drivers/gpu/drm/i915/dvo_ns2501.c - kernel/msm-4.9 - Gitiles

 /*
  *
  * Copyright (c) 2012 Gilles Dartiguelongue, Thomas Richter
  *
  * All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sub license, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice (including the
  * next paragraph) shall be included in all copies or substantial portions
  * of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  */

 #include "dvo.h"
 #include "i915_reg.h"
 #include "i915_drv.h"

 #define NS2501_VID 0x1305
 #define NS2501_DID 0x6726

 #define NS2501_VID_LO 0x00
 #define NS2501_VID_HI 0x01
 #define NS2501_DID_LO 0x02
 #define NS2501_DID_HI 0x03
 #define NS2501_REV 0x04
 #define NS2501_RSVD 0x05
 #define NS2501_FREQ_LO 0x06
 #define NS2501_FREQ_HI 0x07

 #define NS2501_REG8 0x08
 #define NS2501_8_VEN (1<<5)
 #define NS2501_8_HEN (1<<4)
 #define NS2501_8_DSEL (1<<3)
 #define NS2501_8_BPAS (1<<2)
 #define NS2501_8_RSVD (1<<1)
 #define NS2501_8_PD (1<<0)

 #define NS2501_REG9 0x09
 #define NS2501_9_VLOW (1<<7)
 #define NS2501_9_MSEL_MASK (0x7<<4)
 #define NS2501_9_TSEL (1<<3)
 #define NS2501_9_RSEN (1<<2)
 #define NS2501_9_RSVD (1<<1)
 #define NS2501_9_MDI (1<<0)

 #define NS2501_REGC 0x0c

 enum {
 	MODE_640x480,
 	MODE_800x600,
 	MODE_1024x768,
 };

 struct ns2501_reg {
 	 uint8_t offset;
 	 uint8_t value;
 };

