 4)
> +#define     PEF2256_12_LIM1_RIL_160    (0x6 << 4)
> +#define     PEF2256_12_LIM1_RIL_100    (0x7 << 4)
> +#define   PEF2256_2X_LIM1_RIL_MASK   (0x7 << 4)
> +#define     PEF2256_2X_LIM1_RIL_2250   (0x0 << 4)
> +#define     PEF2256_2X_LIM1_RIL_1100   (0x1 << 4)
> +#define     PEF2256_2X_LIM1_RIL_600    (0x2 << 4)
> +#define     PEF2256_2X_LIM1_RIL_350    (0x3 << 4)
> +#define     PEF2256_2X_LIM1_RIL_210    (0x4 << 4)
> +#define     PEF2256_2X_LIM1_RIL_140    (0x5 << 4)
> +#define     PEF2256_2X_LIM1_RIL_100    (0x6 << 4)
> +#define     PEF2256_2X_LIM1_RIL_50     (0x7 << 4)
> +#define PEF2256_PCD	        0x38 /* Pulse Count Detection */
> +#define PEF2256_PCR	        0x39 /* Pulse Count Recovery */
> +#define PEF2256_LIM2	        0x3A /* Line Interface Mode 2 */
> +#define   PEF2256_LIM2_SLT_MASK	  (0x3 << 4)
> +#define     PEF2256_LIM2_SLT_THR55  (0x0 << 4)
> +#define     PEF2256_LIM2_SLT_THR67  (0x1 << 4)
> +#define     PEF2256_LIM2_SLT_THR50  (0x2 << 4)
> +#define     PEF2256_LIM2_SLT_THR45  (0x3 << 4)
> +#define   PEF2256_LIM2_ELT	  BIT(2)
> +#define PEF2256_SIC1	        0x3E /* System Interface Control 1 */
> +#define   PEF2256_SIC1_SSC_MASK   (BIT(7) |  BIT(3))
> +#define     PEF2256_SIC1_SSC_2048   (0)
> +#define     PEF2256_SIC1_SSC_4096   BIT(3)
> +#define     PEF2256_SIC1_SSC_8192   BIT(7)
> +#define     PEF2256_SIC1_SSC_16384  (BIT(7) |  BIT(3))
> +/* SSD is defined on 2 bits. The other bit is on FMR1 register */
> +#define   PEF2256_SIC1_SSD_MASK   BIT(6)
> +#define     PEF2256_SIC1_SSD_2048   0
> +#define     PEF2256_SIC1_SSD_4096   0
> +#define     PEF2256_SIC1_SSD_8192   BIT(6)
> +#define     PEF2256_SIC1_SSD_16384  BIT(6)
> +#define   PEF2256_SIC1_RBS_MASK	  (0x3 << 4)
> +#define     PEF2256_SIC1_RBS_2FRAMES (0x0 << 4)
> +#define     PEF2256_SIC1_RBS_1FRAME  (0x1 << 4)
> +#define     PEF2256_SIC1_RBS_96BITS  (0x2 << 4)
> +#define     PEF2256_SIC1_RBS_BYPASS  (0x3 << 4)
> +#define   PEF2256_SIC1_XBS_MASK	  (0x3 << 0)
> +#define     PEF2256_SIC1_XBS_BYPASS  (0x0 << 0)
> +#define     PEF2256_SIC1_XBS_1FRAME  (0x1 << 0)
> +#define     PEF2256_SIC1_XBS_2FRAMES (0x2 << 0)
> +#define     PEF2256_SIC1_XBS_96BITS  (0x3 << 0)
> +#define PEF2256_SIC2	        0x3F /* System Interface Control 2 */
> +#define   PEF2256_SIC2_SICS_MASK       (0x7 << 1)
> +#define     PEF2256_SIC2_SICS(_v)        ((_v) << 1)
> +#define PEF2256_SIC3	        0x40 /* System Interface Control 3 */
> +#define   PEF2256_SIC3_RTRI	  BIT(5)
> +#define   PEF2256_SIC3_RESX	  BIT(3)
> +#define   PEF2256_SIC3_RESR	  BIT(2)
> +#define PEF2256_CMR1	        0x44 /* Clock Mode Register 1 */
> +#define   PEF2256_CMR1_RS_MASK	  (0x3 << 4)
> +#define     PEF2256_CMR1_RS_DPLL	   (0x0 << 4)
> +#define     PEF2256_CMR1_RS_DPLL_LOS_HIGH  (0x1 << 4)
> +#define     PEF2256_CMR1_RS_DCOR_2048	   (0x2 << 4)
> +#define     PEF2256_CMR1_RS_DCOR_8192	   (0x3 << 4)
> +#define   PEF2256_CMR1_DCS	  BIT(3)
> +#define PEF2256_CMR2	        0x45 /* Clock Mode Register 2 */
> +#define   PEF2256_CMR2_DCOXC	  BIT(5)
> +#define PEF2256_GCR	        0x46 /* Global Configuration Register */
> +#define   PEF2256_GCR_SCI	  BIT(6)
> +#define   PEF2256_GCR_ECMC	  BIT(4)
> +#define PEF2256_PC1	        0x80 /* Port Configuration 1 */
> +#define PEF2256_PC2	        0x81 /* Port Configuration 2 */
> +#define PEF2256_PC3	        0x82 /* Port Configuration 3 */
> +#define PEF2256_PC4	        0x83 /* Port Configuration 4 */
> +#define   PEF2256_12_PC_RPC_MASK  (0x7 << 4)
> +#define     PEF2256_12_PC_RPC_SYPR	(0x0 << 4)
> +#define     PEF2256_12_PC_RPC_RFM	(0x1 << 4)
> +#define     PEF2256_12_PC_RPC_RFMB	(0x2 << 4)
> +#define     PEF2256_12_PC_RPC_RSIGM	(0x3 << 4)
> +#define     PEF2256_12_PC_RPC_RSIG	(0x4 << 4)
> +#define     PEF2256_12_PC_RPC_DLR	(0x5 << 4)
> +#define     PEF2256_12_PC_RPC_FREEZE	(0x6 << 4)
> +#define     PEF2256_12_PC_RPC_RFSP	(0x7 << 4)
> +#define   PEF2256_12_PC_XPC_MASK  (0xf << 0)
> +#define     PEF2256_12_PC_XPC_SYPX	(0x0 << 0)
> +#define     PEF2256_12_PC_XPC_XFMS	(0x1 << 0)
> +#define     PEF2256_12_PC_XPC_XSIG	(0x2 << 0)
> +#define     PEF2256_12_PC_XPC_TCLK	(0x3 << 0)
> +#define     PEF2256_12_PC_XPC_XMFB	(0x4 << 0)
> +#define     PEF2256_12_PC_XPC_XSIGM	(0x5 << 0)
> +#define     PEF2256_12_PC_XPC_DLX	(0x6 << 0)
> +#define     PEF2256_12_PC_XPC_XCLK	(0x7 << 0)
> +#define     PEF2256_12_PC_XPC_XLT	(0x8 << 0)
> +#define   PEF2256_2X_PC_RPC_MASK  (0xf << 4)
> +#define     PEF2256_2X_PC_RPC_SYPR	(0x0 << 4)
> +#define     PEF2256_2X_PC_RPC_RFM	(0x1 << 4)
> +#define     PEF2256_2X_PC_RPC_RFMB	(0x2 << 4)
> +#define     PEF2256_2X_PC_RPC_RSIGM	(0x3 << 4)
> +#define     PEF2256_2X_PC_RPC_RSIG	(0x4 << 4)
> +#define     PEF2256_2X_PC_RPC_DLR	(0x5 << 4)
> +#define     PEF2256_2X_PC_RPC_FREEZE	(0x6 << 4)
> +#define     PEF2256_2X_PC_RPC_RFSP	(0x7 << 4)
> +#define     PEF2256_2X_PC_RPC_GPI	(0x9 << 4)
> +#define     PEF2256_2X_PC_RPC_GPOH	(0xa << 4)
> +#define     PEF2256_2X_PC_RPC_GPOL	(0xb << 4)
> +#define     PEF2256_2X_PC_RPC_LOS	(0xc << 4)
> +#define   PEF2256_2X_PC_XPC_MASK  (0xf << 0)
> +#define     PEF2256_2X_PC_XPC_SYPX	(0x0 << 0)
> +#define     PEF2256_2X_PC_XPC_XFMS	(0x1 << 0)
> +#define     PEF2256_2X_PC_XPC_XSIG	(0x2 << 0)
> +#define     PEF2256_2X_PC_XPC_TCLK	(0x3 << 0)
> +#define     PEF2256_2X_PC_XPC_XMFB	(0x4 << 0)
> +#define     PEF2256_2X_PC_XPC_XSIGM	(0x5 << 0)
> +#define     PEF2256_2X_PC_XPC_DLX	(0x6 << 0)
> +#define     PEF2256_2X_PC_XPC_XCLK	(0x7 << 0)
> +#define     PEF2256_2X_PC_XPC_XLT	(0x8 << 0)
> +#define     PEF2256_2X_PC_XPC_GPI	(0x9 << 0)
> +#define     PEF2256_2X_PC_XPC_GPOH	(0xa << 0)
> +#define     PEF2256_2X_PC_XPC_GPOL	(0xb << 0)
> +#define PEF2256_PC5	        0x84 /* Port Configuration 5 */
> +#define   PEF2256_PC5_CRP         BIT(0)
> +#define PEF2256_GPC1	        0x85 /* Global Port Configuration 1 */
> +#define   PEF2256_GPC1_CSFP_MASK	  (0x3 << 5)
> +#define   PEF2256_GPC1_CSFP_SEC_IN_HIGH   (0x0 << 5)
> +#define   PEF2256_GPC1_CSFP_SEC_OUT_HIGH  (0x1 << 5)
> +#define   PEF2256_GPC1_CSFP_FSC_OUT_HIGH  (0x2 << 5)
> +#define   PEF2256_GPC1_CSFP_FSC_OUT_LOW   (0x3 << 5)
> +#define PEF2256_PC6	        0x86 /* Port Configuration 6 */
> +#define PEF2256_GCM(_n)         (0x92 + _n - 1) /* Global Counter Mode n=1..8 */