 /*
  * Magic values based on what the BIOS on
  * Fujitsu-Siemens Lifebook S6010 programs (1024x768 panel).
  */
 static const struct ns2501_reg regs_1024x768[][86] = {
 	[MODE_640x480] = {
 		[0] = { .offset = 0x0a, .value = 0x81, },
 		[1] = { .offset = 0x18, .value = 0x07, },
 		[2] = { .offset = 0x19, .value = 0x00, },
 		[3] = { .offset = 0x1a, .value = 0x00, },
 		[4] = { .offset = 0x1b, .value = 0x11, },
 		[5] = { .offset = 0x1c, .value = 0x54, },
 		[6] = { .offset = 0x1d, .value = 0x03, },
 		[7] = { .offset = 0x1e, .value = 0x02, },
 		[8] = { .offset = 0xf3, .value = 0x90, },
 		[9] = { .offset = 0xf9, .value = 0x00, },
 		[10] = { .offset = 0xc1, .value = 0x90, },
 		[11] = { .offset = 0xc2, .value = 0x00, },
 		[12] = { .offset = 0xc3, .value = 0x0f, },
 		[13] = { .offset = 0xc4, .value = 0x03, },
 		[14] = { .offset = 0xc5, .value = 0x16, },
 		[15] = { .offset = 0xc6, .value = 0x00, },
 		[16] = { .offset = 0xc7, .value = 0x02, },
 		[17] = { .offset = 0xc8, .value = 0x02, },
 		[18] = { .offset = 0xf4, .value = 0x00, },
 		[19] = { .offset = 0x80, .value = 0xff, },
 		[20] = { .offset = 0x81, .value = 0x07, },
 		[21] = { .offset = 0x82, .value = 0x3d, },
 		[22] = { .offset = 0x83, .value = 0x05, },
 		[23] = { .offset = 0x94, .value = 0x00, },
 		[24] = { .offset = 0x95, .value = 0x00, },
 		[25] = { .offset = 0x96, .value = 0x05, },
 		[26] = { .offset = 0x97, .value = 0x00, },
 		[27] = { .offset = 0x9a, .value = 0x88, },
 		[28] = { .offset = 0x9b, .value = 0x00, },
 		[29] = { .offset = 0x98, .value = 0x00, },
 		[30] = { .offset = 0x99, .value = 0x00, },
 		[31] = { .offset = 0xf7, .value = 0x88, },
 		[32] = { .offset = 0xf8, .value = 0x0a, },
 		[33] = { .offset = 0x9c, .value = 0x24, },
 		[34] = { .offset = 0x9d, .value = 0x00, },
 		[35] = { .offset = 0x9e, .value = 0x25, },
 		[36] = { .offset = 0x9f, .value = 0x03, },
 		[37] = { .offset = 0xa0, .value = 0x28, },
 		[38] = { .offset = 0xa1, .value = 0x01, },
 		[39] = { .offset = 0xa2, .value = 0x28, },
 		[40] = { .offset = 0xa3, .value = 0x05, },
 		[41] = { .offset = 0xb6, .value = 0x09, },
 		[42] = { .offset = 0xb8, .value = 0x00, },
 		[43] = { .offset = 0xb9, .value = 0xa0, },
 		[44] = { .offset = 0xba, .value = 0x00, },
 		[45] = { .offset = 0xbb, .value = 0x20, },
 		[46] = { .offset = 0x10, .value = 0x00, },
 		[47] = { .offset = 0x11, .value = 0xa0, },
 		[48] = { .offset = 0x12, .value = 0x02, },
 		[49] = { .offset = 0x20, .value = 0x00, },
 		[50] = { .offset = 0x22, .value = 0x00, },
 		[51] = { .offset = 0x23, .value = 0x00, },
 		[52] = { .offset = 0x24, .value = 0x00, },
 		[53] = { .offset = 0x25, .value = 0x00, },
 		[54] = { .offset = 0x8c, .value = 0x10, },
 		[55] = { .offset = 0x8d, .value = 0x02, },
 		[56] = { .offset = 0x8e, .value = 0x10, },
 		[57] = { .offset = 0x8f, .value = 0x00, },
 		[58] = { .offset = 0x90, .value = 0xff, },
 		[59] = { .offset = 0x91, .value = 0x07, },
 		[60] = { .offset = 0x92, .value = 0xa0, },
 		[61] = { .offset = 0x93, .value = 0x02, },
 		[62] = { .offset = 0xa5, .value = 0x00, },
 		[63] = { .offset = 0xa6, .value = 0x00, },
 		[64] = { .offset = 0xa7, .value = 0x00, },
 		[65] = { .offset = 0xa8, .value = 0x00, },
 		[66] = { .offset = 0xa9, .value = 0x04, },
 		[67] = { .offset = 0xaa, .value = 0x70, },
 		[68] = { .offset = 0xab, .value = 0x4f, },
 		[69] = { .offset = 0xac, .value = 0x00, },
 		[70] = { .offset = 0xa4, .value = 0x84, },
 		[71] = { .offset = 0x7e, .value = 0x18, },
 		[72] = { .offset = 0x84, .value = 0x00, },
 		[73] = { .offset = 0x85, .value = 0x00, },
 		[74] = { .offset = 0x86, .value = 0x00, },
 		[75] = { .offset = 0x87, .value = 0x00, },
 		[76] = { .offset = 0x88, .value = 0x00, },
 		[77] = { .offset = 0x89, .value = 0x00, },
 		[78] = { .offset = 0x8a, .value = 0x00, },
 		[79] = { .offset = 0x8b, .value = 0x00, },
 		[80] = { .offset = 0x26, .value = 0x00, },
 		[81] = { .offset = 0x27, .value = 0x00, },
 		[82] = { .offset = 0xad, .value = 0x00, },
 		[83] = { .offset = 0x08, .value = 0x30, }, /* 0x31 */
 		[84] = { .offset = 0x41, .value = 0x00, },
 		[85] = { .offset = 0xc0, .value = 0x05, },
 	},
 	[MODE_800x600] = {
 		[0] = { .offset = 0x0a, .value = 0x81, },
 		[1] = { .offset = 0x18, .value = 0x07, },
 		[2] = { .offset = 0x19, .value = 0x00, },
 		[3] = { .offset = 0x1a, .value = 0x00, },
 		[4] = { .offset = 0x1b, .value = 0x19, },
 		[5] = { .offset = 0x1c, .value = 0x64, },
 		[6] = { .offset = 0x1d, .value = 0x02, },
 		[7] = { .offset = 0x1e, .value = 0x02, },
 		[8] = { .offset = 0xf3, .value = 0x90, },
 		[9] = { .offset = 0xf9, .value = 0x00, },
 		[10] = { .offset = 0xc1, .value = 0xd7, },
 		[11] = { .offset = 0xc2, .value = 0x00, },
 		[12] = { .offset = 0xc3, .value = 0xf8, },
 		[13] = { .offset = 0xc4, .value = 0x03, },
 		[14] = { .offset = 0xc5, .value = 0x1a, },
 		[15] = { .offset = 0xc6, .value = 0x00, },
 		[16] = { .offset = 0xc7, .value = 0x73, },
 		[17] = { .offset = 0xc8, .value = 0x02, },
 		[18] = { .offset = 0xf4, .value = 0x00, },
 		[19] = { .offset = 0x80, .value = 0x27, },
 		[20] = { .offset = 0x81, .value = 0x03, },
 		[21] = { .offset = 0x82, .value = 0x41, },
 		[22] = { .offset = 0x83, .value = 0x05, },
 		[23] = { .offset = 0x94, .value = 0x00, },
 		[24] = { .offset = 0x95, .value = 0x00, },
 		[25] = { .offset = 0x96, .value = 0x05, },
 		[26] = { .offset = 0x97, .value = 0x00, },
 		[27] = { .offset = 0x9a, .value = 0x88, },
 		[28] = { .offset = 0x9b, .value = 0x00, },
 		[29] = { .offset = 0x98, .value = 0x00, },
 		[30] = { .offset = 0x99, .value = 0x00, },
 		[31] = { .offset = 0xf7, .value = 0x88, },
 		[32] = { .offset = 0xf8, .value = 0x06, },
 		[33] = { .offset = 0x9c, .value = 0x23, },
 		[34] = { .offset = 0x9d, .value = 0x00, },
 		[35] = { .offset = 0x9e, .value = 0x25, },
 		[36] = { .offset = 0x9f, .value = 0x03, },
 		[37] = { .offset = 0xa0, .value = 0x28, },
 		[38] = { .offset = 0xa1, .value = 0x01, },
 		[39] = { .offset = 0xa2, .value = 0x28, },
 		[40] = { .offset = 0xa3, .value = 0x05, },
 		[41] = { .offset = 0xb6, .value = 0x09, },
 		[42] = { .offset = 0xb8, .value = 0x30, },
 		[43] = { .offset = 0xb9, .value = 0xc8, },
 		[44] = { .offset = 0xba, .value = 0x00, },
 		[45] = { .offset = 0xbb, .value = 0x20, },
 		[46] = { .offset = 0x10, .value = 0x20, },
 		[47] = { .offset = 0x11, .value = 0xc8, },
 		[48] = { .offset = 0x12, .value = 0x02, },
 		[49] = { .offset = 0x20, .value = 0x00, },
 		[50] = { .offset = 0x22, .value = 0x00, },
 		[51] = { .offset = 0x23, .value = 0x00, },
 		[52] = { .offset = 0x24, .value = 0x00, },
 		[53] = { .offset = 0x25, .value = 0x00, },
 		[54] = { .offset = 0x8c, .value = 0x10, },
 		[55] = { .offset = 0x8d, .value = 0x02, },
 		[56] = { .offset = 0x8e, .value = 0x04, },
 		[57] = { .offset = 0x8f, .value = 0x00, },
 		[58] = { .offset = 0x90, .value = 0xff, },
 		[59] = { .offset = 0x91, .value = 0x07, },
 		[60] = { .offset = 0x92, .value = 0xa0, },
 		[61] = { .offset = 0x93, .value = 0x02, },
 		[62] = { .offset = 0xa5, .value = 0x00, },
 		[63] = { .offset = 0xa6, .value = 0x00, },
 		[64] = { .offset = 0xa7, .value = 0x00, },
 		[65] = { .offset = 0xa8, .value = 0x00, },
 		[66] = { .offset = 0xa9, .value = 0x83, },
 		[67] = { .offset = 0xaa, .value = 0x40, },
 		[68] = { .offset = 0xab, .value = 0x32, },
 		[69] = { .offset = 0xac, .value = 0x00, },
 		[70] = { .offset = 0xa4, .value = 0x80, },
 		[71] = { .offset = 0x7e, .value = 0x18, },
 		[72] = { .offset = 0x84, .value = 0x00, },
 		[73] = { .offset = 0x85, .value = 0x00, },
 		[74] = { .offset = 0x86, .value = 0x00, },
 		[75] = { .offset = 0x87, .value = 0x00, },
 		[76] = { .offset = 0x88, .value = 0x00, },
 		[77] = { .offset = 0x89, .value = 0x00, },
 		[78] = { .offset = 0x8a, .value = 0x00, },
 		[79] = { .offset = 0x8b, .value = 0x00, },
 		[80] = { .offset = 0x26, .value = 0x00, },
 		[81] = { .offset = 0x27, .value = 0x00, },
 		[82] = { .offset = 0xad, .value = 0x00, },
 		[83] = { .offset = 0x08, .value = 0x30, }, /* 0x31 */
 		[84] = { .offset = 0x41, .value = 0x00, },
 		[85] = { .offset = 0xc0, .value = 0x07, },
 	},
 	[MODE_1024x768] = {
 		[0] = { .offset = 0x0a, .value = 0x81, },
 		[1] = { .offset = 0x18, .value = 0x07, },
 		[2] = { .offset = 0x19, .value = 0x00, },
 		[3] = { .offset = 0x1a, .value = 0x00, },
 		[4] = { .offset = 0x1b, .value = 0x11, },
 		[5] = { .offset = 0x1c, .value = 0x54, },
 		[6] = { .offset = 0x1d, .value = 0x03, },
 		[7] = { .offset = 0x1e, .value = 0x02, },
 		[8] = { .offset = 0xf3, .value = 0x90, },
 		[9] = { .offset = 0xf9, .value = 0x00, },
 		[10] = { .offset = 0xc1, .value = 0x90, },
 		[11] = { .offset = 0xc2, .value = 0x00, },
 		[12] = { .offset = 0xc3, .value = 0x0f, },
 		[13] = { .offset = 0xc4, .value = 0x03, },
 		[14] = { .offset = 0xc5, .value = 0x16, },
 		[15] = { .offset = 0xc6, .value = 0x00, },
 		[16] = { .offset = 0xc7, .value = 0x02, },
 		[17] = { .offset = 0xc8, .value = 0x02, },
 		[18] = { .offset = 0xf4, .value = 0x00, },
 		[19] = { .offset = 0x80, .value = 0xff, },
 		[20] = { .offset = 0x81, .value = 0x07, },
 		[21] = { .offset = 0x82, .value = 0x3d, },
 		[22] = { .offset = 0x83, .value = 0x05, },
 		[23] = { .offset = 0x94, .value = 0x00, },
 		[24] = { .offset = 0x95, .value = 0x00, },
 		[25] = { .offset = 0x96, .value = 0x05, },
 		[26] = { .offset = 0x97, .value = 0x00, },
 		[27] = { .offset = 0x9a, .value = 0x88, },
 		[28] = { .offset = 0x9b, .value = 0x00, },
 		[29] = { .offset = 0x98, .value = 0x00, },
 		[30] = { .offset = 0x99, .value = 0x00, },
 		[31] = { .offset = 0xf7, .value = 0x88, },
 		[32] = { .offset = 0xf8, .value = 0x0a, },
 		[33] = { .offset = 0x9c, .value = 0x24, },
 		[34] = { .offset = 0x9d, .value = 0x00, },
 		[35] = { .offset = 0x9e, .value = 0x25, },
 		[36] = { .offset = 0x9f, .value = 0x03, },
 		[37] = { .offset = 0xa0, .value = 0x28, },
 		[38] = { .offset = 0xa1, .value = 0x01, },
 		[39] = { .offset = 0xa2, .value = 0x28, },
 		[40] = { .offset = 0xa3, .value = 0x05, },
 		[41] = { .offset = 0xb6, .value = 0x09, },
 		[42] = { .offset = 0xb8, .value = 0x00, },
 		[43] = { .offset = 0xb9, .value = 0xa0, },
 		[44] = { .offset = 0xba, .value = 0x00, },
 		[45] = { .offset = 0xbb, .value = 0x20, },
 		[46] = { .offset = 0x10, .value = 0x00, },
 		[47] = { .offset = 0x11, .value = 0xa0, },
 		[48] = { .offset = 0x12, .value = 0x02, },
 		[49] = { .offset = 0x20, .value = 0x00, },
 		[50] = { .offset = 0x22, .value = 0x00, },
 		[51] = { .offset = 0x23, .value = 0x00, },
 		[52] = { .offset = 0x24, .value = 0x00, },
 		[53] = { .offset = 0x25, .value = 0x00, },
 		[54] = { .offset = 0x8c, .value = 0x10, },
 		[55] = { .offset = 0x8d, .value = 0x02, },
 		[56] = { .offset = 0x8e, .value = 0x10, },
 		[57] = { .offset = 0x8f, .value = 0x00, },
 		[58] = { .offset = 0x90, .value = 0xff, },
 		[59] = { .offset = 0x91, .value = 0x07, },
 		[60] = { .offset = 0x92, .value = 0xa0, },
 		[61] = { .offset = 0x93, .value = 0x02, },
 		[62] = { .offset = 0xa5, .value = 0x00, },
 		[63] = { .offset = 0xa6, .value = 0x00, },
 		[64] = { .offset = 0xa7, .value = 0x00, },
 		[65] = { .offset = 0xa8, .value = 0x00, },
 		[66] = { .offset = 0xa9, .value = 0x04, },
 		[67] = { .offset = 0xaa, .value = 0x70, },
 		[68] = { .offset = 0xab, .value = 0x4f, },
 		[69] = { .offset = 0xac, .value = 0x00, },
 		[70] = { .offset = 0xa4, .value = 0x84, },
 		[71] = { .offset = 0x7e, .value = 0x18, },
 		[72] = { .offset = 0x84, .value = 0x00, },
 		[73] = { .offset = 0x85, .value = 0x00, },
 		[74] = { .offset = 0x86, .value = 0x00, },
 		[75] = { .offset = 0x87, .value = 0x00, },
 		[76] = { .offset = 0x88, .value = 0x00, },
 		[77] = { .offset = 0x89, .value = 0x00, },
 		[78] = { .offset = 0x8a, .value = 0x00, },
 		[79] = { .offset = 0x8b, .value = 0x00, },
 		[80] = { .offset = 0x26, .value = 0x00, },
 		[81] = { .offset = 0x27, .value = 0x00, },
 		[82] = { .offset = 0xad, .value = 0x00, },
 		[83] = { .offset = 0x08, .value = 0x34, }, /* 0x35 */
 		[84] = { .offset = 0x41, .value = 0x00, },
 		[85] = { .offset = 0xc0, .value = 0x01, },
 	},
 };

 static const struct ns2501_reg regs_init[] = {
 	[0] = { .offset = 0x35, .value = 0xff, },
 	[1] = { .offset = 0x34, .value = 0x00, },
 	[2] = { .offset = 0x08, .value = 0x30, },
 };

 struct ns2501_priv {
 	bool quiet;
 	const struct ns2501_reg *regs;
 };

 #define NSPTR(d) ((NS2501Ptr)(d->DriverPrivate.ptr))

 /*
  * For reasons unclear to me, the ns2501 at least on the Fujitsu/Siemens
  * laptops does not react on the i2c bus unless
  * both the PLL is running and the display is configured in its native
  * resolution.
  * This function forces the DVO on, and stores the registers it touches.
  * Afterwards, registers are restored to regular values.
  *
  * This is pretty much a hack, though it works.
  * Without that, ns2501_readb and ns2501_writeb fail
  * when switching the resolution.
  */

 /*
 ** Read a register from the ns2501.
 ** Returns true if successful, false otherwise.
 ** If it returns false, it might be wise to enable the
 ** DVO with the above function.
 */
 static bool ns2501_readb(struct intel_dvo_device *dvo, int addr, uint8_t * ch)
 {
 	struct ns2501_priv *ns = dvo->dev_priv;
 	struct i2c_adapter *adapter = dvo->i2c_bus;
 	u8 out_buf[2];
 	u8 in_buf[2];

 	struct i2c_msg msgs[] = {
 		{
 		 .addr = dvo->slave_addr,
 		 .flags = 0,
 		 .len = 1,
 		 .buf = out_buf,
 		 },
 		{
 		 .addr = dvo->slave_addr,
 		 .flags = I2C_M_RD,
 		 .len = 1,
 		 .buf = in_buf,
 		 }
 	};

 	out_buf[0] = addr;
 	out_buf[1] = 0;

 	if (i2c_transfer(adapter, msgs, 2) == 2) {
 		*ch = in_buf[0];
 		return true;
 	}

 	if (!ns->quiet) {
 		DRM_DEBUG_KMS
 		    ("Unable to read register 0x%02x from %s:0x%02x.\n", addr,
 		     adapter->name, dvo->slave_addr);
 	}