Should be (0x92 + (_n) - 1) to avoid any risk.

> +#define PEF2256_GCM1	        0x92 /* Global Counter Mode 1 */
> +#define PEF2256_GCM2	        0x93 /* Global Counter Mode 2 */
> +#define PEF2256_GCM3	        0x94 /* Global Counter Mode 3 */
> +#define PEF2256_GCM4	        0x95 /* Global Counter Mode 4 */
> +#define PEF2256_GCM5	        0x96 /* Global Counter Mode 5 */
> +#define PEF2256_GCM6	        0x97 /* Global Counter Mode 6 */
> +#define PEF2256_GCM7	        0x98 /* Global Counter Mode 7 */
> +#define PEF2256_GCM8	        0x99 /* Global Counter Mode 8 */
> +
> +#define PEF2256_VSTR	0x4A /* Version Status Register */
> +#define   PEF2256_VSTR_VERSION_12  0x00
> +#define   PEF2256_VSTR_VERSION_21  0x10
> +#define   PEF2256_VSTR_VERSION_2x  0x05
> +#define PEF2256_FRS0	0x4C /* Framer Receive Status 0 */
> +#define   PEF2256_FRS0_LOS	BIT(7)
> +#define   PEF2256_FRS0_AIS	BIT(6)
> +#define PEF2256_ISR(_n) (0x68 + n) /* Interrupt Status Register (n=0..5) */
> +#define PEF2256_ISR0	0x68 /* Interrupt Status Register 0 */
> +#define PEF2256_ISR1	0x69 /* Interrupt Status Register 1 */
> +#define PEF2256_ISR2	0x6A /* Interrupt Status Register 2 */
> +#define PEF2256_ISR3	0x6B /* Interrupt Status Register 3 */
> +#define PEF2256_ISR4	0x6C /* Interrupt Status Register 4 */
> +#define PEF2256_ISR5	0x6D /* Interrupt Status Register 5 */
> +#define PEF2256_GIS	0x6E /* Global Interrupt Status */
> +#define   PEF2256_GIS_ISR(_n)	(1<<(n))

_n or n ?

> +#define PEF2256_WID	0xEC /* Wafer Identification Register */
> +#define   PEF2256_12_WID_MASK        0x03
> +#define     PEF2256_12_WID_VERSION_12  0x03
> +#define   PEF2256_2X_WID_MASK        0xc0
> +#define     PEF2256_2X_WID_VERSION_21  0x00
> +#define     PEF2256_2X_WID_VERSION_22  0x40
> +
> +/* IMR2/ISR2 Interrupts */
> +#define PEF2256_INT2_AIS  BIT(3)
> +#define PEF2256_INT2_LOS  BIT(2)
> +
> +enum pef2256_version {
> +	PEF2256_VERSION_UNKNOWN,
> +	PEF2256_VERSION_1_2,
> +	PEF2256_VERSION_2_1,
> +	PEF2256_VERSION_2_2,
> +};
> +
> +enum pef2256_frame_type {
> +	PEF2256_FRAME_E1_DOUBLEFRAME,
> +	PEF2256_FRAME_E1_CRC4_MULTIFRAME,
> +	PEF2256_FRAME_E1_AUTO_MULTIFRAME,
> +	PEF2256_FRAME_T1J1_4FRAME,
> +	PEF2256_FRAME_T1J1_12FRAME,
> +	PEF2256_FRAME_T1J1_24FRAME,
> +	PEF2256_FRAME_T1J1_72FRAME,
> +};
> +
> +struct pef2256_pinreg_desc {
> +	int offset;
> +	u8 mask;
> +};
> +
> +struct pef2256_function_desc {
> +	const char *name;
> +	const char * const*groups;
> +	unsigned int ngroups;
> +	u8 func_val;
> +};
> +
> +struct pef2256 {
> +	struct device *dev;
> +	void *__iomem regs;
> +	enum pef2256_version version;
> +	spinlock_t lock;
> +	struct clk *mclk;
> +	struct gpio_desc *reset_gpio;
> +	struct {
> +		struct pinctrl_desc pctrl_desc;
> +		const struct pef2256_function_desc *functions;
> +		unsigned int nfunctions;
> +	} pinctrl;
> +	bool is_e1;
> +	u32 sysclk_rate;
> +	u32 data_rate;
> +	bool is_tx_falling_edge;
> +	bool is_subordinate;
> +	enum pef2256_frame_type frame_type;
> +	u8 channel_phase;
> +	bool is_carrier_on;
> +	struct atomic_notifier_head event_notifier_list;
> +};
> +
> +static inline u8 pef2256_read8(struct pef2256 *pef2256, int offset)
> +{
> +	return ioread8(pef2256->regs + offset);
> +}
> +
> +static inline void pef2256_write8(struct pef2256 *pef2256, int offset, u8 val)
> +{
> +	iowrite8(val, pef2256->regs + offset);
> +}
> +
> +static inline void pef2256_clrbits8(struct pef2256 *pef2256, int offset, u8 clr)
> +{
> +	u8 v;
> +
> +	v = pef2256_read8(pef2256, offset);
> +	v &= ~clr;
> +	pef2256_write8(pef2256, offset, v);
> +}

Not sure it is worth the number of lines.

Would liekly be as good with just:

	pef2256_write8(pef2256, offset, pef2256_read8(pef2256, offset) & ~clr);

Same for all.


Also, it shouldn't need to be flagged 'inline' as it is defined in the C 
file it is used. GCC will decide by itself if it is worth inlining.

> +
> +static inline void pef2256_setbits8(struct pef2256 *pef2256, int offset, u8 set)
> +{
> +	u8 v;
> +
> +	v = pef2256_read8(pef2256, offset);
> +	v |= set;
> +	pef2256_write8(pef2256, offset, v);
> +}
> +
> +
> +static inline void pef2256_clrsetbits8(struct pef2256 *pef2256, int offset, u8 clr, u8 set)
> +{
> +	u8 v;
> +
> +	v = pef2256_read8(pef2256, offset);
> +	v &= ~clr;
> +	v |= set;
> +	pef2256_write8(pef2256, offset, v);
> +}
> +
> +static enum pef2256_version pef2256_get_version(struct pef2256 *pef2256)
> +{
> +	enum pef2256_version version;
> +	const char *version_txt;
> +	u8 vstr, wid;
> +
> +	vstr = pef2256_read8(pef2256, PEF2256_VSTR);
> +	wid = pef2256_read8(pef2256, PEF2256_WID);
> +
> +	switch (vstr) {
> +	case PEF2256_VSTR_VERSION_12:
> +		if ((wid & PEF2256_12_WID_MASK) == PEF2256_12_WID_VERSION_12) {
> +			version_txt = "1.2";
> +			version = PEF2256_VERSION_1_2;
> +			goto end;
> +		}
> +		break;
> +	case PEF2256_VSTR_VERSION_2x:
> +		switch (wid & PEF2256_2X_WID_MASK) {
> +		case PEF2256_2X_WID_VERSION_21:
> +			version_txt = "2.1 (2.x)";
> +			version = PEF2256_VERSION_2_1;
> +			goto end;
> +		case PEF2256_2X_WID_VERSION_22:
> +			version_txt = "2.2 (2.x)";
> +			version = PEF2256_VERSION_2_2;
> +			goto end;
> +		default:
> +			break;
> +		}
> +		break;
> +	case PEF2256_VSTR_VERSION_21:
> +		version_txt = "2.1";
> +		version = PEF2256_VERSION_2_1;
> +		goto end;
> +	default:
> +		break;

A default doing nothing is not needed unless the switch handles a enum 
and you have not covered all possible values.