 	return false;
 }

 /*
 ** Write a register to the ns2501.
 ** Returns true if successful, false otherwise.
 ** If it returns false, it might be wise to enable the
 ** DVO with the above function.
 */
 static bool ns2501_writeb(struct intel_dvo_device *dvo, int addr, uint8_t ch)
 {
 	struct ns2501_priv *ns = dvo->dev_priv;
 	struct i2c_adapter *adapter = dvo->i2c_bus;
 	uint8_t out_buf[2];

 	struct i2c_msg msg = {
 		.addr = dvo->slave_addr,
 		.flags = 0,
 		.len = 2,
 		.buf = out_buf,
 	};

 	out_buf[0] = addr;
 	out_buf[1] = ch;

 	if (i2c_transfer(adapter, &msg, 1) == 1) {
 		return true;
 	}

 	if (!ns->quiet) {
 		DRM_DEBUG_KMS("Unable to write register 0x%02x to %s:%d\n",
 			      addr, adapter->name, dvo->slave_addr);
 	}

 	return false;
 }

 /* National Semiconductor 2501 driver for chip on i2c bus
  * scan for the chip on the bus.
  * Hope the VBIOS initialized the PLL correctly so we can
  * talk to it. If not, it will not be seen and not detected.
  * Bummer!
  */
 static bool ns2501_init(struct intel_dvo_device *dvo,
 			struct i2c_adapter *adapter)
 {
 	/* this will detect the NS2501 chip on the specified i2c bus */
 	struct ns2501_priv *ns;
 	unsigned char ch;

 	ns = kzalloc(sizeof(struct ns2501_priv), GFP_KERNEL);
 	if (ns == NULL)
 		return false;

 	dvo->i2c_bus = adapter;
 	dvo->dev_priv = ns;
 	ns->quiet = true;

 	if (!ns2501_readb(dvo, NS2501_VID_LO, &ch))
 		goto out;

 	if (ch != (NS2501_VID & 0xff)) {
 		DRM_DEBUG_KMS("ns2501 not detected got %d: from %s Slave %d.\n",
 			      ch, adapter->name, dvo->slave_addr);
 		goto out;
 	}

 	if (!ns2501_readb(dvo, NS2501_DID_LO, &ch))
 		goto out;

 	if (ch != (NS2501_DID & 0xff)) {
 		DRM_DEBUG_KMS("ns2501 not detected got %d: from %s Slave %d.\n",
 			      ch, adapter->name, dvo->slave_addr);
 		goto out;
 	}
 	ns->quiet = false;

 	DRM_DEBUG_KMS("init ns2501 dvo controller successfully!\n");

 	return true;

 out:
 	kfree(ns);
 	return false;
 }

 static enum drm_connector_status ns2501_detect(struct intel_dvo_device *dvo)
 {
 	/*
 	 * This is a Laptop display, it doesn't have hotplugging.
 	 * Even if not, the detection bit of the 2501 is unreliable as
 	 * it only works for some display types.
 	 * It is even more unreliable as the PLL must be active for
 	 * allowing reading from the chiop.
 	 */
 	return connector_status_connected;
 }

 static enum drm_mode_status ns2501_mode_valid(struct intel_dvo_device *dvo,
 					      struct drm_display_mode *mode)
 {
 	DRM_DEBUG_KMS
 	    ("is mode valid (hdisplay=%d,htotal=%d,vdisplay=%d,vtotal=%d)\n",
 	     mode->hdisplay, mode->htotal, mode->vdisplay, mode->vtotal);

 	/*
 	 * Currently, these are all the modes I have data from.
 	 * More might exist. Unclear how to find the native resolution
 	 * of the panel in here so we could always accept it
 	 * by disabling the scaler.
 	 */
 	if ((mode->hdisplay == 640 && mode->vdisplay == 480 && mode->clock == 25175) ||
 	    (mode->hdisplay == 800 && mode->vdisplay == 600 && mode->clock == 40000) ||
 	    (mode->hdisplay == 1024 && mode->vdisplay == 768 && mode->clock == 65000)) {
 		return MODE_OK;
 	} else {
 		return MODE_ONE_SIZE;	/* Is this a reasonable error? */
 	}
 }

 static void ns2501_mode_set(struct intel_dvo_device *dvo,
 			    struct drm_display_mode *mode,
 			    struct drm_display_mode *adjusted_mode)
 {
 	struct ns2501_priv *ns = (struct ns2501_priv *)(dvo->dev_priv);
 	int mode_idx, i;

 	DRM_DEBUG_KMS
 	    ("set mode (hdisplay=%d,htotal=%d,vdisplay=%d,vtotal=%d).\n",
 	     mode->hdisplay, mode->htotal, mode->vdisplay, mode->vtotal);

 	if (mode->hdisplay == 640 && mode->vdisplay == 480)
 		mode_idx = MODE_640x480;
 	else if (mode->hdisplay == 800 && mode->vdisplay == 600)
 		mode_idx = MODE_800x600;
 	else if (mode->hdisplay == 1024 && mode->vdisplay == 768)
 		mode_idx = MODE_1024x768;
 	else
 		return;

 	/* Hopefully doing it every time won't hurt... */
 	for (i = 0; i < ARRAY_SIZE(regs_init); i++)
 		ns2501_writeb(dvo, regs_init[i].offset, regs_init[i].value);

 	ns->regs = regs_1024x768[mode_idx];

 	for (i = 0; i < 84; i++)
 		ns2501_writeb(dvo, ns->regs[i].offset, ns->regs[i].value);
 }

 /* set the NS2501 power state */
 static bool ns2501_get_hw_state(struct intel_dvo_device *dvo)
 {
 	unsigned char ch;

 	if (!ns2501_readb(dvo, NS2501_REG8, &ch))
 		return false;

 	return ch & NS2501_8_PD;
 }

 /* set the NS2501 power state */
 static void ns2501_dpms(struct intel_dvo_device *dvo, bool enable)
 {
 	struct ns2501_priv *ns = (struct ns2501_priv *)(dvo->dev_priv);

 	DRM_DEBUG_KMS("Trying set the dpms of the DVO to %i\n", enable);

 	if (enable) {
 		if (WARN_ON(ns->regs[83].offset != 0x08 ||
 			    ns->regs[84].offset != 0x41 ||
 			    ns->regs[85].offset != 0xc0))
 			return;

 		ns2501_writeb(dvo, 0xc0, ns->regs[85].value | 0x08);

 		ns2501_writeb(dvo, 0x41, ns->regs[84].value);

 		ns2501_writeb(dvo, 0x34, 0x01);
 		msleep(15);

 		ns2501_writeb(dvo, 0x08, 0x35);
 		if (!(ns->regs[83].value & NS2501_8_BPAS))
 			ns2501_writeb(dvo, 0x08, 0x31);
 		msleep(200);

 		ns2501_writeb(dvo, 0x34, 0x03);

 		ns2501_writeb(dvo, 0xc0, ns->regs[85].value);
 	} else {
 		ns2501_writeb(dvo, 0x34, 0x01);
 		msleep(200);

 		ns2501_writeb(dvo, 0x08, 0x34);
 		msleep(15);

 		ns2501_writeb(dvo, 0x34, 0x00);
 	}
 }

 static void ns2501_destroy(struct intel_dvo_device *dvo)
 {
 	struct ns2501_priv *ns = dvo->dev_priv;

 	if (ns) {
 		kfree(ns);
 		dvo->dev_priv = NULL;
 	}
 }

 struct intel_dvo_dev_ops ns2501_ops = {
 	.init = ns2501_init,
 	.detect = ns2501_detect,
 	.mode_valid = ns2501_mode_valid,
 	.mode_set = ns2501_mode_set,
 	.dpms = ns2501_dpms,
 	.get_hw_state = ns2501_get_hw_state,
 	.destroy = ns2501_destroy,
 };
	/*
	*
	* Copyright (c) 2012 Gilles Dartiguelongue, Thomas Richter
	*
	* All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sub license, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice (including the
	* next paragraph) shall be included in all copies or substantial portions
	* of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
	* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*
	*/

	#include "dvo.h"
	#include "i915_reg.h"
	#include "i915_drv.h"

	#define NS2501_VID 0x1305
	#define NS2501_DID 0x6726

	#define NS2501_VID_LO 0x00
	#define NS2501_VID_HI 0x01
	#define NS2501_DID_LO 0x02
	#define NS2501_DID_HI 0x03
	#define NS2501_REV 0x04
	#define NS2501_RSVD 0x05
	#define NS2501_FREQ_LO 0x06
	#define NS2501_FREQ_HI 0x07

	#define NS2501_REG8 0x08
	#define NS2501_8_VEN (1<<5)
	#define NS2501_8_HEN (1<<4)
	#define NS2501_8_DSEL (1<<3)
	#define NS2501_8_BPAS (1<<2)
	#define NS2501_8_RSVD (1<<1)
	#define NS2501_8_PD (1<<0)

	#define NS2501_REG9 0x09
	#define NS2501_9_VLOW (1<<7)
	#define NS2501_9_MSEL_MASK (0x7<<4)
	#define NS2501_9_TSEL (1<<3)
	#define NS2501_9_RSEN (1<<2)
	#define NS2501_9_RSVD (1<<1)
	#define NS2501_9_MDI (1<<0)

	#define NS2501_REGC 0x0c

	enum {
	MODE_640x480,
	MODE_800x600,
	MODE_1024x768,
	};

	struct ns2501_reg {
	uint8_t offset;
	uint8_t value;
	};