My preference would be that you use the default to set:
version = PEF2256_VERSION_UNKNOWN;

then use an if (version == PEF2256_VERSION_UNKNOWN) / else below for the 
dev_err/dev_info.

> +	}
> +
> +	dev_err(pef2256->dev, "Unknown version (0x%02x, 0x%02x)\n", vstr, wid);
> +	return PEF2256_VERSION_UNKNOWN;
> +
> +end:
> +	dev_info(pef2256->dev, "Version %s detected\n", version_txt);
> +	return version;
> +}
> +
> +static int pef2256_12_setup_gcm(struct pef2256 *pef2256)
> +{
> +	static const u8 gcm_1544000[6] = {0xF0, 0x51, 0x00, 0x80, 0x00, 0x15};
> +	static const u8 gcm_2048000[6] = {0x00, 0x58, 0xD2, 0xC2, 0x00, 0x10};
> +	static const u8 gcm_8192000[6] = {0x00, 0x58, 0xD2, 0xC2, 0x03, 0x10};
> +	static const u8 gcm_10000000[6] = {0x90, 0x51, 0x81, 0x8F, 0x04, 0x10};
> +	static const u8 gcm_12352000[6] = {0xF0, 0x51, 0x00, 0x80, 0x07, 0x15};
> +	static const u8 gcm_16384000[6] = {0x00, 0x58, 0xD2, 0xC2, 0x07, 0x10};
> +	unsigned long mclk_rate;
> +	const u8 *gcm;
> +	int i;
> +
> +	mclk_rate = clk_get_rate(pef2256->mclk);
> +	switch (mclk_rate) {
> +	case 1544000:
> +		gcm = gcm_1544000;
> +		break;
> +	case 2048000:
> +		gcm = gcm_2048000;
> +		break;
> +	case 8192000:
> +		gcm = gcm_8192000;
> +		break;
> +	case 10000000:
> +		gcm = gcm_10000000;
> +		break;
> +	case 12352000:
> +		gcm = gcm_12352000;
> +		break;
> +	case 16384000:
> +		gcm = gcm_16384000;
> +		break;
> +	default:
> +		dev_err(pef2256->dev, "Unsupported v1.2 MCLK rate %lu\n", mclk_rate);
> +		return -EINVAL;
> +	}
> +	for (i = 0; i < 6; i++)
> +		pef2256_write8(pef2256, PEF2256_GCM(i+1), gcm[i]);
> +
> +	return 0;
> +}
> +
> +static int pef2256_2x_setup_gcm(struct pef2256 *pef2256)
> +{
> +	static const u8 gcm_1544000[8] = {0x00, 0x15, 0x00, 0x08, 0x00, 0x3F, 0x9C, 0xDF};
> +	static const u8 gcm_2048000[8] = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x2F, 0xDB, 0xDF};
> +	static const u8 gcm_8192000[8] = {0x00, 0x18, 0xFB, 0x0B, 0x00, 0x0B, 0xDB, 0xDF};
> +	static const u8 gcm_10000000[8] = {0x40, 0x1B, 0x3D, 0x0A, 0x00, 0x07, 0xC9, 0xDC};
> +	static const u8 gcm_12352000[8] = {0x00, 0x19, 0x00, 0x08, 0x01, 0x0A, 0x98, 0xDA};
> +	static const u8 gcm_16384000[8] = {0x00, 0x18, 0xFB, 0x0B, 0x01, 0x0B, 0xDB, 0xDF};
> +	unsigned long mclk_rate;
> +	const u8 *gcm;
> +	int i;
> +
> +	mclk_rate = clk_get_rate(pef2256->mclk);
> +	switch (mclk_rate) {
> +	case 1544000:
> +		gcm = gcm_1544000;
> +		break;
> +	case 2048000:
> +		gcm = gcm_2048000;
> +		break;
> +	case 8192000:
> +		gcm = gcm_8192000;
> +		break;
> +	case 10000000:
> +		gcm = gcm_10000000;
> +		break;
> +	case 12352000:
> +		gcm = gcm_12352000;
> +		break;
> +	case 16384000:
> +		gcm = gcm_16384000;
> +		break;
> +	default:
> +		dev_err(pef2256->dev, "Unsupported v2.x MCLK rate %lu\n", mclk_rate);
> +		return -EINVAL;
> +	}
> +	for (i = 0; i < 8; i++)
> +		pef2256_write8(pef2256, PEF2256_GCM(i+1), gcm[i]);
> +
> +	return 0;
> +}

This function and the previous one look very similar, can we merge them ?

> +
> +static int pef2256_setup_gcm(struct pef2256 *pef2256)
> +{
> +	return (pef2256->version == PEF2256_VERSION_1_2) ?
> +		pef2256_12_setup_gcm(pef2256) : pef2256_2x_setup_gcm(pef2256);
> +}
> +
> +static int pef2256_setup_e1(struct pef2256 *pef2256)
> +{
> +	u8 fmr1, fmr2, sic1;
> +	int ret;
> +
> +	/* Basic setup, Master clocking mode (GCM8..1) */
> +	ret = pef2256_setup_gcm(pef2256);
> +	if (ret)
> +		return ret;
> +
> +	/* RCLK output : DPLL clock, DCO-X enabled, DCO-X internal ref clock */
> +	pef2256_write8(pef2256, PEF2256_CMR1, 0x00);
> +
> +	/*
> +	 * SCLKR selected, SCLKX selected,
> +	 * receive synchro pulse sourced by SYPR,
> +	 * transmit synchro pulse sourced by SYPX
> +	 */
> +	pef2256_write8(pef2256, PEF2256_CMR2, 0x00);
> +
> +	/* NRZ coding, no alarm simulation */
> +	pef2256_write8(pef2256, PEF2256_FMR0, 0x00);
> +
> +	/*
> +	 * E1, frame format, 2 Mbit/s system data rate, no AIS
> +	 * transmission to remote end or system interface, payload loop
> +	 * off, transmit remote alarm on
> +	 */
> +	fmr1 = 0x00;
> +	fmr2 = PEF2256_FMR2_AXRA;
> +	switch (pef2256->frame_type) {
> +	case PEF2256_FRAME_E1_DOUBLEFRAME:
> +		fmr2 |= PEF2256_FMR2_RFS_DOUBLEFRAME;
> +		break;
> +	case PEF2256_FRAME_E1_CRC4_MULTIFRAME:
> +		fmr1 |= PEF2256_FMR1_XFS;
> +		fmr2 |= PEF2256_FMR2_RFS_CRC4_MULTIFRAME;
> +		break;
> +	case PEF2256_FRAME_E1_AUTO_MULTIFRAME:
> +		fmr1 |= PEF2256_FMR1_XFS;
> +		fmr2 |= PEF2256_FMR2_RFS_AUTO_MULTIFRAME;
> +		break;
> +	default:
> +		dev_err(pef2256->dev, "Unsupported frame type %d\n", pef2256->frame_type);
> +		return -EINVAL;
> +	}
> +	pef2256_write8(pef2256, PEF2256_FMR1, fmr1);
> +	pef2256_write8(pef2256, PEF2256_FMR2, fmr2);
> +
> +	/* E1 default for the receive slicer threshold */
> +	pef2256_write8(pef2256, PEF2256_LIM2, PEF2256_LIM2_SLT_THR50);
> +	if (!pef2256->is_subordinate) {
> +		/* SEC input, active high */
> +		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_SEC_IN_HIGH);
> +	} else {
> +		/* Loop-timed */
> +		pef2256_setbits8(pef2256, PEF2256_LIM2, PEF2256_LIM2_ELT);
> +		/* FSC output, active high */
> +		pef2256_write8(pef2256, PEF2256_GPC1, PEF2256_GPC1_CSFP_FSC_OUT_HIGH);
> +	}
> +
> +	/* internal second timer, power on */
> +	pef2256_write8(pef2256, PEF2256_GCR, 0x00);
> +
> +	/*
> +	 * slave mode, local loop off, mode short-haul
> +	 * In v2.x, bit3 is a forced 1 bit in the datasheet -> Need to be set.
> +	 */
> +	if (pef2256->version == PEF2256_VERSION_1_2)
> +		pef2256_write8(pef2256, PEF2256_LIM0, 0x00);
> +	else
> +		pef2256_write8(pef2256, PEF2256_LIM0, PEF2256_2X_LIM0_BIT3);
> +
> +	/* analog interface selected, remote loop off */
> +	pef2256_write8(pef2256, PEF2256_LIM1, 0x00);
> +
> +	/*
> +	 * SCLKR, SCLKX, RCLK configured to inputs,
> +	 * XFMS active low, CLK1 and CLK2 pin configuration
> +	 */
> +	pef2256_write8(pef2256, PEF2256_PC5, 0x00);
> +	pef2256_write8(pef2256, PEF2256_PC6, 0x00);
> +
> +	/*
> +	 * 2.048 MHz system clocking rate, receive buffer 2 frames, transmit
> +	 * buffer bypass, data sampled and transmitted on the falling edge of
> +	 * SCLKR/X, automatic freeze signaling, data is active in the first
> +	 * channel phase
> +	 */
> +	pef2256_write8(pef2256, PEF2256_SIC1, 0x00);
> +	pef2256_write8(pef2256, PEF2256_SIC2, 0x00);
> +	pef2256_write8(pef2256, PEF2256_SIC3, 0x00);
> +
> +	/* channel loop-back and single frame mode are disabled */
> +	pef2256_write8(pef2256, PEF2256_LOOP, 0x00);
> +
> +	/* all bits of the transmitted service word are cleared */
> +	pef2256_write8(pef2256, PEF2256_XSW, PEF2256_XSW_XY(0x1F));
> +	/* CAS disabled and clear spare bit values */
> +	pef2256_write8(pef2256, PEF2256_XSP, 0x00);
> +
> +	/* no transparent mode active */
> +	pef2256_write8(pef2256, PEF2256_TSWM, 0x00);
> +
> +	/*
> +	 * the transmit clock offset is cleared
> +	 * the transmit time slot offset is cleared
> +	 */
> +	pef2256_write8(pef2256, PEF2256_XC0, 0x00);
> +
> +	/* Keep default value for the transmit offset */
> +	pef2256_write8(pef2256, PEF2256_XC1, 0x9C);
> +
> +	/*
> +	 * transmit pulse mask, default value from datasheet
> +	 * transmitter in tristate mode
> +	 */
> +	if (pef2256->version == PEF2256_VERSION_1_2) {
> +		pef2256_write8(pef2256, PEF2256_XPM0, 0x7B);
> +		pef2256_write8(pef2256, PEF2256_XPM1, 0x03);
> +		pef2256_write8(pef2256, PEF2256_XPM2, PEF2256_XPM2_XLT | 0x00);
> +	} else {
> +		pef2256_write8(pef2256, PEF2256_XPM0, 0x9C);
> +		pef2256_write8(pef2256, PEF2256_XPM1, 0x03);
> +		pef2256_write8(pef2256, PEF2256_XPM2, PEF2256_XPM2_XLT | 0x00);
> +	}

Only first line seem different, could XPM1 and XPM2 be outside the if/else ?

> +
> +	/* "master" mode */
> +	if (!pef2256->is_subordinate)
> +		pef2256_setbits8(pef2256, PEF2256_LIM0, PEF2256_LIM0_MAS);
> +
> +	/* transmit line in normal operation */
> +	pef2256_clrbits8(pef2256, PEF2256_XPM2, PEF2256_XPM2_XLT);
> +
> +	if (pef2256->version == PEF2256_VERSION_1_2) {
> +		/* receive input threshold = 0,21V */
> +		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_12_LIM1_RIL_MASK,
> +				    PEF2256_12_LIM1_RIL_210);
> +	} else {
> +		/* receive input threshold = 0,21V */

Same comment twice, could be before the 'if' and remove the { } then ?

> +		pef2256_clrsetbits8(pef2256, PEF2256_LIM1, PEF2256_2X_LIM1_RIL_MASK,
> +				    PEF2256_2X_LIM1_RIL_210);
> +	}
> +	/* transmit line coding = HDB3 */
> +	pef2256_clrsetbits8(pef2256, PEF2256_FMR0, PEF2256_FMR0_XC_MASK,
> +			    PEF2256_FMR0_XC_HDB3);

Wouldn't that fit in a single line with the new recommended 100 char max 
line length ? I thing it would be more readable as a single line.

> +
> +	/* receive line coding = HDB3 */
> +	pef2256_clrsetbits8(pef2256, PEF2256_FMR0, PEF2256_FMR0_RC_MASK,
> +			    PEF2256_FMR0_RC_HDB3);
> +
> +	/* detection of LOS alarm = 176 pulses (ie (10 + 1) * 16) */
> +	pef2256_write8(pef2256, PEF2256_PCD, 10);
> +
> +	/* recovery of LOS alarm = 22 pulses (ie 21 + 1) */
> +	pef2256_write8(pef2256, PEF2256_PCR, 21);
> +
> +	/* DCO-X center frequency enabled */
> +	pef2256_setbits8(pef2256, PEF2256_CMR2, PEF2256_CMR2_DCOXC);
> +
> +	if (pef2256->is_subordinate) {
> +		/* select RCLK source = 2M */
> +		pef2256_clrsetbits8(pef2256, PEF2256_CMR1, PEF2256_CMR1_RS_MASK,
> +				    PEF2256_CMR1_RS_DCOR_2048);
> +		/* disable switching from RCLK to SYNC */
> +		pef2256_setbits8(pef2256, PEF2256_CMR1, PEF2256_CMR1_DCS);
> +	}

I'd move the comments into a single one before the 'if', the two 
comments are related.

> +
> +	if (pef2256->version != PEF2256_VERSION_1_2) {
> +		/* during inactive channel phase switch RDO/RSIG into tri-state */
> +		pef2256_setbits8(pef2256, PEF2256_SIC3, PEF2256_SIC3_RTRI);
> +	}

I'd put the comment before the 'if' and remove the { }

> +
> +	if (!pef2256->is_tx_falling_edge) {
> +		/* rising edge sync pulse transmit */

This comment doesn't seem to match the condition (rising versus falling).

> +		pef2256_clrsetbits8(pef2256, PEF2256_SIC3,
> +				    PEF2256_SIC3_RESR, PEF2256_SIC3_RESX);
> +	} else {
> +		/* rising edge sync pulse receive */

This comment doesn't seem to match the condition (receive versus tx).

> +		pef2256_clrsetbits8(pef2256, PEF2256_SIC3,
> +				    PEF2256_SIC3_RESX, PEF2256_SIC3_RESR);
> +	}
> +
> +	/* transmit offset counter (XCO10..0) = 4 */
> +	pef2256_write8(pef2256, PEF2256_XC0, 0);
> +	pef2256_write8(pef2256, PEF2256_XC1, 4);
> +	/* receive offset counter (RCO10..0) = 4 */
> +	pef2256_write8(pef2256, PEF2256_RC0, 0);
> +	pef2256_write8(pef2256, PEF2256_RC1, 4);
> +
> +	/* system clock rate */
> +	switch (pef2256->sysclk_rate) {
> +	case 2048000:
> +		sic1 = PEF2256_SIC1_SSC_2048;
> +		break;
> +	case 4096000:
> +		sic1 = PEF2256_SIC1_SSC_4096;
> +		break;
> +	case 8192000:
> +		sic1 = PEF2256_SIC1_SSC_8192;
> +		break;
> +	case 16384000:
> +		sic1 = PEF2256_SIC1_SSC_16384;
> +		break;
> +	default:
> +		dev_err(pef2256->dev, "Unsupported sysclk rate %u\n", pef2256->sysclk_rate);
> +		return -EINVAL;
> +	}
> +	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSC_MASK, sic1);
> +
> +	/* data clock rate */
> +	switch (pef2256->data_rate) {
> +	case 2048000:
> +		fmr1 = PEF2256_FMR1_SSD_2048;
> +		sic1 = PEF2256_SIC1_SSD_2048;
> +		break;
> +	case 4096000:
> +		fmr1 = PEF2256_FMR1_SSD_4096;
> +		sic1 = PEF2256_SIC1_SSD_4096;
> +		break;
> +	case 8192000:
> +		fmr1 = PEF2256_FMR1_SSD_8192;
> +		sic1 = PEF2256_SIC1_SSD_8192;
> +		break;
> +	case 16384000:
> +		fmr1 = PEF2256_FMR1_SSD_16384;
> +		sic1 = PEF2256_SIC1_SSD_16384;
> +		break;
> +	default:
> +		dev_err(pef2256->dev, "Unsupported data rate %u\n", pef2256->data_rate);
> +		return -EINVAL;
> +	}
> +	pef2256_clrsetbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_SSD_MASK, fmr1);
> +	pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_SSD_MASK, sic1);
> +
> +	/* channel phase */
> +	pef2256_clrsetbits8(pef2256, PEF2256_SIC2, PEF2256_SIC2_SICS_MASK,
> +			    PEF2256_SIC2_SICS(pef2256->channel_phase));
> +
> +	if (pef2256->is_subordinate) {
> +		/* transmit buffer size = 2 frames */
> +		pef2256_clrsetbits8(pef2256, PEF2256_SIC1, PEF2256_SIC1_XBS_MASK,
> +				    PEF2256_SIC1_XBS_2FRAMES);
> +		/* transmit transparent mode */
> +		pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XTM);
> +	}

Could this block get regrouped with the RX block depending on 
is_subordinate ?