	/*
	* Magic values based on what the BIOS on
	* Fujitsu-Siemens Lifebook S6010 programs (1024x768 panel).
	*/
	static const struct ns2501_reg regs_1024x768[][86] = {
	[MODE_640x480] = {
	[0] = { .offset = 0x0a, .value = 0x81, },
	[1] = { .offset = 0x18, .value = 0x07, },
	[2] = { .offset = 0x19, .value = 0x00, },
	[3] = { .offset = 0x1a, .value = 0x00, },
	[4] = { .offset = 0x1b, .value = 0x11, },
	[5] = { .offset = 0x1c, .value = 0x54, },
	[6] = { .offset = 0x1d, .value = 0x03, },
	[7] = { .offset = 0x1e, .value = 0x02, },
	[8] = { .offset = 0xf3, .value = 0x90, },
	[9] = { .offset = 0xf9, .value = 0x00, },
	[10] = { .offset = 0xc1, .value = 0x90, },
	[11] = { .offset = 0xc2, .value = 0x00, },
	[12] = { .offset = 0xc3, .value = 0x0f, },
	[13] = { .offset = 0xc4, .value = 0x03, },
	[14] = { .offset = 0xc5, .value = 0x16, },
	[15] = { .offset = 0xc6, .value = 0x00, },
	[16] = { .offset = 0xc7, .value = 0x02, },
	[17] = { .offset = 0xc8, .value = 0x02, },
	[18] = { .offset = 0xf4, .value = 0x00, },
	[19] = { .offset = 0x80, .value = 0xff, },
	[20] = { .offset = 0x81, .value = 0x07, },
	[21] = { .offset = 0x82, .value = 0x3d, },
	[22] = { .offset = 0x83, .value = 0x05, },
	[23] = { .offset = 0x94, .value = 0x00, },
	[24] = { .offset = 0x95, .value = 0x00, },
	[25] = { .offset = 0x96, .value = 0x05, },
	[26] = { .offset = 0x97, .value = 0x00, },
	[27] = { .offset = 0x9a, .value = 0x88, },
	[28] = { .offset = 0x9b, .value = 0x00, },
	[29] = { .offset = 0x98, .value = 0x00, },
	[30] = { .offset = 0x99, .value = 0x00, },
	[31] = { .offset = 0xf7, .value = 0x88, },
	[32] = { .offset = 0xf8, .value = 0x0a, },
	[33] = { .offset = 0x9c, .value = 0x24, },
	[34] = { .offset = 0x9d, .value = 0x00, },
	[35] = { .offset = 0x9e, .value = 0x25, },
	[36] = { .offset = 0x9f, .value = 0x03, },
	[37] = { .offset = 0xa0, .value = 0x28, },
	[38] = { .offset = 0xa1, .value = 0x01, },
	[39] = { .offset = 0xa2, .value = 0x28, },
	[40] = { .offset = 0xa3, .value = 0x05, },
	[41] = { .offset = 0xb6, .value = 0x09, },
	[42] = { .offset = 0xb8, .value = 0x00, },
	[43] = { .offset = 0xb9, .value = 0xa0, },
	[44] = { .offset = 0xba, .value = 0x00, },
	[45] = { .offset = 0xbb, .value = 0x20, },
	[46] = { .offset = 0x10, .value = 0x00, },
	[47] = { .offset = 0x11, .value = 0xa0, },
	[48] = { .offset = 0x12, .value = 0x02, },
	[49] = { .offset = 0x20, .value = 0x00, },
	[50] = { .offset = 0x22, .value = 0x00, },
	[51] = { .offset = 0x23, .value = 0x00, },
	[52] = { .offset = 0x24, .value = 0x00, },
	[53] = { .offset = 0x25, .value = 0x00, },
	[54] = { .offset = 0x8c, .value = 0x10, },
	[55] = { .offset = 0x8d, .value = 0x02, },
	[56] = { .offset = 0x8e, .value = 0x10, },
	[57] = { .offset = 0x8f, .value = 0x00, },
	[58] = { .offset = 0x90, .value = 0xff, },
	[59] = { .offset = 0x91, .value = 0x07, },
	[60] = { .offset = 0x92, .value = 0xa0, },
	[61] = { .offset = 0x93, .value = 0x02, },
	[62] = { .offset = 0xa5, .value = 0x00, },
	[63] = { .offset = 0xa6, .value = 0x00, },
	[64] = { .offset = 0xa7, .value = 0x00, },
	[65] = { .offset = 0xa8, .value = 0x00, },
	[66] = { .offset = 0xa9, .value = 0x04, },
	[67] = { .offset = 0xaa, .value = 0x70, },
	[68] = { .offset = 0xab, .value = 0x4f, },
	[69] = { .offset = 0xac, .value = 0x00, },
	[70] = { .offset = 0xa4, .value = 0x84, },
	[71] = { .offset = 0x7e, .value = 0x18, },
	[72] = { .offset = 0x84, .value = 0x00, },
	[73] = { .offset = 0x85, .value = 0x00, },
	[74] = { .offset = 0x86, .value = 0x00, },
	[75] = { .offset = 0x87, .value = 0x00, },
	[76] = { .offset = 0x88, .value = 0x00, },
	[77] = { .offset = 0x89, .value = 0x00, },
	[78] = { .offset = 0x8a, .value = 0x00, },
	[79] = { .offset = 0x8b, .value = 0x00, },
	[80] = { .offset = 0x26, .value = 0x00, },
	[81] = { .offset = 0x27, .value = 0x00, },
	[82] = { .offset = 0xad, .value = 0x00, },
	[83] = { .offset = 0x08, .value = 0x30, }, /* 0x31 */
	[84] = { .offset = 0x41, .value = 0x00, },
	[85] = { .offset = 0xc0, .value = 0x05, },
	},
	[MODE_800x600] = {
	[0] = { .offset = 0x0a, .value = 0x81, },
	[1] = { .offset = 0x18, .value = 0x07, },
	[2] = { .offset = 0x19, .value = 0x00, },
	[3] = { .offset = 0x1a, .value = 0x00, },
	[4] = { .offset = 0x1b, .value = 0x19, },
	[5] = { .offset = 0x1c, .value = 0x64, },
	[6] = { .offset = 0x1d, .value = 0x02, },
	[7] = { .offset = 0x1e, .value = 0x02, },
	[8] = { .offset = 0xf3, .value = 0x90, },
	[9] = { .offset = 0xf9, .value = 0x00, },
	[10] = { .offset = 0xc1, .value = 0xd7, },
	[11] = { .offset = 0xc2, .value = 0x00, },
	[12] = { .offset = 0xc3, .value = 0xf8, },
	[13] = { .offset = 0xc4, .value = 0x03, },
	[14] = { .offset = 0xc5, .value = 0x1a, },
	[15] = { .offset = 0xc6, .value = 0x00, },
	[16] = { .offset = 0xc7, .value = 0x73, },
	[17] = { .offset = 0xc8, .value = 0x02, },
	[18] = { .offset = 0xf4, .value = 0x00, },
	[19] = { .offset = 0x80, .value = 0x27, },
	[20] = { .offset = 0x81, .value = 0x03, },
	[21] = { .offset = 0x82, .value = 0x41, },
	[22] = { .offset = 0x83, .value = 0x05, },
	[23] = { .offset = 0x94, .value = 0x00, },
	[24] = { .offset = 0x95, .value = 0x00, },
	[25] = { .offset = 0x96, .value = 0x05, },
	[26] = { .offset = 0x97, .value = 0x00, },
	[27] = { .offset = 0x9a, .value = 0x88, },
	[28] = { .offset = 0x9b, .value = 0x00, },
	[29] = { .offset = 0x98, .value = 0x00, },
	[30] = { .offset = 0x99, .value = 0x00, },
	[31] = { .offset = 0xf7, .value = 0x88, },
	[32] = { .offset = 0xf8, .value = 0x06, },
	[33] = { .offset = 0x9c, .value = 0x23, },
	[34] = { .offset = 0x9d, .value = 0x00, },
	[35] = { .offset = 0x9e, .value = 0x25, },
	[36] = { .offset = 0x9f, .value = 0x03, },
	[37] = { .offset = 0xa0, .value = 0x28, },
	[38] = { .offset = 0xa1, .value = 0x01, },
	[39] = { .offset = 0xa2, .value = 0x28, },
	[40] = { .offset = 0xa3, .value = 0x05, },
	[41] = { .offset = 0xb6, .value = 0x09, },
	[42] = { .offset = 0xb8, .value = 0x30, },
	[43] = { .offset = 0xb9, .value = 0xc8, },
	[44] = { .offset = 0xba, .value = 0x00, },
	[45] = { .offset = 0xbb, .value = 0x20, },
	[46] = { .offset = 0x10, .value = 0x20, },
	[47] = { .offset = 0x11, .value = 0xc8, },
	[48] = { .offset = 0x12, .value = 0x02, },
	[49] = { .offset = 0x20, .value = 0x00, },
	[50] = { .offset = 0x22, .value = 0x00, },
	[51] = { .offset = 0x23, .value = 0x00, },
	[52] = { .offset = 0x24, .value = 0x00, },
	[53] = { .offset = 0x25, .value = 0x00, },
	[54] = { .offset = 0x8c, .value = 0x10, },
	[55] = { .offset = 0x8d, .value = 0x02, },
	[56] = { .offset = 0x8e, .value = 0x04, },
	[57] = { .offset = 0x8f, .value = 0x00, },
	[58] = { .offset = 0x90, .value = 0xff, },
	[59] = { .offset = 0x91, .value = 0x07, },
	[60] = { .offset = 0x92, .value = 0xa0, },
	[61] = { .offset = 0x93, .value = 0x02, },
	[62] = { .offset = 0xa5, .value = 0x00, },
	[63] = { .offset = 0xa6, .value = 0x00, },
	[64] = { .offset = 0xa7, .value = 0x00, },
	[65] = { .offset = 0xa8, .value = 0x00, },
	[66] = { .offset = 0xa9, .value = 0x83, },
	[67] = { .offset = 0xaa, .value = 0x40, },
	[68] = { .offset = 0xab, .value = 0x32, },
	[69] = { .offset = 0xac, .value = 0x00, },
	[70] = { .offset = 0xa4, .value = 0x80, },
	[71] = { .offset = 0x7e, .value = 0x18, },
	[72] = { .offset = 0x84, .value = 0x00, },
	[73] = { .offset = 0x85, .value = 0x00, },
	[74] = { .offset = 0x86, .value = 0x00, },
	[75] = { .offset = 0x87, .value = 0x00, },
	[76] = { .offset = 0x88, .value = 0x00, },
	[77] = { .offset = 0x89, .value = 0x00, },
	[78] = { .offset = 0x8a, .value = 0x00, },
	[79] = { .offset = 0x8b, .value = 0x00, },
	[80] = { .offset = 0x26, .value = 0x00, },
	[81] = { .offset = 0x27, .value = 0x00, },
	[82] = { .offset = 0xad, .value = 0x00, },
	[83] = { .offset = 0x08, .value = 0x30, }, /* 0x31 */
	[84] = { .offset = 0x41, .value = 0x00, },
	[85] = { .offset = 0xc0, .value = 0x07, },
	},
	[MODE_1024x768] = {
	[0] = { .offset = 0x0a, .value = 0x81, },
	[1] = { .offset = 0x18, .value = 0x07, },
	[2] = { .offset = 0x19, .value = 0x00, },
	[3] = { .offset = 0x1a, .value = 0x00, },
	[4] = { .offset = 0x1b, .value = 0x11, },
	[5] = { .offset = 0x1c, .value = 0x54, },
	[6] = { .offset = 0x1d, .value = 0x03, },
	[7] = { .offset = 0x1e, .value = 0x02, },
	[8] = { .offset = 0xf3, .value = 0x90, },
	[9] = { .offset = 0xf9, .value = 0x00, },
	[10] = { .offset = 0xc1, .value = 0x90, },
	[11] = { .offset = 0xc2, .value = 0x00, },
	[12] = { .offset = 0xc3, .value = 0x0f, },
	[13] = { .offset = 0xc4, .value = 0x03, },
	[14] = { .offset = 0xc5, .value = 0x16, },
	[15] = { .offset = 0xc6, .value = 0x00, },
	[16] = { .offset = 0xc7, .value = 0x02, },
	[17] = { .offset = 0xc8, .value = 0x02, },
	[18] = { .offset = 0xf4, .value = 0x00, },
	[19] = { .offset = 0x80, .value = 0xff, },
	[20] = { .offset = 0x81, .value = 0x07, },
	[21] = { .offset = 0x82, .value = 0x3d, },
	[22] = { .offset = 0x83, .value = 0x05, },
	[23] = { .offset = 0x94, .value = 0x00, },
	[24] = { .offset = 0x95, .value = 0x00, },
	[25] = { .offset = 0x96, .value = 0x05, },
	[26] = { .offset = 0x97, .value = 0x00, },
	[27] = { .offset = 0x9a, .value = 0x88, },
	[28] = { .offset = 0x9b, .value = 0x00, },
	[29] = { .offset = 0x98, .value = 0x00, },
	[30] = { .offset = 0x99, .value = 0x00, },
	[31] = { .offset = 0xf7, .value = 0x88, },
	[32] = { .offset = 0xf8, .value = 0x0a, },
	[33] = { .offset = 0x9c, .value = 0x24, },
	[34] = { .offset = 0x9d, .value = 0x00, },
	[35] = { .offset = 0x9e, .value = 0x25, },
	[36] = { .offset = 0x9f, .value = 0x03, },
	[37] = { .offset = 0xa0, .value = 0x28, },
	[38] = { .offset = 0xa1, .value = 0x01, },
	[39] = { .offset = 0xa2, .value = 0x28, },
	[40] = { .offset = 0xa3, .value = 0x05, },
	[41] = { .offset = 0xb6, .value = 0x09, },
	[42] = { .offset = 0xb8, .value = 0x00, },
	[43] = { .offset = 0xb9, .value = 0xa0, },
	[44] = { .offset = 0xba, .value = 0x00, },
	[45] = { .offset = 0xbb, .value = 0x20, },
	[46] = { .offset = 0x10, .value = 0x00, },
	[47] = { .offset = 0x11, .value = 0xa0, },
	[48] = { .offset = 0x12, .value = 0x02, },
	[49] = { .offset = 0x20, .value = 0x00, },
	[50] = { .offset = 0x22, .value = 0x00, },
	[51] = { .offset = 0x23, .value = 0x00, },
	[52] = { .offset = 0x24, .value = 0x00, },
	[53] = { .offset = 0x25, .value = 0x00, },
	[54] = { .offset = 0x8c, .value = 0x10, },
	[55] = { .offset = 0x8d, .value = 0x02, },
	[56] = { .offset = 0x8e, .value = 0x10, },
	[57] = { .offset = 0x8f, .value = 0x00, },
	[58] = { .offset = 0x90, .value = 0xff, },
	[59] = { .offset = 0x91, .value = 0x07, },
	[60] = { .offset = 0x92, .value = 0xa0, },
	[61] = { .offset = 0x93, .value = 0x02, },
	[62] = { .offset = 0xa5, .value = 0x00, },
	[63] = { .offset = 0xa6, .value = 0x00, },
	[64] = { .offset = 0xa7, .value = 0x00, },
	[65] = { .offset = 0xa8, .value = 0x00, },
	[66] = { .offset = 0xa9, .value = 0x04, },
	[67] = { .offset = 0xaa, .value = 0x70, },
	[68] = { .offset = 0xab, .value = 0x4f, },
	[69] = { .offset = 0xac, .value = 0x00, },
	[70] = { .offset = 0xa4, .value = 0x84, },
	[71] = { .offset = 0x7e, .value = 0x18, },
	[72] = { .offset = 0x84, .value = 0x00, },
	[73] = { .offset = 0x85, .value = 0x00, },
	[74] = { .offset = 0x86, .value = 0x00, },
	[75] = { .offset = 0x87, .value = 0x00, },
	[76] = { .offset = 0x88, .value = 0x00, },
	[77] = { .offset = 0x89, .value = 0x00, },
	[78] = { .offset = 0x8a, .value = 0x00, },
	[79] = { .offset = 0x8b, .value = 0x00, },
	[80] = { .offset = 0x26, .value = 0x00, },
	[81] = { .offset = 0x27, .value = 0x00, },
	[82] = { .offset = 0xad, .value = 0x00, },
	[83] = { .offset = 0x08, .value = 0x34, }, /* 0x35 */
	[84] = { .offset = 0x41, .value = 0x00, },
	[85] = { .offset = 0xc0, .value = 0x01, },
	},
	};

	static const struct ns2501_reg regs_init[] = {
	[0] = { .offset = 0x35, .value = 0xff, },
	[1] = { .offset = 0x34, .value = 0x00, },
	[2] = { .offset = 0x08, .value = 0x30, },
	};

	struct ns2501_priv {
	bool quiet;
	const struct ns2501_reg *regs;
	};

	#define NSPTR(d) ((NS2501Ptr)(d->DriverPrivate.ptr))

	/*
	* For reasons unclear to me, the ns2501 at least on the Fujitsu/Siemens
	* laptops does not react on the i2c bus unless
	* both the PLL is running and the display is configured in its native
	* resolution.
	* This function forces the DVO on, and stores the registers it touches.
	* Afterwards, registers are restored to regular values.
	*
	* This is pretty much a hack, though it works.
	* Without that, ns2501_readb and ns2501_writeb fail
	* when switching the resolution.
	*/

	/*
	** Read a register from the ns2501.
	** Returns true if successful, false otherwise.
	** If it returns false, it might be wise to enable the
	** DVO with the above function.
	*/
	static bool ns2501_readb(struct intel_dvo_device dvo, int addr, uint8_t ch)
	{
	struct ns2501_priv *ns = dvo->dev_priv;
	struct i2c_adapter *adapter = dvo->i2c_bus;
	u8 out_buf[2];
	u8 in_buf[2];

	struct i2c_msg msgs[] = {
	{
	.addr = dvo->slave_addr,
	.flags = 0,
	.len = 1,
	.buf = out_buf,
	},
	{
	.addr = dvo->slave_addr,
	.flags = I2C_M_RD,
	.len = 1,
	.buf = in_buf,
	}
	};

	out_buf[0] = addr;
	out_buf[1] = 0;

	if (i2c_transfer(adapter, msgs, 2) == 2) {
	*ch = in_buf[0];
	return true;
	}

	if (!ns->quiet) {
	DRM_DEBUG_KMS
	("Unable to read register 0x%02x from %s:0x%02x.\n", addr,
	adapter->name, dvo->slave_addr);
	}

	return false;
	}

	/*
	** Write a register to the ns2501.
	** Returns true if successful, false otherwise.
	** If it returns false, it might be wise to enable the
	** DVO with the above function.
	*/
	static bool ns2501_writeb(struct intel_dvo_device *dvo, int addr, uint8_t ch)
	{
	struct ns2501_priv *ns = dvo->dev_priv;
	struct i2c_adapter *adapter = dvo->i2c_bus;
	uint8_t out_buf[2];