> +
> +	/* error counter latched every 1s */
> +	pef2256_setbits8(pef2256, PEF2256_FMR1, PEF2256_FMR1_ECM);
> +	/* error counter mode COFA */
> +	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_ECMC);
> +	/* errors in service words have no influence */
> +	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_SWD);
> +	/* 4 consecutive incorrect FAS causes loss of sync */
> +	pef2256_setbits8(pef2256, PEF2256_RC0, PEF2256_RC0_ASY4);
> +	/* Si-Bit, Spare bit For International, FAS word */
> +	pef2256_setbits8(pef2256, PEF2256_XSW, PEF2256_XSW_XSIS);
> +	pef2256_setbits8(pef2256, PEF2256_XSP, PEF2256_XSP_XSIF);
> +
> +	/* port RCLK is output */
> +	pef2256_setbits8(pef2256, PEF2256_PC5, PEF2256_PC5_CRP);
> +	/* status changed interrupt at both up and down */
> +	pef2256_setbits8(pef2256, PEF2256_GCR, PEF2256_GCR_SCI);
> +
> +	/* Clear any ISR2 pending interrupts and unmask needed interrupts */
> +	pef2256_read8(pef2256, PEF2256_ISR2);
> +	pef2256_clrbits8(pef2256, PEF2256_IMR2, PEF2256_INT2_LOS | PEF2256_INT2_AIS);
> +
> +	/* reset lines */
> +	pef2256_write8(pef2256, PEF2256_CMDR, PEF2256_CMDR_RRES | PEF2256_CMDR_XRES);
> +	return 0;
> +}
> +
> +static int pef2256_setup(struct pef2256 *pef2256)
> +{
> +	if (!pef2256->is_e1) {
> +		dev_err(pef2256->dev, "Only E1 line is currently supported\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	return pef2256_setup_e1(pef2256);

In order to use future addition of other modes, I'd do:

	if (!pef2256->is_e1)
		return pef2256_setup_e1(pef2256);

	dev_err(pef2256->dev, "Only E1 line is currently supported\n");
	return -EOPNOTSUPP;

> +}
> +
> +
> +
> +static void pef2256_isr_default_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
> +{
> +	dev_warn(pef2256->dev, "ISR%u: 0x%02x not handled\n", nbr, isr);
> +}
> +
> +static bool pef2256_is_carrier_on(struct pef2256 *pef2256)
> +{
> +	u8 frs0;
> +
> +	frs0 = pef2256_read8(pef2256, PEF2256_FRS0);
> +	return !(frs0 & (PEF2256_FRS0_LOS | PEF2256_FRS0_AIS));
> +}
> +
> +static void pef2256_isr2_handler(struct pef2256 *pef2256, u8 nbr, u8 isr)
> +{
> +	bool is_changed = false;
> +	unsigned long flags;
> +	bool is_carrier_on;
> +
> +	if (isr & (PEF2256_INT2_LOS | PEF2256_INT2_AIS)) {
> +
> +		spin_lock_irqsave(&pef2256->lock, flags);
> +		is_carrier_on = pef2256_is_carrier_on(pef2256);
> +		if (is_carrier_on != pef2256->is_carrier_on) {
> +			pef2256->is_carrier_on = is_carrier_on;
> +			is_changed = true;
> +		}
> +		spin_unlock_irqrestore(&pef2256->lock, flags);

Do we really need spin_locks for that ?
If atomicity is really an issue, may we use atomic operations instead ?

> +
> +		if (is_changed)
> +			atomic_notifier_call_chain(&pef2256->event_notifier_list,
> +						   PEF2256_EVENT_CARRIER, NULL);
> +	}
> +}
> +
> +static irqreturn_t pef2256_irq_handler(int irq, void *priv)
> +{
> +	void (*pef2256_isr_handler[])(struct pef2256 *, u8, u8) = {
> +		[0] = pef2256_isr_default_handler,
> +		[1] = pef2256_isr_default_handler,
> +		[2] = pef2256_isr2_handler,
> +		[3] = pef2256_isr_default_handler,
> +		[4] = pef2256_isr_default_handler,
> +		[5] = pef2256_isr_default_handler
> +	};
> +	struct pef2256 *pef2256 = (struct pef2256 *)priv;
> +	u8 gis;
> +	u8 isr;
> +	u8 n;
> +
> +	gis = pef2256_read8(pef2256, PEF2256_GIS);
> +
> +	for (n = 0; n < ARRAY_SIZE(pef2256_isr_handler) ; n++) {
> +		if (gis & PEF2256_GIS_ISR(n)) {
> +			isr = pef2256_read8(pef2256, PEF2256_ISR(n));
> +			pef2256_isr_handler[n](pef2256, n, isr);
> +		}
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int pef2256_check_rates(struct pef2256 *pef2256, unsigned long sysclk_rate,
> +			       unsigned long data_rate)
> +{
> +	unsigned long rate;
> +
> +	switch (sysclk_rate) {
> +	case 2048000:
> +	case 4096000:
> +	case 8192000:
> +	case 16384000:
> +		break;
> +	default:
> +		dev_err(pef2256->dev, "Unsupported system clock rate %lu\n", sysclk_rate);
> +		return -EINVAL;
> +	}
> +
> +	for (rate = data_rate; rate <= data_rate * 4; rate *= 2) {
> +		if (rate == sysclk_rate)
> +			return 0;
> +	}
> +	dev_err(pef2256->dev, "Unsupported data rate %lu with system clock rate %lu\n",
> +		data_rate, sysclk_rate);
> +	return -EINVAL;
> +}
> +
> +static int pef2556_of_parse(struct pef2256 *pef2256, struct device_node *np)
> +{
> +	const char *str;
> +	int ret;
> +
> +	str = "e1";
> +	ret = of_property_read_string(np, "lantiq,line-interface", &str);
> +	if (ret && ret != -EINVAL) {
> +		dev_err(pef2256->dev, "%pOF: failed to read lantiq,line-interface\n",
> +			np);
> +		return ret;
> +	}
> +	if (!strcmp(str, "e1")) {
> +		pef2256->is_e1 = true;
> +	} else if (!strcmp(str, "t1j1")) {
> +		pef2256->is_e1 = false;
> +	} else {
> +		dev_err(pef2256->dev, "%pOF: Invalid lantiq,line-interface (%s)\n",
> +			np, str);
> +		return -EINVAL;
> +	}
> +	dev_dbg(pef2256->dev, "config: %s line\n", pef2256->is_e1 ? "E1" : "T1/J1");
> +
> +	pef2256->sysclk_rate = 2048000;
> +	ret = of_property_read_u32(np, "lantiq,sysclk-rate-hz", &pef2256->sysclk_rate);
> +	if (ret && ret != -EINVAL) {
> +		dev_err(pef2256->dev, "%pOF: failed to read lantiq,sysclk-rate-hz\n", np);
> +		return ret;
> +	}
> +	dev_dbg(pef2256->dev, "config: sysclk %u Hz\n", pef2256->sysclk_rate);
> +
> +	pef2256->data_rate = 2048000;
> +	ret = of_property_read_u32(np, "lantiq,data-rate-bps", &pef2256->data_rate);
> +	if (ret && ret != -EINVAL) {
> +		dev_err(pef2256->dev, "%pOF: failed to read lantiq,data-rate-bps\n", np);
> +		return ret;
> +	}
> +	dev_dbg(pef2256->dev, "config: data rate %u bps\n", pef2256->data_rate);
> +
> +	ret =  pef2256_check_rates(pef2256, pef2256->sysclk_rate, pef2256->data_rate);
> +	if (ret)
> +		return ret;
> +
> +	pef2256->is_tx_falling_edge = of_property_read_bool(np, "lantiq,clock-falling-edge");
> +	dev_dbg(pef2256->dev, "config: tx on %s edge\n",
> +		pef2256->is_tx_falling_edge ? "falling" : "rising");
> +
> +	pef2256->is_subordinate = of_property_read_bool(np, "lantiq,subordinate");
> +	dev_dbg(pef2256->dev, "config: subordinate %s\n",
> +		pef2256->is_subordinate ? "on" : "off");
> +
> +	str = pef2256->is_e1 ? "doubleframe" : "12frame";
> +	ret = of_property_read_string(np, "lantiq,frame-format", &str);
> +	if (ret && ret != -EINVAL) {
> +		dev_err(pef2256->dev, "%pOF: failed to read lantiq,frame-format\n",
> +			np);
> +		return ret;
> +	}
> +	if (pef2256->is_e1) {
> +		if (!strcmp(str, "doubleframe")) {
> +			pef2256->frame_type = PEF2256_FRAME_E1_DOUBLEFRAME;
> +		} else if (!strcmp(str, "crc4-multiframe")) {
> +			pef2256->frame_type = PEF2256_FRAME_E1_CRC4_MULTIFRAME;
> +		} else if (!strcmp(str, "auto-multiframe")) {
> +			pef2256->frame_type = PEF2256_FRAME_E1_AUTO_MULTIFRAME;
> +		} else {
> +			dev_err(pef2256->dev, "%pOF: Invalid lantiq,frame-format (%s)\n",
> +				np, str);
> +			return -EINVAL;
> +		}
> +	} else {
> +		if (!strcmp(str, "4frame")) {
> +			pef2256->frame_type = PEF2256_FRAME_T1J1_4FRAME;
> +		} else if (!strcmp(str, "12frame")) {
> +			pef2256->frame_type = PEF2256_FRAME_T1J1_12FRAME;
> +		} else if (!strcmp(str, "24frame")) {
> +			pef2256->frame_type = PEF2256_FRAME_T1J1_24FRAME;
> +		} else if (!strcmp(str, "72frame")) {
> +			pef2256->frame_type = PEF2256_FRAME_T1J1_72FRAME;
> +		} else {
> +			dev_err(pef2256->dev, "%pOF: Invalid lantiq,frame-format (%s)\n",
> +				np, str);
> +			return -EINVAL;
> +		}
> +	}
> +	dev_dbg(pef2256->dev, "config: frame type %d\n", pef2256->frame_type);
> +
> +	pef2256->channel_phase = 0;
> +	ret = of_property_read_u8(np, "lantiq,channel-phase", &pef2256->channel_phase);
> +	if (ret && ret != -EINVAL) {
> +		dev_err(pef2256->dev, "%pOF: failed to read lantiq,channel-phase\n",
> +			np);
> +		return ret;
> +	}
> +	if (pef2256->channel_phase >= pef2256->sysclk_rate / pef2256->data_rate) {
> +		dev_err(pef2256->dev, "%pOF: Invalid lantiq,channel-phase %u\n",
> +			np, pef2256->channel_phase);
> +		return -EINVAL;
> +	}
> +	dev_dbg(pef2256->dev, "config: channel phase %u\n", pef2256->channel_phase);
> +
> +	return 0;
> +}
> +
> +static int pef2256_get_groups_count(struct pinctrl_dev *pctldev)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +
> +	/* We map 1 group <-> 1 pin */
> +	return pef2256->pinctrl.pctrl_desc.npins;
> +}
> +
> +static const char *pef2256_get_group_name(struct pinctrl_dev *pctldev,
> +					  unsigned int selector)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +
> +	/* We map 1 group <-> 1 pin */
> +	return pef2256->pinctrl.pctrl_desc.pins[selector].name;
> +}
> +
> +static int pef2256_get_group_pins(struct pinctrl_dev *pctldev, unsigned int selector,
> +			     const unsigned int **pins,
> +			     unsigned int *num_pins)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +
> +	/* We map 1 group <-> 1 pin */
> +	*pins = &pef2256->pinctrl.pctrl_desc.pins[selector].number;
> +	*num_pins = 1;
> +
> +	return 0;
> +}
> +
> +static const struct pinctrl_ops pef2256_pctlops = {
> +	.get_groups_count	= pef2256_get_groups_count,
> +	.get_group_name		= pef2256_get_group_name,
> +	.get_group_pins		= pef2256_get_group_pins,
> +	.dt_node_to_map		= pinconf_generic_dt_node_to_map_pin,
> +	.dt_free_map		= pinconf_generic_dt_free_map,
> +};
> +
> +static int pef2256_get_functions_count(struct pinctrl_dev *pctldev)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +
> +	return pef2256->pinctrl.nfunctions;
> +}
> +
> +static const char *pef2256_get_function_name(struct pinctrl_dev *pctldev,
> +					     unsigned int selector)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +
> +	return pef2256->pinctrl.functions[selector].name;
> +}
> +
> +
> +static int pef2256_get_function_groups(struct pinctrl_dev *pctldev, unsigned int selector,
> +			 const char * const **groups,
> +			 unsigned * const num_groups)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +
> +	*groups = pef2256->pinctrl.functions[selector].groups;
> +	*num_groups = pef2256->pinctrl.functions[selector].ngroups;
> +	return 0;
> +}
> +
> +static int pef2256_set_mux(struct pinctrl_dev *pctldev, unsigned int func_selector,
> +			   unsigned int group_selector)
> +{
> +	struct pef2256 *pef2256 = pinctrl_dev_get_drvdata(pctldev);
> +	const struct pef2256_pinreg_desc *pinreg_desc;
> +	u8 func_val;
> +
> +	dev_dbg(pef2256->dev, "set %s to %s function\n",
> +		pef2256->pinctrl.pctrl_desc.pins[group_selector].name,
> +		pef2256->pinctrl.functions[func_selector].name);
> +
> +	/* We map 1 group <-> 1 pin */
> +	pinreg_desc = pef2256->pinctrl.pctrl_desc.pins[group_selector].drv_data;
> +	func_val = pef2256->pinctrl.functions[func_selector].func_val;
> +
> +	pef2256_clrsetbits8(pef2256, pinreg_desc->offset, pinreg_desc->mask,
> +			    func_val & pinreg_desc->mask);