	struct i2c_msg msg = {
	.addr = dvo->slave_addr,
	.flags = 0,
	.len = 2,
	.buf = out_buf,
	};

	out_buf[0] = addr;
	out_buf[1] = ch;

	if (i2c_transfer(adapter, &msg, 1) == 1) {
	return true;
	}

	if (!ns->quiet) {
	DRM_DEBUG_KMS("Unable to write register 0x%02x to %s:%d\n",
	addr, adapter->name, dvo->slave_addr);
	}

	return false;
	}

	/* National Semiconductor 2501 driver for chip on i2c bus
	* scan for the chip on the bus.
	* Hope the VBIOS initialized the PLL correctly so we can
	* talk to it. If not, it will not be seen and not detected.
	* Bummer!
	*/
	static bool ns2501_init(struct intel_dvo_device *dvo,
	struct i2c_adapter *adapter)
	{
	/* this will detect the NS2501 chip on the specified i2c bus */
	struct ns2501_priv *ns;
	unsigned char ch;

	ns = kzalloc(sizeof(struct ns2501_priv), GFP_KERNEL);
	if (ns == NULL)
	return false;

	dvo->i2c_bus = adapter;
	dvo->dev_priv = ns;
	ns->quiet = true;

	if (!ns2501_readb(dvo, NS2501_VID_LO, &ch))
	goto out;

	if (ch != (NS2501_VID & 0xff)) {
	DRM_DEBUG_KMS("ns2501 not detected got %d: from %s Slave %d.\n",
	ch, adapter->name, dvo->slave_addr);
	goto out;
	}

	if (!ns2501_readb(dvo, NS2501_DID_LO, &ch))
	goto out;

	if (ch != (NS2501_DID & 0xff)) {
	DRM_DEBUG_KMS("ns2501 not detected got %d: from %s Slave %d.\n",
	ch, adapter->name, dvo->slave_addr);
	goto out;
	}
	ns->quiet = false;

	DRM_DEBUG_KMS("init ns2501 dvo controller successfully!\n");

	return true;

	out:
	kfree(ns);
	return false;
	}

	static enum drm_connector_status ns2501_detect(struct intel_dvo_device *dvo)
	{
	/*
	* This is a Laptop display, it doesn't have hotplugging.
	* Even if not, the detection bit of the 2501 is unreliable as
	* it only works for some display types.
	* It is even more unreliable as the PLL must be active for
	* allowing reading from the chiop.
	*/
	return connector_status_connected;
	}

	static enum drm_mode_status ns2501_mode_valid(struct intel_dvo_device *dvo,
	struct drm_display_mode *mode)
	{
	DRM_DEBUG_KMS
	("is mode valid (hdisplay=%d,htotal=%d,vdisplay=%d,vtotal=%d)\n",
	mode->hdisplay, mode->htotal, mode->vdisplay, mode->vtotal);

	/*
	* Currently, these are all the modes I have data from.
	* More might exist. Unclear how to find the native resolution
	* of the panel in here so we could always accept it
	* by disabling the scaler.
	*/
	if ((mode->hdisplay == 640 && mode->vdisplay == 480 && mode->clock == 25175) \|\|
	(mode->hdisplay == 800 && mode->vdisplay == 600 && mode->clock == 40000) \|\|
	(mode->hdisplay == 1024 && mode->vdisplay == 768 && mode->clock == 65000)) {
	return MODE_OK;
	} else {
	return MODE_ONE_SIZE; /* Is this a reasonable error? */
	}
	}

	static void ns2501_mode_set(struct intel_dvo_device *dvo,
	struct drm_display_mode *mode,
	struct drm_display_mode *adjusted_mode)
	{
	struct ns2501_priv ns = (struct ns2501_priv )(dvo->dev_priv);
	int mode_idx, i;

	DRM_DEBUG_KMS
	("set mode (hdisplay=%d,htotal=%d,vdisplay=%d,vtotal=%d).\n",
	mode->hdisplay, mode->htotal, mode->vdisplay, mode->vtotal);

	if (mode->hdisplay == 640 && mode->vdisplay == 480)
	mode_idx = MODE_640x480;
	else if (mode->hdisplay == 800 && mode->vdisplay == 600)
	mode_idx = MODE_800x600;
	else if (mode->hdisplay == 1024 && mode->vdisplay == 768)
	mode_idx = MODE_1024x768;
	else
	return;

	/* Hopefully doing it every time won't hurt... */
	for (i = 0; i < ARRAY_SIZE(regs_init); i++)
	ns2501_writeb(dvo, regs_init[i].offset, regs_init[i].value);

	ns->regs = regs_1024x768[mode_idx];

	for (i = 0; i < 84; i++)
	ns2501_writeb(dvo, ns->regs[i].offset, ns->regs[i].value);
	}

	/* set the NS2501 power state */
	static bool ns2501_get_hw_state(struct intel_dvo_device *dvo)
	{
	unsigned char ch;

	if (!ns2501_readb(dvo, NS2501_REG8, &ch))
	return false;

	return ch & NS2501_8_PD;
	}

	/* set the NS2501 power state */
	static void ns2501_dpms(struct intel_dvo_device *dvo, bool enable)
	{
	struct ns2501_priv ns = (struct ns2501_priv )(dvo->dev_priv);

	DRM_DEBUG_KMS("Trying set the dpms of the DVO to %i\n", enable);

	if (enable) {
	if (WARN_ON(ns->regs[83].offset != 0x08 \|\|
	ns->regs[84].offset != 0x41 \|\|
	ns->regs[85].offset != 0xc0))
	return;

	ns2501_writeb(dvo, 0xc0, ns->regs[85].value \| 0x08);

	ns2501_writeb(dvo, 0x41, ns->regs[84].value);

	ns2501_writeb(dvo, 0x34, 0x01);
	msleep(15);

	ns2501_writeb(dvo, 0x08, 0x35);
	if (!(ns->regs[83].value & NS2501_8_BPAS))
	ns2501_writeb(dvo, 0x08, 0x31);
	msleep(200);

	ns2501_writeb(dvo, 0x34, 0x03);

	ns2501_writeb(dvo, 0xc0, ns->regs[85].value);
	} else {
	ns2501_writeb(dvo, 0x34, 0x01);
	msleep(200);

	ns2501_writeb(dvo, 0x08, 0x34);
	msleep(15);

	ns2501_writeb(dvo, 0x34, 0x00);
	}
	}

	static void ns2501_destroy(struct intel_dvo_device *dvo)
	{
	struct ns2501_priv *ns = dvo->dev_priv;

	if (ns) {
	kfree(ns);
	dvo->dev_priv = NULL;
	}
	}

	struct intel_dvo_dev_ops ns2501_ops = {
	.init = ns2501_init,
	.detect = ns2501_detect,
	.mode_valid = ns2501_mode_valid,
	.mode_set = ns2501_mode_set,
	.dpms = ns2501_dpms,
	.get_hw_state = ns2501_get_hw_state,
	.destroy = ns2501_destroy,
	};