> +
> +	return 0;
> +}
> +
> +static const struct pinmux_ops pef2256_pmxops = {
> +	.get_functions_count	= pef2256_get_functions_count,
> +	.get_function_name	= pef2256_get_function_name,
> +	.get_function_groups	= pef2256_get_function_groups,
> +	.set_mux		= pef2256_set_mux,
> +};
> +
> +#define PEF2256_PINCTRL_PIN(_number, _name, _offset, _mask) { \
> +	.number = _number, \
> +	.name = _name, \
> +	.drv_data = &(struct pef2256_pinreg_desc) { \
> +		.offset = _offset, \
> +		.mask = _mask, \
> +	}, \
> +}
> +
> +static const struct pinctrl_pin_desc pef2256_v12_pins[] = {
> +	PEF2256_PINCTRL_PIN(0, "RPA", PEF2256_PC1, PEF2256_12_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(1, "RPB", PEF2256_PC2, PEF2256_12_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(2, "RPC", PEF2256_PC3, PEF2256_12_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(3, "RPD", PEF2256_PC4, PEF2256_12_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(4, "XPA", PEF2256_PC1, PEF2256_12_PC_XPC_MASK),
> +	PEF2256_PINCTRL_PIN(5, "XPB", PEF2256_PC2, PEF2256_12_PC_XPC_MASK),
> +	PEF2256_PINCTRL_PIN(6, "XPC", PEF2256_PC3, PEF2256_12_PC_XPC_MASK),
> +	PEF2256_PINCTRL_PIN(7, "XPD", PEF2256_PC4, PEF2256_12_PC_XPC_MASK),
> +};
> +
> +static const struct pinctrl_pin_desc pef2256_v2x_pins[] = {
> +	PEF2256_PINCTRL_PIN(0, "RPA", PEF2256_PC1, PEF2256_2X_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(1, "RPB", PEF2256_PC2, PEF2256_2X_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(2, "RPC", PEF2256_PC3, PEF2256_2X_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(3, "RPD", PEF2256_PC4, PEF2256_2X_PC_RPC_MASK),
> +	PEF2256_PINCTRL_PIN(4, "XPA", PEF2256_PC1, PEF2256_2X_PC_XPC_MASK),
> +	PEF2256_PINCTRL_PIN(5, "XPB", PEF2256_PC2, PEF2256_2X_PC_XPC_MASK),
> +	PEF2256_PINCTRL_PIN(6, "XPC", PEF2256_PC3, PEF2256_2X_PC_XPC_MASK),
> +	PEF2256_PINCTRL_PIN(7, "XPD", PEF2256_PC4, PEF2256_2X_PC_XPC_MASK),
> +};
> +
> +static const char *const pef2256_rp_groups[] = { "RPA", "RPB", "RPC", "RPD" };
> +static const char *const pef2256_xp_groups[] = { "XPA", "XPB", "XPC", "XPD" };
> +static const char *const pef2256_all_groups[] = { "RPA", "RPB", "RPC", "RPD",
> +						  "XPA", "XPB", "XPC", "XPD" };
> +
> +#define PEF2256_FUNCTION(_name, _func_val, _groups) { \
> +	.name = _name, \
> +	.groups = _groups, \
> +	.ngroups = ARRAY_SIZE(_groups), \
> +	.func_val = _func_val, \
> +}
> +
> +static const struct pef2256_function_desc pef2256_v2x_functions[] = {
> +	PEF2256_FUNCTION("SYPR",   PEF2256_2X_PC_RPC_SYPR,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("RFM",    PEF2256_2X_PC_RPC_RFM,    pef2256_rp_groups),
> +	PEF2256_FUNCTION("RFMB",   PEF2256_2X_PC_RPC_RFMB,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("RSIGM",  PEF2256_2X_PC_RPC_RSIGM,  pef2256_rp_groups),
> +	PEF2256_FUNCTION("RSIG",   PEF2256_2X_PC_RPC_RSIG,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("DLR",    PEF2256_2X_PC_RPC_DLR,    pef2256_rp_groups),
> +	PEF2256_FUNCTION("FREEZE", PEF2256_2X_PC_RPC_FREEZE, pef2256_rp_groups),
> +	PEF2256_FUNCTION("RFSP",   PEF2256_2X_PC_RPC_RFSP,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("LOS",    PEF2256_2X_PC_RPC_LOS,    pef2256_rp_groups),
> +
> +	PEF2256_FUNCTION("SYPX",  PEF2256_2X_PC_XPC_SYPX,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XFMS",  PEF2256_2X_PC_XPC_XFMS,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XSIG",  PEF2256_2X_PC_XPC_XSIG,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("TCLK",  PEF2256_2X_PC_XPC_TCLK,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XMFB",  PEF2256_2X_PC_XPC_XMFB,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XSIGM", PEF2256_2X_PC_XPC_XSIGM, pef2256_xp_groups),
> +	PEF2256_FUNCTION("DLX",   PEF2256_2X_PC_XPC_DLX,   pef2256_xp_groups),
> +	PEF2256_FUNCTION("XCLK",  PEF2256_2X_PC_XPC_XCLK,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XLT",   PEF2256_2X_PC_XPC_XLT,   pef2256_xp_groups),
> +
> +	PEF2256_FUNCTION("GPI",  PEF2256_2X_PC_RPC_GPI | PEF2256_2X_PC_XPC_GPI,
> +			 pef2256_all_groups),
> +	PEF2256_FUNCTION("GPOH", PEF2256_2X_PC_RPC_GPOH | PEF2256_2X_PC_XPC_GPOH,
> +			 pef2256_all_groups),
> +	PEF2256_FUNCTION("GPOL", PEF2256_2X_PC_RPC_GPOL | PEF2256_2X_PC_XPC_GPOL,
> +			 pef2256_all_groups),
> +};
> +
> +static const struct pef2256_function_desc pef2256_v12_functions[] = {
> +	PEF2256_FUNCTION("SYPR",   PEF2256_12_PC_RPC_SYPR,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("RFM",    PEF2256_12_PC_RPC_RFM,    pef2256_rp_groups),
> +	PEF2256_FUNCTION("RFMB",   PEF2256_12_PC_RPC_RFMB,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("RSIGM",  PEF2256_12_PC_RPC_RSIGM,  pef2256_rp_groups),
> +	PEF2256_FUNCTION("RSIG",   PEF2256_12_PC_RPC_RSIG,   pef2256_rp_groups),
> +	PEF2256_FUNCTION("DLR",    PEF2256_12_PC_RPC_DLR,    pef2256_rp_groups),
> +	PEF2256_FUNCTION("FREEZE", PEF2256_12_PC_RPC_FREEZE, pef2256_rp_groups),
> +	PEF2256_FUNCTION("RFSP",   PEF2256_12_PC_RPC_RFSP,   pef2256_rp_groups),
> +
> +	PEF2256_FUNCTION("SYPX",  PEF2256_12_PC_XPC_SYPX,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XFMS",  PEF2256_12_PC_XPC_XFMS,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XSIG",  PEF2256_12_PC_XPC_XSIG,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("TCLK",  PEF2256_12_PC_XPC_TCLK,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XMFB",  PEF2256_12_PC_XPC_XMFB,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XSIGM", PEF2256_12_PC_XPC_XSIGM, pef2256_xp_groups),
> +	PEF2256_FUNCTION("DLX",   PEF2256_12_PC_XPC_DLX,   pef2256_xp_groups),
> +	PEF2256_FUNCTION("XCLK",  PEF2256_12_PC_XPC_XCLK,  pef2256_xp_groups),
> +	PEF2256_FUNCTION("XLT",   PEF2256_12_PC_XPC_XLT,   pef2256_xp_groups),
> +};
> +
> +
> +static int pef2256_register_pinctrl(struct pef2256 *pef2256)
> +{
> +	struct pinctrl_dev	*pctrl;
> +
> +	pef2256->pinctrl.pctrl_desc.name    = dev_name(pef2256->dev);
> +	pef2256->pinctrl.pctrl_desc.owner   = THIS_MODULE;
> +	pef2256->pinctrl.pctrl_desc.pctlops = &pef2256_pctlops;
> +	pef2256->pinctrl.pctrl_desc.pmxops  = &pef2256_pmxops;
> +	if (pef2256->version == PEF2256_VERSION_1_2) {
> +		pef2256->pinctrl.pctrl_desc.pins  = pef2256_v12_pins;
> +		pef2256->pinctrl.pctrl_desc.npins = ARRAY_SIZE(pef2256_v12_pins);
> +		pef2256->pinctrl.functions  = pef2256_v12_functions;
> +		pef2256->pinctrl.nfunctions = ARRAY_SIZE(pef2256_v12_functions);
> +	} else {
> +		pef2256->pinctrl.pctrl_desc.pins  = pef2256_v2x_pins;
> +		pef2256->pinctrl.pctrl_desc.npins = ARRAY_SIZE(pef2256_v2x_pins);
> +		pef2256->pinctrl.functions  = pef2256_v2x_functions;
> +		pef2256->pinctrl.nfunctions = ARRAY_SIZE(pef2256_v2x_functions);
> +	}
> +
> +
> +	pctrl = devm_pinctrl_register(pef2256->dev, &pef2256->pinctrl.pctrl_desc, pef2256);
> +	if (IS_ERR(pctrl)) {
> +		dev_err(pef2256->dev, "pinctrl driver registration failed\n");
> +		return PTR_ERR(pctrl);
> +	}
> +
> +	return 0;
> +}
> +
> +static void pef2256_reset_pinmux(struct pef2256 *pef2256)
> +{
> +	u8 val;
> +	/*
> +	 * Reset values cannot be used.
> +	 * They define the SYPR/SYPX pin mux for all the RPx and XPx pins and
> +	 * Only one pin can be muxed to SYPR and one pin can be muxed to SYPX.
> +	 * Choose here an other reset value.
> +	 */
> +	if (pef2256->version == PEF2256_VERSION_1_2)
> +		val = PEF2256_12_PC_XPC_XCLK | PEF2256_12_PC_RPC_RFSP;
> +	else
> +		val = PEF2256_2X_PC_XPC_GPI | PEF2256_2X_PC_RPC_GPI;
> +
> +	pef2256_write8(pef2256, PEF2256_PC1, val);
> +	pef2256_write8(pef2256, PEF2256_PC2, val);
> +	pef2256_write8(pef2256, PEF2256_PC3, val);
> +	pef2256_write8(pef2256, PEF2256_PC4, val);
> +}
> +
> +static ssize_t subordinate_show(struct device *dev, struct device_attribute *attr,
> +				char *buf)
> +{
> +	struct pef2256 *pef2256 = dev_get_drvdata(dev);
> +
> +	return sysfs_emit(buf, "%d\n", pef2256->is_subordinate);
> +}
> +
> +static ssize_t subordinate_store(struct device *dev, struct device_attribute *attr,
> +				 const char *buf, size_t count)
> +{
> +	struct pef2256 *pef2256 = dev_get_drvdata(dev);
> +	int ret;
> +
> +	if (strtobool(buf, &pef2256->is_subordinate) < 0)
> +		return -EINVAL;
> +
> +	ret = pef2256_setup(pef2256);
> +	if (ret)
> +		return ret;
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR_RW(subordinate);
> +
> +static const struct attribute_group pef2256_attribute_group = {
> +	.attrs = (struct attribute *[]) {
> +		&dev_attr_subordinate.attr,
> +		NULL,
> +	},
> +};
> +
> +static int pef2256_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct pef2256 *pef2256;
> +	int ret;
> +	int irq;
> +
> +	pef2256 = devm_kzalloc(&pdev->dev, sizeof(*pef2256), GFP_KERNEL);
> +	if (!pef2256)
> +		return -ENOMEM;
> +
> +	pef2256->dev = &pdev->dev;
> +	spin_lock_init(&pef2256->lock);
> +	ATOMIC_INIT_NOTIFIER_HEAD(&pef2256->event_notifier_list);
> +
> +	pef2256->regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(pef2256->regs))
> +		return PTR_ERR(pef2256->regs);
> +
> +	pef2256->mclk = devm_clk_get_enabled(&pdev->dev, "mclk");
> +	if (IS_ERR(pef2256->mclk))
> +		return PTR_ERR(pef2256->mclk);
> +	dev_dbg(pef2256->dev, "mclk %lu Hz\n", clk_get_rate(pef2256->mclk));
> +
> +	/* Reset the component. The MCLK clock must be active during reset */
> +	pef2256->reset_gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(pef2256->reset_gpio))
> +		return PTR_ERR(pef2256->reset_gpio);
> +	if (pef2256->reset_gpio) {
> +		gpiod_set_value_cansleep(pef2256->reset_gpio, 1);
> +		udelay(10);
> +		gpiod_set_value_cansleep(pef2256->reset_gpio, 0);
> +		udelay(10);
> +	}
> +
> +	pef2256->version = pef2256_get_version(pef2256);
> +	if (pef2256->version == PEF2256_VERSION_UNKNOWN)
> +		return -ENODEV;
> +
> +	ret = pef2556_of_parse(pef2256, np);
> +	if (ret)
> +		return ret;
> +
> +	/* Disable interrupts */
> +	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
> +
> +	/* Clear any pending interrupts */
> +	pef2256_read8(pef2256, PEF2256_ISR0);
> +	pef2256_read8(pef2256, PEF2256_ISR1);
> +	pef2256_read8(pef2256, PEF2256_ISR2);
> +	pef2256_read8(pef2256, PEF2256_ISR3);
> +	pef2256_read8(pef2256, PEF2256_ISR4);
> +	pef2256_read8(pef2256, PEF2256_ISR5);
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		return irq;
> +	ret = devm_request_irq(pef2256->dev, irq, pef2256_irq_handler, 0, "pef2256", pef2256);
> +	if (ret < 0)
> +		return ret;
> +
> +	pef2256_reset_pinmux(pef2256);
> +	ret = pef2256_register_pinctrl(pef2256);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * We are going to reset the E1 lines during setup() call and the ISR2
> +	 * interrupt used to detect the carrier state changed is masked.
> +	 * It is time to initialize our internal carrier state flag.
> +	 */
> +	pef2256->is_carrier_on = false;
> +
> +	ret = pef2256_setup(pef2256);
> +	if (ret)
> +		return ret;
> +
> +	platform_set_drvdata(pdev, pef2256);
> +
> +	ret = sysfs_create_group(&pef2256->dev->kobj, &pef2256_attribute_group);
> +	if (ret < 0) {
> +		dev_err(pef2256->dev, "sysfs registration failed (%d)\n", ret);
> +		platform_set_drvdata(pdev, NULL);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int pef2256_remove(struct platform_device *pdev)
> +{
> +	struct pef2256 *pef2256 = platform_get_drvdata(pdev);
> +
> +	/* Disable interrupts */
> +	pef2256_write8(pef2256, PEF2256_IMR0, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR1, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR2, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR3, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR4, 0xff);
> +	pef2256_write8(pef2256, PEF2256_IMR5, 0xff);
> +
> +	sysfs_remove_group(&pef2256->dev->kobj, &pef2256_attribute_group);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id pef2256_id_table[] = {
> +	{ .compatible = "lantiq,pef2256" },
> +	{} /* sentinel */
> +};
> +MODULE_DEVICE_TABLE(of, pef2256_id_table);
> +
> +static struct platform_driver pef2256_driver = {
> +	.driver = {
> +		.name = "lantiq-pef2256",
> +		.of_match_table = of_match_ptr(pef2256_id_table),
> +	},
> +	.probe = pef2256_probe,
> +	.remove = pef2256_remove,
> +};
> +module_platform_driver(pef2256_driver);
> +
> +struct pef2256 *pef2256_get_byphandle(struct device_node *np, const char *phandle_name)
> +{
> +	struct device_node *pef2256_np;
> +	struct platform_device *pdev;
> +	struct pef2256 *pef2256;
> +
> +	pef2256_np = of_parse_phandle(np, phandle_name, 0);
> +	if (!pef2256_np)
> +		return ERR_PTR(-EINVAL);
> +
> +	if (!of_match_node(pef2256_driver.driver.of_match_table, pef2256_np)) {
> +		of_node_put(pef2256_np);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	pdev = of_find_device_by_node(pef2256_np);
> +	of_node_put(pef2256_np);
> +	if (!pdev)
> +		return ERR_PTR(-ENODEV);
> +
> +	pef2256 = platform_get_drvdata(pdev);
> +	if (!pef2256) {
> +		platform_device_put(pdev);
> +		return ERR_PTR(-EPROBE_DEFER);
> +	}
> +
> +	return pef2256;
> +}
> +EXPORT_SYMBOL(pef2256_get_byphandle);
> +
> +void pef2256_put(struct pef2256 *pef2256)
> +{
> +	put_device(pef2256->dev);
> +}
> +EXPORT_SYMBOL(pef2256_put);
> +
> +static void devm_pef2256_release(struct device *dev, void *res)
> +{
> +	struct pef2256 **pef2256 = res;
> +
> +	pef2256_put(*pef2256);
> +}
> +
> +struct pef2256 *devm_pef2256_get_byphandle(struct device *dev, struct device_node *np,
> +					   const char *phandle_name)
> +{
> +	struct pef2256 *pef2256;
> +	struct pef2256 **dr;
> +
> +	dr = devres_alloc(devm_pef2256_release, sizeof(*dr), GFP_KERNEL);
> +	if (!dr)
> +		return ERR_PTR(-ENOMEM);
> +
> +	pef2256 = pef2256_get_byphandle(np, phandle_name);
> +	if (!IS_ERR(pef2256)) {
> +		*dr = pef2256;
> +		devres_add(dev, dr);
> +	} else {
> +		devres_free(dr);
> +	}
> +
> +	return pef2256;
> +}
> +EXPORT_SYMBOL(devm_pef2256_get_byphandle);
> +
> +int pef2256_register_event_notifier(struct pef2256 *pef2256, struct notifier_block *nb)
> +{
> +	return atomic_notifier_chain_register(&pef2256->event_notifier_list, nb);
> +}
> +EXPORT_SYMBOL_GPL(pef2256_register_event_notifier);
> +
> +int pef2256_unregister_event_notifier(struct pef2256 *pef2256, struct notifier_block *nb)
> +{
> +	return atomic_notifier_chain_unregister(&pef2256->event_notifier_list, nb);
> +}
> +EXPORT_SYMBOL_GPL(pef2256_unregister_event_notifier);
> +
> +bool pef2256_get_carrier(struct pef2256 *pef2256)
> +{
> +	unsigned long flags;
> +	bool is_carrier_on;
> +
> +	spin_lock_irqsave(&pef2256->lock, flags);
> +	is_carrier_on = pef2256->is_carrier_on;
> +	spin_unlock_irqrestore(&pef2256->lock, flags);
> +
> +	return is_carrier_on;
> +}
> +EXPORT_SYMBOL_GPL(pef2256_get_carrier);
> +
> +MODULE_AUTHOR("Herve Codina <herve.codina@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("PEF2256 driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/pef2256.h b/include/linux/pef2256.h
> new file mode 100644
> index 000000000000..6c8d173595b1
> --- /dev/null
> +++ b/include/linux/pef2256.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * PEF2256 management
> + *
> + * Copyright 2023 CS GROUP France
> + *
> + * Author: Herve Codina <herve.codina@xxxxxxxxxxx>
> + */
> +#ifndef __PEF2256_H__
> +#define __PEF2256_H__
> +
> +#include <linux/types.h>
> +
> +struct pef2256;
> +struct device_node;
> +struct device;
> +struct notifier_block;
> +
> +struct pef2256 *pef2256_get_byphandle(struct device_node *np, const char *phandle_name);
> +void pef2256_put(struct pef2256 *pef2256);
> +struct pef2256 *devm_pef2256_get_byphandle(struct device *dev, struct device_node *np,
> +					   const char *phandle_name);
> +
> +
> +enum pef2256_event {
> +	PEF2256_EVENT_CARRIER, /* Carrier state changed */
> +};
> +
> +/* The nb.notifier_call function registered must not sleep */
> +int pef2256_register_event_notifier(struct pef2256 *pef2256, struct notifier_block *nb);
> +int pef2256_unregister_event_notifier(struct pef2256 *pef2256, struct notifier_block *nb);
> +
> +/* Retrieve carrier state. true: carrier on, false: carrier off */
> +bool pef2256_get_carrier(struct pef2256 *pef2256);
> +
> +#endif /* __PEF2256_H__ */




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